Prescrotal urethrotomy - behind the os penis



NEPHROLOGY AND UROLOGYSurgerySurgical procedures involving the upper urinary tract of small animal patients are ndicated for a variety of diagnostic, prognostic or therapeutic reasons. Patients with diseases of the upper urinary tract frequently present with symptoms of renal disease or renal failure. Successful surgery relies on appropriate evaluation, diagnosis and medical stabilization of patients that are azotaemic or uraemic. Knowledge of regional anatomy, including vascular supply and nervous innervation, is extremely important, as are specific evaluation of renal function and choice of appropriate anaestehtc agents. In addition, application of appropriate surgical techniques to minimize soft tissue trauma is essential. Improtant considerations for successful urinary tract surgery are as follows:Minimize haemorrhageMaintain luminal diametersEstablish a water tight sealEliminate tensionUse appropriate size and type of suture materialSURGICAL PROCEDURES OF THE KIDNEYNEPHRECTOMYBefore removing one of the kidneys, always examine the healthy contralateral organ. It is not uncommon for an animal to have only one kidney, or to have bilateral renal disease.If one diseased or severely traumatized kidney is removed, the remaining kidney will undergo hypertrophy (no newly nephrons are formed) to a point where it can functionally assume about 80% of the workload of two kidneys.Unilateral ureteronephrectomy is indicated as treatment for the following conditions:extensive ureteral or renal traumarenal or perirenal abscessessolitary renal cysts causing serious renal dysfunctionunilateral hydronephrosis, resulting from an incorrectable obstruction of the ureter or renal pelvispolycystic renal disease with advanced pyelonephritisrenal adenocarcinoma without lung metastasisectopic ureter with hydro-ureter or hydronephrosisavulsion of the renal pedicle or uncontrollable haemorrhageNephrectomy is seldom performed when the vascular supply and architecture of the kidney are normal. In instances with hydronephrosis or pyelonephritis, if there is at least 1 to 2 cm or more of the cortical and medullary parenchyma remaining, an attempt should be made to try and save the affected kidney. This is especially important if both kidneys are involved and the cause can potentially be treated by surgical drainage or by medical means.PARTIAL NEPHRECTOMYOn rare occasion focal renal lesions in the cranial or caudal pole of the kidney, or a disruption of one-half of the kidney as a result of trauma, may allow the surgeon to leave viable and functional renal tissue.It is of paramount importance that the ureter is still intact and functional when a portion of the kidney is to be removed. The blood supply should also be intact. Particular attention should be directed to a double arterial supply to the kidney, because each artery supplies a distinct portion of the kidney without any inter-arterial connections.References1.Rosin E. Nephrectomy, In: Current Techniques in Small Animal Surgery, Bojrab MJ (ed.) second edition, Lea & Febiger, Philadelphia 1983. Pp. 293 - 2952.Edwards D F. Percutaneous renal biopsy, In: Current Techniques in Small Animal Surgery, Bojrab MJ (ed.) second edition, Lea & Febiger, Philadelphia 1983 pp 297 - 3043.Gambardella P C, Archibald J. Urinary System - Surgical procedures, In: Canine and Feline Surgery, Archibald J and Catcott E J (eds.), American Veterinary Publications, Inc. Santa Barbara, California 1984 pp. 377 - 383SURGICAL MANAGEMENT OF CYSTIC AND URETHRAL CALCULI IN THE DOGUrinary calculi most often occur in dogs between 3 and 9 years of age. Certain breeds seem to have a higher-that-normal incidence of calculi formation:SchnauzersCorgisDachhundsBulldogsBeaglesPoodlesDalmationsPugsBassettsTerriersNB: More than 50% of cases with urinary calculi have a positive urinary bacterial culture. (UTI)Most calculi are radiopaque and are found in the urinary bladder or the urethra just behind the os penis. Radiolucent calculi also occur, and may look just like air bubbles in the urethra or bladder with positive contrast studies.Surgical removal of calculi is the most frequently used method to treat calculi in small animal patients. Intra-operative decisions are made with the knowledge that calculi can occur in multiple locations. The surgical procedure may include correction of anatomical defects or the creation of a wider urethral opening.Treatment for obstructive urolithiasis in the dogThe distended or overfilled bladder must first be relieved by cystocentesis with a syringe and 22-gauge needle. The dog must not move during needle penetration of the bladder.NB: Manual compression of a distended bladder may cause it to rupture!An attempt is made to pass a well lubricated 3,5 French gauge soft rubber urinary catheter or feeding tube beyond the obstruction and into the bladder. Use Sterile K-Y gel? for lubrication and introduce the catheter aseptic through a window drape.Urethral hydropulsion:The technique of urethral hydropulsion will occasionally force the calculi out of the distal urethral opening or back into the bladder.Smooth muscle antispasmodic agents like "Isaverin?" or Buscopan?" should be given if the animal is not anaesthetised, and a urethral catheter passed to establish urine outflow. General anaesthetic provides the best relaxation of the urethral musculature.In this technique, a large urethral catheter is passed into the external urethral orifice. A 10 ml syringe filled with mixed saline and K-Y gel? is attached to the catheter. The saline and K-Y gel is mixed beforehand with a "Y"-type stopcock connected between two 20 ml syringes. One syringe contains 15 ml saline and the other one contains 15 ml K-Y gel. The two solutions are squeezed from one syringe to the other to thoroughly mix these two solutions. The penile urethra is compressed around the catheter using digital pressure.An assistant inserts his gloved finger into the dog's rectum and presses the pelvic urethra down against the ischium to close it. A bolus of saline + K-Y gel mixture is injected into the catheter to distend the urethra between the two points of compression.The catheter is then rapidly removed, while digital compression on the pelvic urethra is maintained. The saline will be forcefully expelled from the urethra, and small calculi may be carried cranially by the fluid mixture. It may be necessary to repeat this procedure several times.When the calculi are too large to pass through the distal urethra, they can sometimes be back-flushed to the urinary bladder. After injecting a bolus of saline under pressure, the digital compression of the pelvic urethra is rapidly released, while the catheter is maintained inside the penile urethra. The forceful movement of saline may carry the calculi into the urinary bladder. This urethral hydropulsion technique facilitated passage of the urinary catheter if the stones are not too big, otherwise the calculi would not dislodge and an emergency pre-scrotal urethrotomy operation has to be performed just caudal to the os penis.Removal of urethral calculi by hydropulsion1.Urethral calculus originating from the bladder is lodged behind the os penis.2.Dilation of the urethral lumen by injecting saline with pressure. Digital pressure is applied to the external urethral orifice and the pelvic urethra has created a closed system.Sudden release of digital pressure at the external urethral orifice and subsequent movement of fluid and calculus towards the external urethral orifice.4.Sudden release of digital pressure at the pelvic urethra and subsequent movement of fluid and calculus towards the urinary bladder.References1.Gahring D R. Surgical management of canine cystic and urethral calculi. In: Current Techniques in Small Animal Surgery, Bojrab M J (ed.) second edition, Lea & Febiger 1983 pp.312 - 317Surgical management of urethral obstruction in the dogURETHROSTOMYUrethrostomy is the creation of a permanent new urethral orifice. There are three locations for a urethrostomy in the dog:-a)Pre-scrotal:Just caudal to the os penis. This site permits the surgeon to perform the operation without castrating the animal, but urine scalding of the scrotum seems to be a common problem with this location.Scrotal:Where the scrotum is situated. This is the most desirable location if castration is not objectionable. The urethra at the scrotum is relatively large in diameter and superficial in location. It is also quite distensable in the scrotal area. The urethra is surrounded by minimal cavernous tissue (corpus spongiosum), thus making haemorrhage less a problem than with perineal urethrostomy. Urine expelled from the scrotal urethrostomy is directed away from the inguinal skin; urine burning of the skin is therefore not as problematic in this instance.Perineal:The perineal region is by far the least desirable, both because of urine leakage and scalding dermatitis of the perineal skin and scrotum. It is also difficult to suture the deep laying urethra to the skin in the area and wound dehiscence can be a problem in some instances.Indications for a urethrostomy:1.Recurrent calculus formation that cannot adequately be prevented by medical or dietary therapy.2.Traumatic injuries of the os penis or the penile urethra.3.Strictures in the penile urethra that resulted from previous urethrotomy incisions.4.In animals where medical management may be harmful.5.In animals that are not going to be used for breeding purposes.URINE DIVERSIONCalculi that become lodged in the proximal urethra cannot be retrieved from a prescrotal urethrotomy. Catheterization and flushing of the urethra alternately from a cystotomy incision and a pre-scrotal urethrotomy or a scrotal urethrostomy, will usually dislodge the calculi without the necessity for a perineal urethrotomy.Urine spillage and scalding are worse with a perineal urethrotomy than with a pre-scrotal urethrotomy or a scrotal urethrostomy in the dog.If a uraemic patient with a proximal urethral obstruction cannot be anaesthetised safely for a cystotomy operation, a temporary pre-pubic tube cystostomy can be performed to restore urine outflow for a short period. A local anaesthetic can be injected into the skin and abdominal muscles and be combined with a narcotic analgesic.Prescrotal urethrotomy:The most frequent site of urethral obstruction in the male dog is the caudal end of the os penis.The prescrotal urethrotomy procedure enables removal of the calculi and placement of a catheter into the bladder.Different sites for urethrotomies are prescrotal, and perineal. A local anaesthetic (2% Lignocaine) can be injected into the skin, retractor penis muscle and urethral mucosa with a 22-gauge needle. In the more excitable dog, general anaesthesia is preferred after the animal has been stabilised.Actual procedure is not required - rather concentrate on the following:reasons for choosing this sitewhat stage should surgery be performedprinciples of urethral surgeryafter careprognosis and complicationsThe dog is placed in dorsal recumbency and the ventral abdomen and preputium clipped and scrubbed for surgery. A sterile polyvinyl urinary catheter is passed into the penile urethra to the level of the obstruction.A 3 to 5 cm long ventral midline skin incision is made in the preputium just caudal to the os penis over the catheter and the calculi. This incision is between the os penis and the scrotum.The subcutaneous tissue is dissected to expose the retractor penis muscle. This muscle is bluntly elevated from the corpus spongiosum urethrae and retracted to one side. (See the figure on the next page).With the urethral catheter in place, the corpus spongiosum urethrae that surrounds the urethra, is incised on its exact midline to the urethral lumen with a No. 15 scalpel blade. Iris scissors can be used to extend the incision in the urethra. The penis must be stabilised between the thumb and index finger so as not to deviate from the midline. This incision is 2,0 to 2,5 cm in length.The urethral calculi are gently flushed out or carefully removed with a smooth forceps. The calculi are saved for diffraction analysis of the mineral contents and radiographs are taken to rule out any remaining cystic calculi. The urethrotomy wound is closed primarily with the catheter used as a stent inside the urethra. Simple interrupted 5/0 or 6/0 PDS sutures are used for closure to prevent haemorrhage or urine accumulation in the subcutaneous tissues. It increases operative time, however, and must be done carefully to prevent stricture formation.Prescrotal urethrotomy - behind the os penisa. Urethra is incised, exposing the catheter within itb. Urethra is closed with simple interrupted sutures. Fascia and skin have been partly closed.The surgeon should place an indwelling catheter to prevent the sutures from encroaching on the urethral mucosa and diminishing the diameter of the urethral lumen. Handling the urethral mucosa with thumb forceps is avoided. The suture material should not penetrate the urethral mucosa, because it may create avenues for scar tissue formation. Sutures are pre-placed in the urethral mucosa 1 to 1,5 mm from the edge and 2 mm apart, and then are tied. It is best to leave a small separation between the incised edges of the urethral mucosa and to allow the mucosal epithelium to spread along the granulation base to cover the defect. The skin edges of the preputium are apposed with simple interrupted monofilament 4/0 nylon sutures.The urethrotomy wound can also be left open to heal by second intention, depending on the condition of the urethral mucosa. If the urethral mucosa is necrotic or badly damaged by the calculi or the catheterization procedure, then it should rather be left open to heal by second intention. In wounds healing by second intention, sealing of the urethrotomy site and urination through the terminal urethra occurs within 2 to 13 days.NB:In some instances where the urethral mucosa is badly damaged, the tunica albuginea of the penis is closed over a stenting urethral catheter that bridges the urethrotomy site. The catheter does not enter the bladder and is sutured distally to the abdominal skin to maintain this position for 3 to 5 days. A bucket over the head or Elizabethian collar should be placed around the dog's neck to prevent premature removal of this catheter.Conversely, the use of small-diameter indwelling catheters has been shown to be beneficial to divert urine away from the incision, and to promote healing in urethral anastomosis. It is preferred to use a soft, thin indwelling catheter connected to a closed collecting system for a maximum of 4 days after surgery.Very controversial - rather make use of a pre-pubic catheter to divert the urine away from the surgical site!Complications associated with pre-scrotal urethrotomy in the dog:1.Stricture formation can frequently occur at the surgical site due to poor tissue apposition and mucosal damage with instruments.2.Persistent haemorrhage may be expected if the incision deviates from the midline and penetrates the corpus cavernosum penis, or when the urethrotomy incision is not sutured closed.3.When the incision is not sutured closed, oedema and subcutaneous urine leakage can lead to skin scald and dermatitis. This is a common problem encountered with perineal urethrotomies.4.Urine leakage from the urethrotomy wound can also lead to fistula formation. 5.Inflammation of the skin and subcutaneous bruising may sometimes be seen after primary closure in some dogs. First intention healing of the urethra can be expected with primary closure.6.If a wide diameter catheter is left indwelling as a stent and the urethra is sutured closed over it, then this catheter creates irritation, which stimulates inflammation and increases the risk of disruption of the suture line.7.Urinary tract infections can occur after surgery, especially if the dog has been repeatedly catheterised or if an indwelling catheter has been used for longer than 4 days.NB:All perineal urethrotomies should rather be sutured closed, however, because if it is left open, scalding of the perineal skin and scrotal skin may pose a severe problem.Surgical technique for scrotal urethrostomy:The dog is anaesthetised and placed in dorsal recumbency. The scrotum is shaved with an electric clipper and prepared for surgery. A urinary catheter is placed aseptically into the urethra.The base of the scrotum is incised with a slightly elliptical incision. The tunica dartos muscle is severed and the piece of scrotal skin is discarded.The testes are then exposed and the dog is castrated.The retractor penis muscle is now exposed and bluntly dissected from the corpus spongiosum urethrae and retracted laterally to one side.If the urinary catheter can be advanced into the urethra, it will help a lot to identify the urethra.The urethra is incised precisely on its midline to the lumen over the catheter with a No. 15 scalpel blade. The wound in the urethra should be 2,5 to 3,0 cm long.The urethral mucosa is sutured directly to the scrotal skin by placing four "corner" sutures at 45° angles. The lateral edges are then sequently sutured with the corpus spongiosum urethrae apposed to the skin. Use 4/0 or 5/0 Vicryl or Dexon suture material. Simple continuous 5/0 Vicryl sutures are currently used.The scrotal skin is resected if necessary and it is apposed as needed to create a tensionless, cosmetic closure. Any tension on the wound edges leads to tearing of the tissue and subsequent excessive scar tissue formation.If the skin incision extends caudal or cranial to the urethral incision, the skin is apposed with simple interrupted 4/0 nylon sutures.It is sometimes necessary to perform a cystotomy as well, to remove large calculi that may still be lodged into the urinary bladder. This operation can be done directly after the scrotal or pre-scrotal urethrostomy has been completed, or a day or so after the patient has been stabilised from the initial hyperkalaemic metabolic acidosis and azotaemia.The bladder can be flushed with Ringer's lactate solution and urinary tract infection prevented with a suitable broad spectrum antibiotic. Following surgical removal of cystic calculi in dogs by cystotomy, the rate of recurrence is as high as 25% to 30%.Post-operative management after scrotal urethrostomy in the dogLicking of the urethrostomy wound and self-mutilation can be prevented by using an Elizabethan collar or a bucked over the patient's head.The urethrostomy wound has to be covered with soft petroleum jelly (Vaseline?) three times per day for the first 5 days after the operation.Broad-spectrum antibiotics should be given for 3 days.Haemorrhage will frequently occur during the first three to five post-operative days when the dog urinates or if it becomes exited. This problem may be controlled with tranquilization (Acetyl Promazine? (BID) as this bleeding may sometimes last for up to 10 to 14 days!Add more salt to the dog's diet to increase the animal's water intake to stimulate diuresis and to urodynamically "flush out" bacteria that might still be lodged inside the urinary tract.Urinalysis and urine cultures should be checked at 2 to 4 week intervals.Analysis of the urinary calculi is essential to treat the condition rationally and to prescribe the correct calculolytic diet for the prevention of this disease. Approximately two out of three cases with urinary calculi are culture positive, and approximately one out of three cases recur with new calculi formation!The kidneys will have an obligatory water diuresis for several days following relief of the urethral obstruction. If a hypokalaemia develops, additional potassium may be added to the Ringer's lactate solution or oral elixirs of potassium can be administered.CYSTOTOMYAfter the anaesthetised animal has been prepared for an aseptic celiotomy procedure, it is placed in dorsal recumbency.Intravenous fluid therapy should be maintained during the surgical procedure, as well as post-operatively. This is done to evaluate urine output. (Normal 1 to 2 ml/kg/24 hour period).A caudal midline abdominal incision is made from the umbilicus to the cranial edge of the pubis in the bitch. In the male dog, a ventral midline abdominal skin incision is made from the umbilicus and is extended caudally along the lateral side of the preputium to the cranial edge of the pubis. The caudal superficial epigastric artery and vein branches to the preputium are ligated and transected. The cranial preputial muscle and superficial abdominal fascia are incised on the one side, and the preputium reflected laterally, so that the incision through the linea alba can be continued to the cranial edge of the pubis.The urinary bladder is exteriorised and packed off with moistened abdominal swabs. Stay sutures are used in the apex of the bladder to facilitate manipulation and handling of the organ.The cystotomy incision is made on the ventral aspect of the bladder wall between major blood vessels. The bladder wall is handled by stay sutures only, otherwise soft tissue trauma can be exerted if instruments are used on these delicate tissues.After the bladder is opened, urine is removed with suction, and samples for bacterial cultures can be taken directly from the bladder mucosa.Cystic calculi are removed with a forceps or scooped out with a sterile, smooth-edged teaspoon. They are saved for chemical analysis.The trigone area is palpated for calculi. Any remaining calculi that are maintained in the neck of the bladder or urethra can be dislodged by flushing the urethra alternately from the bladder and from the urethral opening. A catheter is passed through the urethral opening into the urethra and saline is flushed through the urethra as the catheter is advanced. Any calculi that are back flushed into the bladder are retrieved.The bladder wall is inspected for any abnormalities. A vesico-urachal diverticulum appears to be a predisposing factor for recurrent urinary tract infection.The bladder is flushed out with Ringer's lactate solution and the cystotomy incision closed with simple interrupted or a single row of continuous absorbable sutures (4/0 or 5/0 PDS, Vicryl, Dexon, or Monocryl). When multi-filament materials like Vicryl or Dexon are used, one should try not to penetrate the bladder mucosa in cases with chronic cystitis, as these materials may provide a nidus for calculus formation.The linea alba is closed with simple interrupted monofilament 2/0 nylon or Prolene sutures. The cranial preputial muscle should be re-apposed if it is well developed and the skin is closed with simple interrupted 4/0 monofilament nylon sutures.Removal of urinary calculi from the bladder and urethraA- Urethral calculi can be flushed proximally into the bladder from a urethrotomy or urethrostomy B-Calculi can also be flushed from the cystotomy out through a urethrotomy. Any calculi dislodged into the bladder are removed through the cystotomy incision.Perineal urethrostomy in the dogThe urethra in the perineal area is surrounded by cavernous tissue and is located very deeply in this area. Deep dissection is therefore necessary to exteriorise the urethra and profuse haemorrhage may be encountered. This occurs because the corpus spongiosum urethrae is relatively large in this area.The fibres of the bulbospongiosus muscles are split longitudinally on the midline at the median raphae, and the urethra is incised on its midline over a pre-placed catheter. The length of the incision into the urethra should be long enough to create a stoma of at least 1,5 to 2,0 cm in length.A row of sutures is placed between the tunica albuginea of the penis and the subcutis to minimize the tension on the urethral mucosa-to-skin plications associated with perineal urethrostomy in the dogMobilisation of the urethra to the skin edge can result in excessive tension on the primary suture line, thereby producing the potential for wound dehiscence.Urine can accumulate in the subcutaneous tissue and produce a chemical cellulitis that can lead to infection and abscessation of the local tissues.Urine is frequently directed to the scrotum and severe skin scalding dermatitis may necessitate castration at a later stage.Ascending bacterial cystitis has been reported as a complication after perineal urethrostomy in the dog. Periodic urine analysis should therefore be obtained by means of cystocentesis to monitor for cystitis.URETHRAL TRAUMA AND PRINCIPLES OF URETHRAL SURGERYAnatomy of the canine urethraThe urethra of the male dog is divided into three portions:-The most proximal segment is the prostatic urethraThe second segment is the membranous urethra, from the prostate gland to the bulb of the penis.The third segment is the cavernous urethra, and extends from the bulb to the tip of the penis.The urethra in female dogs is much shorter and wider than that in males and is not divided into segments.Causes of urethral trauma in male dogs:Dog bites and projectiles such as bullets and arrows can cause penetrating injury to the urethra.Motor vehicle accidents account for some injuries.Urethral calculi that become lodged behind the os penis.Poor technique during diagnostic or therapeutic catheterization procedures can cause iatrogenic urethral trauma.Pelvic fractures where the pubic bone is involved can cause damage to the prostatic or membranous portion of the urethra.Poor intra-operative technique can cause iatrogenic urethral trauma.Urethral prolapse in Bulldogs.Clinical signs of urethral trauma:Male dogs are most frequently diagnosed with urethral trauma, especially in cases with pelvic fractures. Penetrating perineal wounds or caudal abdominal bruising should also lead to an evaluation of the urethra.Clinical signs associated with urethral laceration include:haematuria at the beginning of urination, dysuria, or anuria;depression and anorexia;perineal swelling, bruising, or fistula formation;a rupture at the vesico-urethral junction can allow urine to extravasate into the peritoneal cavity and cause abdominal distention similar to a ruptured urinary bladder.Diagnosis:The preferred diagnostic test is the positive-contrast retrograde urethrogram. If there is total pelvic urethral transection, contrast material will extravasate into the peri-urethral tissues and will not bypass beyond the defect. With a laceration into the urethra, contrast material can still accumulate in the urethra proximal to the traumatized area.Management and treatment:Selection of appropriate treatment for urethral trauma is based on the extent, cause, and anatomic location of the injury.An urethral abrasion, as can occur with repeated catheterization, can be treated non-surgically. The ideal management is to remove the indwelling catheter. If cessation of catheterization in impossible, a small gauge catheter, (one that will allow peri-catheter drainage of exudate from the traumatized urethra), should preferably be used.If the urethra is contused, but still intact, non-surgical management is again indicated. Monitoring of urination and hot packing (if the area is accessible) can be performed. The unfortunate problem is, however, that urethral contusion can later develop into a fistula.NB:A very small laceration may heal spontaneously if the urethra is stented with a small-gauge indwelling catheter or with a soft neonatal feeding tube.Most partial urethral lacerations and all total urethral transections, however, require surgical correction.Surgical exposure depends on the location of the laceration, and is based on the positive-contrast urethrogram findings. A catheter is passed to the level of the defect to help identify the urethra and also to act as a stent.After transection of the urethra, the severed urethral ends retract into the peri-urethral tissue. This retraction is a function of the contraction of the muscular layer of the urethra. If the urethra is not closed surgically, the resultant gap fills with fibrous tissue and can form a stenotic area later on.Primary closure of a complete urethral transection, rather than only stenting it with an indwelling catheter, reduces the incidence of post-traumatic stricture formation.Researchers also recommend that urethrotomy incisions should not be closed primarily when mucosal and corpus spongiosum urethrae damage precludes adequate approximation. It is believed that closure of these wounds could increase stricture formation. Urethral mucosa can regenerate if a longitudinal strip of urethra remains intact. A strip of autogenous fascia latae can also be used to span a gap across a damaged urethra if the two ends cannot be anastomosed. An indwelling catheter should be used to act as a stent until the uro-epithelium has grown across the gap. It may take 10 to14 days before the indwelling catheter can be removed without complications of stricture formation.In a dog with a fractured os penis, a urethral catheter is passed if possible. Urine is diverted through the catheter during the initial healing of the fracture, and obstruction from swelling or trauma is alleviated.If a catheter cannot be passed in a case with fracture of the os penis, repair of the fracture is attempted (if it is a large breed dog) and a prepubic cystostomy Foley’s catheter is used to divert the urine away from the traumatized urethra while it heals. Permanent scrotal urethrostomy is only performed in dogs in which repair is impossible or in which an urethral stricture has occurred.Traumatic injuries to the intrapelvic or membranous urethra can be approached surgically through a ventral incision extending to the pubis. Further exposure might require splitting of the pubic symphysis or reflection of the cranial portion of the pubic bone.The intrapelvic urethra might be anastomosed over an urethral catheter after débriding the ends. Copious lavage and drainage of the area should be considered. Prostatectomy is indicated if trauma to the prostatic urethra is extensive. A prepubic cystostomy Foley's catheter should be placed to divert the urine away from the anastomotic site.NB:A potential complication of intrapelvic urethral trauma is urinary incontinence from the primary injury or from surgical trauma! Atraumatic technique and careful dissection is imperative, because identification of the blood vessels and nerves can be extremely difficult in this area.Principles of urethral surgery:Urine flow should be diverted by either by using an indwelling urethral catheter or by a cystostomy catheter.The prepubic cystostomy catheter should be fixed to the skin and attached to a closed drainage system. It has been advocated to wait 5 to 7 days before this catheter can be removed again.Gentle manipulation of tissues is an important principle of urethral surgery. Atraumatic tissue forceps should be handled judiciously. Iatrogenic trauma in addition to trauma already sustained, increases the possibility of fibrous tissue formation and subsequent stenosis.The severed ends of total urethral transections should be débrided for 1 to 2 mm, because the ends retract back into the peri-urethral tissues.An anastomosis of the traumatized urethra should have minimal tension, because too much tension at this site will separate the urethral ends and cause fibrous tissue stricture formation. Thin, absorbable, atraumatic synthetic suture material such as 4/0 or 5/0 PDS is recommended.Depending on the cause of trauma and the amount of urine extravasation, copious lavage of the injured area can improve the environment for healing.Drains are indicated in contaminated wounds and when excessive tissue necrosis is anticipated. It is essential to place the drains close to the anastomosis, but not in contact with it. If the drain touches the suture line, healing will be delayed and it can lead to subsequent fistula formation.Catheter management:If an indwelling urethral catheter is used, it should be fixed to the tail in female dogs or to the abdomen in male dogs to help prevent premature removal by the patient. A bucket or Elizabethan collar over the head will also assist in preventing the animal from chewing and damaging the catheter.A thin, soft Foley's catheter is usually used in female dogs, because of its short length. The Foley's bulb should be inflated and the catheter fixed to the tail with adhesive tape. Small-gauge urethral catheters are used in male dogs to allow peri-catheter drainage of exudate from a traumatized urethra. Too large a catheter can promote irritation of the urethral mucosa and subsequent stricture formation.Prepubic cystostomy catheters may be used simultaneously with urethral catheters. Most urine will flow through the cystostomy catheter. A small-gauge indwelling urethral catheter can be used to splint the primary repair or the urethral defect until healing occurs.All urinary catheters should be maintained as a closed system. This incorporates the catheter, the collection tubing, and the collection bag or bottle, using strict aseptic technique.The duration an indwelling urinary catheter is needed is still controversal. One source asserts that catheters should be maintained for 3 to 5 days in sutured defects, and as long as 21 days with non-sutured ones.A recent prospective study evaluating urinary tract infections from indwelling urinary catheters in dogs and cats demonstrated that infections increased with catheterization for longer than four days. (52% of the animals had positive urine cultures after 4 days (mean) of catheterization, even with a closed system!).The prophylactic use of antibiotics in the catheterized animal is also not recommended, as this leads to persistent infections with antibiotic-resistant organisms. It is preferable to first do a urinalysis and to perform bacterial culturing and antibiogram testing of the tip of the catheter, as well as the urine when the catheter is removed.NB:If a urinary tract infection is present at the time of catheter placement, antibiotic therapy should be based on known antibiotic susceptibility.The risk of inducing infection is cumulative for repeated intermittent catheterizations. If catheterization is required for a short time (<3 days), then an indwelling catheter is recommended.ECTOPIC URETERSUreteral ectopia occurs in both dogs and cats and results from abnormal differentiation of the metanephric duct system. The metanephric ducts normally become the ureters and terminate in the vesico-ureteral area of the bladder to form the trigone of the urinary bladder. Ectopic ureters may occur uni- or bilaterally and may terminate in the neck of the bladder, urethra, uterus, vagina of the female, or in the ductus deferens of the male animal.Ureteral ectopia.Numbers indicate the areas into which the ureters may exit:1-normally, into the bladder;2-into body of uterus;3-into neck of bladder;4-into urethra;5-into vaginaEctopic ureters occur most commonly in the bitch, but both male and female dogs and cats may be affected. In nearly 50% of reported cases in dogs, a hydroureter was present. Other abnormalities observed include cystic and renal agenesis or hypoplasia, uretrocoele, ureteral duplication, and branching of the terminal ureter.Clinical signsBreeds most frequently affected are the Siberian husky, Poodle, Labrador, Scottish terrier and Newfoundland.1.Urinary incontinence since birth is the most frequent clinical sign observed especially in female dogs. Sometimes incontinence is first noticed at weaning.2.In male dogs, urinary incontinence is first noticed in adult animals between 10 and 12 months of age.3.Dribbling of urine is constant and the peri-vulvar hair remains wet and discoloured with a bad odour. The perineal skin may also be excoriated.4.Affected bitches often urinate normally despite the constant dribbling, because urine can reflux retrograde into the bladder if the ectopic ureter drains into the neck of the bladder, or into the urethra proximal to the external urethral sphincter.5.Affected animals are usually healthy and exhibit no other clinical signs, although cystitis or pyelonephritis can easily develop if urinary tract infection is present.Other possible causes for urinary incontinence are the following:behavioural disorders (excitement in puppies)neurogenic disorders (LMN lesion distal to L5 Overdistended bladder with sphincter tone)cystitis and / or urethritisbladder sphincter incompetence in the bitchpartial urethral obstruction by urinary calculicystic diverticulum with frequent urination and incontinencecongenital abnormalities - urachal diverticulum in the bladder apexhormonal imbalance following ovario-hysterectomyneoplasia of the neck of the bladderDiagnosis of ectopic ureter in the bitch1.A definitive diagnosis is best achieved by positive contrast excretory urography (EU). Localisation of the exact site of ureteral termination can sometimes be very difficult; however, the finding of a dilated terminal ureter or a hydroureter with a hydronephrosis in an incontinent juvenile patient is highly suggestive of an ectopic ureter. Fluoroscopy is also very helpful to aid in the diagnosis of a branching ureter. 2.Retrograde vaginocystogram may also enable location of an ectopic ureteral orifice.3.Abnormalities involving the urethra can be identified by a retrograde positive contrast urethrogram in the bitch. A congenitally small bladder is usually evident on a cystogram.4.Exploratory celiotomy - ectopic ureters frequently dilate (hydro-ureter) in response to an increased resistance to urine outflow at the ureteral exit. Even when the orifice is ectopic, the ureter often enters the bladder musculature normally at the trigone and may or may not reappear and be visible along the urethra.5.An exploratory celiotomy combined ventral cystotomy and urethrotomy to determine the presence or absence of an anatomically correct ureteral termination in the trigone area of the bladder.Surgical treatment or correction of an ectopic ureterEffective treatment requires surgical creation of a new ureteral orifice into the bladder in the vesico-ureteral area either through transplantation or neo-ureterostomy and ligation of the ectopic distal ureter.NB: There is no medical treatment that can resolve this type of urinary incontinence.If there is a significant degree of hydro-ureter unilaterally, or a hydronephrosis with evidence of loss of renal or ureteral function in the affected side, uretero-nephrectomy is the treatment of choice.Uretero-vesicular anastomosis should be performed with unilateral ectopic ureter in which the kidney and ureter on the affected side appear normal. Uretero-vesicular anastomosis is also indicated for bilateral ectopic ureters.Very thin, synthetic absorbable suture material like 5/0 PDS should be used for the anastomosis inside the bladder, because nonabsorbable material can serve as a nidus for urinary calculus formation inside the bladder or urethra.There are two surgical methods that can be used to create a new uretero-vesicular connection:An intra-vesicular technique can be used in which a ventral cystotomy is performed first. The entrance of both ureters into the trigone should be examined first, because ectopic ureters may occur bilateral. Here the anastomosis can be done under direct visualization. The ectopic ureter is severed close to the bladder and transplanted to a new location in the bladder (see Figure below).Transplantation of an ectopic ureter into the bladderb)If the ectopic ureter enters the bladder wall normally, yet continues submucosally past the trigone. The ureter is left in place and an appropriate entrance into the bladder is created directly from the inside of the bladder over the existing, palpable ureter. With this neo-ureterostomy technique, a new stoma is created into the bladder under direct visualization, and ligation of the distal portion that runs intra-murally in the wall of the urethra.The neo-ureterostomy technique leaves the ureter in setu at its junction with the bladder wall and offers the advantage of minimal disruption of the blood supply and innervation to the ureter. The ectopic ureter's orifice is first catheterised from the urethral side and the catheter is palpated where it lies inside the lumen of the ureter. A new stoma is made in the trigone area of the bladder over the palpable catheter. The ureteral mucosa is then sutured to the bladder mucosa with 5/0 simple interrupted PDS sutures.Prognosis for ectopic ureterPost-surgical incontinence is a frequent complication and can be caused by concurrent abnormalities in the bladder sphincter mechanism. Treatment with phenylpropanolamine hydrochloride syrup (20 mg/ml) to increase the -adrenergic tone of the internal urethral sphincter can resolve some of the incontinence. Diethyl-stilboestrol has been used in the past, but nowadays synthetic estradiol (Incurin? tablets) is used with fairly good results.The prognosis for successful surgical intervention is guarded if the ectopic ureter terminates in the vagina or uterus. Regardless of the technique used for correction, the prognosis is even poorer when the ectopic ureter terminates in the urethra, because this condition is associated with a higher degree of post-surgical incontinence.Local swelling that can occur directly post-operatively from oedema and surgical trauma and permanent stricture formation from fibrous tissue at the anastomotic site at a later stage are also potential problems that may occur.Other reported surgical complications include anastomotic dehiscence, hydro-ureter, hydronephrosis, and transient loss of normal ureteric peristalsis.Branching of the terminal ureter might also cause post-surgical incontinence if the branching has not been identified pre-operatively, and / or if it occurs in the un-operated ureter.Post-operative managementStrict care must be taken to treat any urinary tract infections with appropriate antibiotics, depending on bacterial cultures and antibiogram results.Urinary tract infection was diagnosed in 64% of dogs with ectopic ureters in one study. Bacterial infections caused by Proteus, E. coli and Staph. aureus seem to be most prevalent. The source of infection may be related to reflux of urine from the vagina into the urinary bladder. In addition, vaginitis secondary to urine scalding would augment perineal contamination of the urethra.References1.Rawlings C A. Repair of ectopic ureter, In: Current Techniques in Small Animal Surgery, Bojrab M J (ed.) second edition Lea & Febiger, Philadelphia, 1983 pp. 308 - 3122.Gambardella P C, Archibald J. Ureteral ectopia, In: Canine and Feline Surgery, Archibald J and Catcott E J (eds.) First edition,Vol !, Abdomen, American Veterinary Publications, Inc. 1984 pp 386 - 405PERINEAL URETHROSTOMYPerineal urethrostomy is rarely required for emergency relief of urethral obstruction. It is occasionally recommended in cases with recurrent obstructions that do not respond to medical therapy. Perineal urethrostomy gives the best permanent relief of recurrent penile urethral obstruction in the cat.The creation of a permanent opening into the urethra is indicated for the following conditions:Removal of proteinaceous material, cellular debris, and crystals associated with the FLUTD syndrome, none of which can be retro-hydropulsed with saline;Strictures in the penile urethra resulting from one or more episodes of urethral trauma (catheterization);Recurrent mechanical urethral obstruction that is not controlled by medical or nutritional therapy.Pre-operative considerations1.Anaesthetise the cat after it has been stabilised with intravenous fluid therapy and maintain the intubated animal on 2% fluothane / 2% Isofluorane - use a semi-open system.2.Re-establishment of urine outflow while inducing the minimum amount of trauma to the distended bladder, without the risk of urinary tract infection, should receive emergency priority.3.A cystocentesis is performed after abdominal skin preparation. A thin 22 gauge needle is used to provide immediate, temporary decompression of the urinary bladder. If the animal is still dehydrated and acidotic, use a 2,5% Dextrose in 0,45% saline drip. (This drip contains no potassium and it is isotonic).4.Diuresis during the surgical procedure can be promoted with a 10% dextrose solution (iv). This solution causes an osmotic diuresis and fills the urinary bladder during the operation with no ill effects on the patient.5.Fluid administration should, however, be carefully performed in cats with compromised renal function. Many possible complications in kidney function resulting from acute, total urinary tract obstruction may occur - (See medicine notes).Surgical technique of Wilson and Harris (1971) for perineal urethrostomy in the cat (*NFEP)This technique consists of exteriorising the lumen of the pelvic urethra and suturing the urethral mucosa to the perineal skin. Care is taken to assure mucosa-to-skin apposition around the new stoma in order to avoid wound granulation, resulting in stricture of the new opening.The hair of the perineum and external genitalia is clipped with an Oster? clipper and the area is prepared for an aseptic surgical procedure.A pursestring suture is placed around the anus to eliminate any faecal contamination of the surgical field.The cat is placed in ventral recumbency with the perineum elevated at ± 30°. The tail is extended directly over the dorsal midline and is immobilised.An elliptical skin incision is made to excise the scrotum and prepuce. This manoeuvre exposes the testes in the intact male (Figure A), or a fat pad in the castrated male (Figure B).Castration should be performed at this stage in the intact male cat.The penis is reflected dorsally and laterally at approximately 45° angle, and the loose tissue surrounding the penis is dissected to the penile pelvic attachments on the ventrally situated ischial arch.The ischiocavernosus muscles covering the crus of the penis on the left- and the righthand sides, are isolated and transected where the muscles are attached to the ischium. If these muscles are incised right against their bony origins, they do not bleed so easily. (See Figure C).The penis is then directed on the dorsal midline, and the penile ligaments that attach the penis to the ventral side of the pelvic canal, is carefully cut with small scissors. (Figure D). All the ventral penile attachments to the pelvis are now ruptured by blunt digital dissection, so that the rest of the penis and pelvic urethra are freed from the pelvic floor.The penis is reflected ventrally, and the loose areolar tissue on its dorsal aspect is excised to expose the retractor penis muscle that lies dorsal to the penile urethra. (See Figure E).The retractor penis muscle is carefully removed from the dorsal aspect of the penis to expose the penile urethra. (See Figure F).As the penis is reflected ventrally, the bulbourethral glands (which may be atrophic in neutered cats), must be flush with the skin wound. If not, then the loose tissue surrounding the penis in the pelvic canal has not been sufficiently loosened by blunt digital dissection.The penile urethra is incised dorsally and longitudinally through the glans penis to the wider pelvic urethra with sharp-sharp iris or tenotomy scissors. (Figure G). The opening of the wider pelvic urethra is 4,0 mm in diameter and may be identified by a distinct feeling of cutting dense tissue. It is actually the fascia of the ischio-urethralis muscle that is felt between the jaws of the scissors.A blunt instrument such as a straight mosquito artery forceps or a yellow-tip 6 FG dog urinary catheter is now inserted through this wide opening in the pelvic urethra to make sure that the incision is adequate. The catheter is advanced into the bladder to allow free urine outflow.The dorsolateral pelvic urethra is sutured to the perineal skin with the first two sutures placed at approximately 45° angles to the midline. (Figure H). These sutures will pull the pelvic urethra caudally and widen the urethrostomy opening.Two thirds of the penile urethra is sutured to the perineal skin with simple interrupted 5/0 Vicryl sutures, approximately 2 mm apart. NB: It may be possible to suture the pelvic urethra closed if the urethral mucosa is not properly identified!The distal ? of the penis is amputated, and the last two sutures in the penile urethra are placed at 45° angles to the midline at the ventral end of the flap to widen the urethrostomy mucosal flap.Post-operative managementThe pursestring suture around the anus should be removed.The urethrostomy wound must be covered with petroleum jelly (Vaseline?) three to five times per day for the first 5 days to prevent drying out of the urethral mucosa.Broad spectrum antibiotics should be given systemically (b.i.d.) for 3 days.The litter box in the cat's cage can be filled with shredded paper or clean, washed sand to eliminate possible infection from litter sticking to the wound.Severe over-distention of the urinary bladder may cause detrusor muscle atony. Manual compression of the bladder (t.i.d.) may be necessary in some cases that cannot empty the bladder themselves. Parasympathomimetic drugs such as bethanicol chloride (Urecholine?) may also be used in combination with manual compression to stimulate the bladder wall to contract.Avoid the use of indwelling urinary catheters, as it will only induce urinary tract infections and irritate the already traumatised urethral mucosa.If the cat is anorexic or depressed, appetite can be stimulated with an injection of diazepam (Valium?) at a total dose of 2 mg (im or iv).Hyperkalaemic cats are treated with an intravenous infusion of Ringer's lactate solution at a dose rate of 5% to 8% of the body mass for 2 to 4 plications associated with perineal urethrostomy in catsPost-operative stricture can occur if the penile urethra was not incised up to the wider pelvic urethra.Strictures develop if there was incomplete dissection of the penile pelvic attachments, so that excessive tension on the skin-to-mucosa sutures cause either wound dehiscence or abundant fibrous tissue formation around the urethrostomy.Laceration of the pelvic urethra during catheterization (before the surgical procedure), can cause urine to infiltrate underneath the skin of the caudal thighs or into the peritoneal cavity. Severe cellulitis, necrosis and sloughing of the caudal perineal skin or skin of the thigh may occur.In long-haired Persian cats, the perineal hair mats over the urethrostomy site and may obstruct urine outflow.The incidence of urinary tract infection has been reported to be much higher in operated cats presented with FLUTD syndrome. This occurs due to impairment of the natural host defence mechanisms. Perineal urethrostomy alters the urethral meatus and sacrifices a portion of the high pressure zone in the penile urethra that serves as a mechanical barrier against ascending bacterial infections. Intrinsic defences that are compromised can include surface antibacterial activity, functional microplicae, trapping mechanisms, hormonal effects, local secretions and immune or inflammatory responses.Detrusor muscle areflexia may occur in a severely distended bladder, with subsequent bladder paralysis. Affected cats may develop post-operative azotaemia if these atonic bladders are not manually expressed three times daily. This condition can sometimes last for 4 to 6 days and retention cystitis may also develop.The use of too thick suture material or sutures that are pulled too tight can cause irritation of the wound. This may lead to consistent licking and self-mutilation with wound dehiscence after a few days. Uraemia, associated with FLUTD syndrome, may cause depression of the bone marrow and a non-regenerative anaemia may develop in certain instances.PATIENT MONITORINGLong-term dietary therapy and urinary acidification is recommended. Owner education of the condition and clinical signs is of utmost importance.References1.Allen DG 1991 Small Animal Medicine pp 647-6552.Ettinger SJ Feldman EC 2000. Textbook of Veterinary Internal Medicine3.Lawler D 1988 New concepts of feline lower urinary tract disease. Compendium on Continuing Education for the Practising Veterinarian 10:1015-10284.Hyde D 1987 Dietary dissolution of urinary calculi in cats. Compendium on Continuing Education for the Practising Veterinarian 9:141-1455.Glennon J, Orsher R 1986 Urachal diverticulum in a cat with signs of lower urinary tract infection. Compendium on Continuing Education for the Practising Veterinarian 8:310-3126.Kirk R 1989 Current Veterinary therapy X pp 1209-12137.Kirk R 1986 Current Veterinary therapy IX pp 1159-1163, 1196-12068.Wilson GP, Kusba JK 1983 Perineal urethrostomy in the cat, In: Current Techniques in Small Animal Surgery, Bojrab MJ (ed.), Lea & Febiger, Philadelphia. pp 325-3319.Osborne CA, Caywood DD, Johnston GR 1991 Perineal urethrostomy versus dietary management in prevention of recurrent lower urinary tract disease. Journal of Small Animal Practice 32:296-30510.Griffi DW, Gregory CR 1992 Prevalence of bacterial urinary tract infection after perineal urethrostomy in cats. Journal of the American Veterinary Medical Association 200:681-68411.Fooshee SK, Holland M, Cooper RC 1992 Persistent haematuria secondary to a lower urinary tract foreign body in a cat. Journal of the American Animal Hospital Association 28:167-169 SURGERY OF THE PROSTATE GLANDProstatic disease is a common clinical entity in older, intact male dogs, and is usually associated with symptoms of chronic disease. The symptoms in dogs suffering from the one or other form of prostatic disease can include the following:Difficult urination (stranguria)HaematuriaRetention cystitisRecurrent constipation and difficulty in locomotion, and eventually the development of a perineal hernia.Prostatic biopsy:Fine needle aspiration, rectally or transabdominally for bacterial culture or cytology, may differentiate abscess formation from neoplasia. A blind needle biopsy can be performed on old castrated dogs with solid prostate glands in a fixed position due to cancer. This technique is dangerous in that a prostatic abscess or cyst can be ruptured with the needle, and an iatrogenic peritonitis may then be produced.Laparotomy - surgical wedge resection biopsy is performed for histopathology and bacterial culturing. Once the abdomen has been opened, the fat overlying the ventral aspect of the prostate gland is carefully scraped away with a swab so that the gland can be visually inspected. An appropriate site in each lobe is selected for the wedge shaped biopsy. The capsule can now be sutured closed again to avoid brisk haemorrhage within the abdominal cavity.PROSTATIC CONDITIONS THAT NEED SURGICAL THERAPYBenign prostatic hyperplasia (BPH) occurs in mature, intact male dogs in response to estrogen and/or androgen stimulation. Although clinical signs may be minor (mild discomfort, haematuria, haemospermia, urethral discharge), the condition is progressive and surgical treatment is advised. Castration is the preferred treatment, but hormonal therapy may be attempted in the valuable breeding dog.Squamous metaplasia is an inflammatory change that results from estrogen stimulation (exogenous therapy or from a Sertoli cell tumour) in the intact dog. Large numbers of squamous epithelial cells are present in the centrifuged prostatic fluid samples.Prostatic abscess may be small and located in one of the lobes of a slightly enlarged prostate gland, or it may be a fairly large abscess in a greatly enlarged gland. Initially, prostatic abscesses are treated with antibiotics, but usually require proper surgical drainage.Firstly the prostate gland is packed off with moistened abdominal swabs to prevent any contamination of the abdominal organs. The abscess is opened with a scalpel blade and all puss is sucked out of the abscess with a suction pump. Any loculations inside the abscess cavity are broken down with the index finger. The abscess cavity should be flushed out thoroughly with Ringer's lactate solution. A stab incision is then made in the other side of the capsule and the omentum is pulled through the abscess cavity and through this new opening in the capsule. The free end of the omentum is then sutured onto the rest of the omentum to form a loupe. This prostatic parenchymal omentelization technique provides leukocytes to the abscess cavity and also drains exudate away from the prostate gland. No additional drains are required to excess the abdominal cavity and the post-operative complication rate with this technique is less that when compared with the conventional placement of Penrose drains.Prostatic adenocarcinoma is androgen dependent and may be reduced in size by castration or by treatment with megestrol acetate (MA), Thus providing temporary relief for the patient. Total transurethral prostatectomy is a difficult procedure, but may be attempted as a final solution. Most prostatic tumours have already metastasized to the lungs or other organs by the time a diagnosis is made.Cystic hyperplasia - With time, BPH alters the prostatic parenchyma, which results in cystic hyperplasia. These small multiple cysts contain blood or a serosanguinous fluid and constantly discharge into the bladder and urethra. Hormonal therapy and castration are indicated for treatment of cystic hyperplasia. This condition can be differentiated from non-inflammatory prostatic retention cysts by evidence of inflammation (neutrophils) in the prostatic fluid.Paraprostatic and prostatic retention cysts can enlarge to the point that surgical drainage is required. The cyst wall may also become calcified in some instances. These cysts usually contain a brown coloured fluid, sometimes up to 500 ml or more.Surgical approach to the prostate gland * (NFEP)Dogs needing prostatic surgery often have chronic urinary tract disease, including interstitial nephritis with elevated serum creatinine levels. Therefore, pre-operative fluid therapy is needed.A caudal laparotomy is performed after placement of a sterile, medium-sized, well-lubricated urinary catheter. The skin incision is made from cranial to the umbilicus in the midline, caudally to the preputium, and is extended to the pubis lateral to the preputium. The Vena epigastrica caudalis superficialis lies across the incision and is divided between ligatures. The penis and preputium are retracted laterally so that the abdomen can be entered via a midline incision from the umbilicus to the pubis.The abdominal muscles are kept open with a Balfour or other wound retractor and moistened laparotomy swabs are used to isolate the bladder and prostate gland from the other abdominal organs.It is usually possible to approach the prostate gland by simply retracting the bladder cranially. If the prostate is much enlarged or partially located inside the pelvic canal, then the cranial portion of the pubis can be reflected dorsally following osteotomy to reach the caudal part of the prostate gland.A midline dissection is necessary through the ventral peri-prostatic fat to adequately expose the gland. The complex neuro-vascular network bilaterally on the dorso-lateral surface of the gland (at the 10 o'clock and 2 o'clock positions), should be avoided. The following vital structures are embedded into this neuro-vascular network:* NFEPNn. pelvini (parasympathetic innervation)Nn. hypogastricus (sympathetic innervation)A. prostatica → A. vesica caudalis→ A. rectalis medialis→ A. ducti deferenti→ Ramus urethralisNn. pudendus - innervates the Mm. urethralis (external urethral spincter)Local resection of the prostate gland may be performed for the treatment of a localized prostatic abscess, a small cyst, a para-prostatic cyst and for wedge resection biopsy.Marsupialization:This is a drainage technique used for a prostatic abscess that is fairly large and well encapsulated, as well as for a large prostatic or para-prostatic cyst. The prerequisities for marsupialization of the prostate is that the cyst or abscess should be in such a position that it can be mobilized to the ventral abdominal wall, and the capsule should be thick enough to be capable of holding sutures.The circumference of the cyst wall is sutured to the external rectus fascia, the internal fascia and the peritoneum using a simple continuous suture pattern with 2/0 Vicryl. The margin of the cyst wall is then lanced, the cyst is drained and the cyst cavity flushed out with Ringers lactate solution. The margin of the cyst wall is then sutured directly to the skin with simple interrupted 2/0 monofilament nylon sutures.The ventral opening on the one side of the preputium is left open and allowed to drain for 4 to 8 weeks. It will eventually become smaller and close up by itself after the nylon sutures have been removed.Drainage of a prostatic abscess:This technique should be considered when a prostatic abscess or multiple prostatic abscesses are either too small or too numerous to allow marsupialization.The prostate gland is again exposed along its ventral midline and the bladder retracted cranially with stay sutures. Prostatic fat is gently dissected away along the ventral midline of the gland, between the two lobes to expose the entire gland. The fat should not be excised or traumatized because small autonomic nerves (Nn. Pelvini) are present in the peritoneum covering the fat.The prostatic abscess is located, and moistened laparotomy swabs are placed around the area to confine it and also to collect any leakage of exudate. The abscess is first aspirated with a thick needle and specimens thereof are taken for bacterial culturing and antibiogram. The abscess area is then lanced and drained by means of a stab incision ventrally and emptied with suction. (See figures on the next page).The initial incision into the prostate is enlarged to permit digital entry into the abscess cavity for further exploration of the glandular tissue, fibrous adhesions and any nearby loculi that may be present.The abscess is then flushed repeatedly with luke warm Ringers lactate solution or a 10% Betadine? solution. It is important that flushing should be vigorous, with a large volume of the solution. This flushing procedure should be repeated in other abscessed areas as well.Finally, the abscess capsule is incised dorsally as well to allow two to four Penrose drains (2 to 4 cm in diameter) to be inserted into the abscess cavity from ventral to dorsal. These drains are sutured in place dorsally with 4/0 plain catgut through the glandular capsule. The drains are then exteriorized to one side of the abdomen through a single ventral opening. Two to four additional Penrose drains are placed into the peritoneal cavity near the abscess area and are exteriorized through another ventral incision in the opposite side of the abdomen or preputium.The entire area is thoroughly flushed again and the ventral midline is closed with 2/0 monofilament nylon in an interrupted suture pattern. The skin incision for the laparotomy is closed routinely with 4/0 monofilament nylon.Castration is performed as a routine therapeutic adjunct. Vigorous antibiotic therapy is given systemically, based on the culture and antibiogram test results. The intra-prostatic drains are removed firstly in 3 to 5 days after the operation, and the peritoneal drains are removed 2 days later.This drainage technique has the advantage of allowing the veterinary surgeon to deal with prostatic abscessation quickly and to avoid the lengthy and difficult dissections associated with a total transurethral prostatectomy. Contamination of the peritoneal cavity is inevitable, but can be managed with vigorous, liberal flushing of the peritoneal cavity with luke warm Ringers lactate solution, followed by careful suction and daily changing of the wound dressings. NBThe prostatic parenchymal omentelization technique has, however, taken over the abdominal drainage technique and is currently the preferred technique to use for the treatment of well encapsulated prostatic abscesses and cysts.Drainage of Prostatic abscessA-Cranial traction of the urinary bladder with stay sutures and midline incision with reflection of the ventral prostatic fat to provide visualization of the diseased prostate gland.B-A stab incision is made into the immobilized prostate gland and the abscess cavity is drained using surgical suction.C-Penrose drains are installed into the glandular cavity and exit through the ventral abdominal cavity.Subtotal prostatectomy in the dogA subtotal, intracapsular prostatectomy is indicated when the risk of total prostatectomy is not warranted, or for the removal of localized prostatic infection. This procedure may also be indicated for the removal of a fairly large portion of the infected gland that has proved to be untreatable by other means. Subtotal prostatectomy is a shorter operation with fewer potential post-operative complications than a total prostatectomy. The major disadvantage of this procedure, however, is that neither the entire gland, nor any diseased portion of the prostatic urethra is removed. This procedure can therefore not be used for the treatment of neoplastic conditions of the prostate gland.The prostate gland is again approached along its ventral midline while cranial traction is applied on the urinary bladder. Peri-prostatic fat is reflected dorsally to either side of the gland to expose the vasculature on the dorsal surface of the gland.The prostate is rolled to the one side and the bifurcation of the A. prostatica is isolated and ligated. Care is taken to preserve the A. vesica caudalis as it courses cranially to supply the trigone area of the bladder. By rolling the prostate gland to the other side, ligation of the prostatic artery is repeated on the contralateral side.Once the prostatic blood vessels have been ligated, the diseased portion can be excised. A urinary catheter should be in place during the resection procedure, which is performed by successive passes with an electrosurgical scalpel or laser equipment. Large iatrogenic rents or pre-existing fistulas into the prostatic urethra should be closed with 4/0 PDS sutures in a single interrupted pattern. If any significant communication exists with the prostatic urethra, a Foley’s cystostomy catheter should be used to divert the urine away from the prostate lesion for 7 to 10 days, while the urethral epithelium heals.Following the resection of a portion of the prostate gland, Gelfoam? or Surgicell? should be used along with firm pressure to control haemorrhage from the remaining glandular tissue.If infection is present in the gland at the site of resection, the entire area should be well flushed with sterile Ringer's lactate solution with an appropriate antibiotic in it. Local abdominal drainage with two Penrose drains or prostatic parenchymal omentelization is advised following this procedure.Total prostatectomy (*NFEP)This is a highly invasive surgical procedure in the dog and should be preserved only for patients with "end-stage" prostatic disease. Extensive saccular abscessation and primary prostatic neoplasia (adenocarcinoma) without metastasis to the lungs or other organs are the most common indications.ReferencesChristie T R. Prostate gland and Testes, In: Current Techniques in Small Animal Surgery, Bojrab MJ (ed.) Lea & Febiger, Philadelphia, 1983: 360 - 369Johnston D E, Archibald J. Male Genital System - prostate gland (surgical procedures), In: Canine and Feline Surgery, Vol 1, Abdomen, Archibald J & Catcott E J (eds.), American Veterinary Publications, California, 1984: 335 - 355 ................
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