Ureteral Reimplantation Psoas Hitch And Boari Flap

Ureteral reimplantation is a surgical procedure performed to correct or improve the function of the ureter, the tube that carries urine from the kidney to the bladder. When the ureter is damaged, blocked, or abnormally positioned, it can lead to various complications, including urinary tract infections (UTIs), kidney damage, and urinary incontinence. Ureteral reimplantation aims to re-establish a healthy connection between the ureter and the bladder, ensuring proper urine flow. In complex cases where the ureter is significantly shortened or damaged, advanced techniques such as the psoas hitch and Boari flap are employed to achieve a successful reimplantation. This article delves into the intricacies of ureteral reimplantation, focusing on the psoas hitch and Boari flap procedures, their indications, surgical techniques, and outcomes.

Understanding Ureteral Reimplantation

Ureteral reimplantation, also known as ureteroneocystostomy, involves surgically disconnecting the ureter from its current location and reattaching it to a different site on the bladder. This procedure is often necessary when the ureter is obstructed, refluxing (urine flowing backward towards the kidney), or damaged due to trauma or surgery. The primary goal is to create a tension-free, watertight anastomosis (connection) between the ureter and the bladder, preventing complications such as urine leakage and stricture formation.

Indications for Ureteral Reimplantation

Ureteral reimplantation is indicated in various clinical scenarios, including:

Vesicoureteral Reflux (VUR): This condition involves the retrograde flow of urine from the bladder into the ureters and kidneys. It is a common cause of UTIs in children and can lead to kidney damage if left untreated.
Ureteral Obstruction: Blockages in the ureter can result from congenital abnormalities, strictures, stones, or external compression. Reimplantation can bypass the obstruction and restore normal urine flow.
Ureteral Injuries: Trauma, surgery, or radiation therapy can cause damage to the ureter, necessitating reimplantation to repair the injury.
Ureteral Fistulas: Abnormal connections between the ureter and adjacent organs (e.g., vagina, bowel) can lead to urine leakage and infection. Reimplantation can close the fistula and restore urinary tract integrity.
Ureteral Strictures: Narrowing of the ureter can occur due to inflammation, scarring, or previous surgery. Reimplantation can excise the strictured segment and create a wider, more patent anastomosis.

Traditional Ureteral Reimplantation Techniques

Several techniques are available for ureteral reimplantation, depending on the specific clinical situation. The most common approaches include:

Cohen Cross-Trigonal Reimplantation: This technique involves tunneling the ureter across the bladder trigone (the triangular area between the ureteral orifices and the bladder neck) and reattaching it to the opposite side. It is often used for VUR correction.
Politano-Leadbetter Reimplantation: This method involves mobilizing the ureter and creating a submucosal tunnel in the bladder wall before reattaching the ureter. It is suitable for various indications, including VUR and ureteral obstruction.
Lich-Gregoir Technique: This extravesical approach involves reimplanting the ureter without entering the bladder. It is primarily used for VUR correction in children.

Psoas Hitch: An Advanced Technique

In cases where the ureter is significantly shortened or cannot reach the bladder without tension, a psoas hitch procedure can be employed. The psoas hitch involves mobilizing the bladder and securing it to the psoas major muscle, a large muscle in the lower back. This maneuver effectively shortens the distance between the ureter and the bladder, allowing for a tension-free anastomosis.

Indications for Psoas Hitch

The psoas hitch is indicated in situations where standard ureteral reimplantation techniques are insufficient to achieve a tension-free anastomosis. Specific indications include:

Short Ureter: When the ureter is congenitally short or has been shortened due to injury or surgery, a psoas hitch can bridge the gap between the ureter and the bladder.
High Ureteral Injuries: Injuries to the upper ureter, close to the kidney, may require a psoas hitch to bring the bladder up to the level of the injury.
Failed Previous Reimplantation: If a previous ureteral reimplantation has failed due to tension or stricture, a psoas hitch can provide a more durable solution.
Radiation-Induced Ureteral Damage: Radiation therapy can cause fibrosis and shortening of the ureter, necessitating a psoas hitch for successful reimplantation.

Surgical Technique of Psoas Hitch

The psoas hitch procedure involves several key steps:

Patient Positioning and Incision: The patient is typically placed in a supine position with the affected side slightly elevated. A lower midline or Pfannenstiel incision is made to access the bladder and retroperitoneum.
Bladder Mobilization: The bladder is extensively mobilized from its surrounding attachments, including the peritoneum and lateral ligaments. This allows the bladder to be advanced superiorly towards the psoas muscle.
Ureteral Dissection and Preparation: The ureter is carefully dissected and mobilized, ensuring adequate length for reimplantation. Any damaged or strictured segments are excised.
Psoas Muscle Exposure: The psoas major muscle is identified and exposed. The peritoneum overlying the muscle is incised, and the muscle is cleared of any surrounding tissue.
Bladder Fixation to Psoas: The bladder is advanced towards the psoas muscle, and the bladder wall is secured to the muscle using non-absorbable sutures. Multiple sutures are placed to ensure a secure and tension-free fixation.
Ureteral Reimplantation: The ureter is reimplanted into the bladder using a standard technique, such as the Politano-Leadbetter or Cohen cross-trigonal method. A watertight anastomosis is created to prevent urine leakage.
Drainage and Closure: A drain is placed near the reimplantation site to monitor for any urine leakage. The incision is closed in layers, and a Foley catheter is inserted into the bladder to provide urinary drainage during the healing process.

Advantages and Disadvantages of Psoas Hitch

The psoas hitch offers several advantages:

Tension-Free Anastomosis: By mobilizing and securing the bladder to the psoas muscle, the procedure eliminates tension on the ureteral anastomosis, reducing the risk of stricture and leakage.
Versatility: The psoas hitch can be used in various clinical scenarios, including short ureters, high ureteral injuries, and failed previous reimplantations.
Durable Results: When performed correctly, the psoas hitch provides long-lasting results with a low rate of complications.

However, the psoas hitch also has some disadvantages:

Increased Surgical Complexity: The procedure requires extensive bladder mobilization and fixation to the psoas muscle, increasing the complexity and duration of the surgery.
Potential for Bladder Devascularization: Excessive mobilization of the bladder can compromise its blood supply, leading to ischemia and potential complications.
Risk of Psoas Muscle Injury: Although rare, there is a risk of injury to the psoas muscle during the fixation process.
Bladder Capacity Reduction: In some cases, the psoas hitch can reduce bladder capacity due to the altered bladder position.

Boari Flap: Another Advanced Technique

The Boari flap is another advanced surgical technique used in ureteral reimplantation to bridge long ureteral defects. It involves creating a flap from the bladder wall and tubularizing it to extend the bladder superiorly, effectively lengthening the ureter. The Boari flap is particularly useful when the ureteral defect is too long to be bridged by a psoas hitch alone.

Indications for Boari Flap

The Boari flap is indicated in situations where the ureteral defect is too long to be managed by standard reimplantation techniques or a psoas hitch alone. Specific indications include:

Long Ureteral Strictures: When a long segment of the ureter is affected by stricture, a Boari flap can excise the strictured segment and provide a conduit for urine flow.
Extensive Ureteral Injuries: In cases of significant ureteral trauma, such as gunshot wounds or avulsions, a Boari flap can reconstruct the damaged ureter.
Ureteral Tumors: Resection of ureteral tumors may result in a long ureteral defect, requiring a Boari flap for reconstruction.
Failed Previous Reconstruction: If previous attempts to reconstruct the ureter have failed, a Boari flap can provide a more extensive and durable solution.

Surgical Technique of Boari Flap

The Boari flap procedure involves the following steps:

Patient Positioning and Incision: The patient is placed in a supine position, and a lower midline or Pfannenstiel incision is made to access the bladder and retroperitoneum.
Bladder Mobilization: The bladder is extensively mobilized from its surrounding attachments, similar to the psoas hitch procedure.
Flap Design and Creation: A rectangular flap is designed on the anterior bladder wall, based on the superior vesical pedicle to ensure adequate blood supply. The flap is typically 4-5 cm wide and long enough to reach the level of the ureteral defect.
Tubularization of the Flap: The flap is tubularized over a catheter using absorbable sutures to create a conduit that extends from the bladder to the ureter.
Ureteral Anastomosis: The proximal end of the Boari flap is anastomosed to the distal end of the ureter using a watertight technique. The anastomosis should be tension-free to prevent stricture formation.
Bladder Closure: The remaining bladder defect is closed in layers, ensuring a watertight seal.
Drainage and Closure: A drain is placed near the anastomosis site to monitor for urine leakage. A Foley catheter is inserted into the bladder to provide urinary drainage during the healing process.

Advantages and Disadvantages of Boari Flap

The Boari flap offers several advantages:

Long Ureteral Defect Reconstruction: The Boari flap can bridge long ureteral defects that cannot be managed by other techniques.
Good Blood Supply: The flap is based on the superior vesical pedicle, ensuring a reliable blood supply to the reconstructed ureter.
Durable Results: When performed correctly, the Boari flap provides long-lasting results with a low rate of complications.

However, the Boari flap also has some disadvantages:

Increased Surgical Complexity: The procedure requires careful flap design and tubularization, increasing the complexity and duration of the surgery.
Potential for Bladder Capacity Reduction: The Boari flap can reduce bladder capacity, especially if a large flap is required.
Risk of Flap Necrosis: Although rare, there is a risk of flap necrosis if the blood supply is compromised.
Urine Leakage: Urine leakage from the anastomosis site is a potential complication, especially if the anastomosis is not watertight.

Psoas Hitch and Boari Flap: Combining Techniques

In some complex cases, the psoas hitch and Boari flap techniques may be combined to achieve a successful ureteral reimplantation. This approach is typically reserved for situations where the ureteral defect is very long, and the bladder needs to be both mobilized and augmented to reach the ureter.

Indications for Combined Psoas Hitch and Boari Flap

The combined psoas hitch and Boari flap are indicated in the following situations:

Extremely Long Ureteral Defects: When the ureteral defect is too long to be bridged by either a psoas hitch or a Boari flap alone, the combined approach can provide the necessary length and support.
Complex Ureteral Reconstruction: In cases of complex ureteral injuries or tumors, a combination of techniques may be required to achieve a successful reconstruction.
Failed Previous Reconstructions: If previous attempts to reconstruct the ureter have failed, a combined psoas hitch and Boari flap can provide a more comprehensive and durable solution.

Surgical Technique of Combined Psoas Hitch and Boari Flap

The surgical technique for the combined psoas hitch and Boari flap involves performing both procedures in sequence:

Psoas Hitch: The bladder is mobilized and secured to the psoas muscle, as described earlier.
Boari Flap: A rectangular flap is designed on the anterior bladder wall, tubularized, and anastomosed to the distal end of the ureter, as described earlier.

The psoas hitch provides additional length and support to the Boari flap, ensuring a tension-free anastomosis and reducing the risk of complications.

Outcomes and Complications

Ureteral reimplantation with psoas hitch and Boari flap are complex surgical procedures that require meticulous technique and careful patient selection. The success rates for these procedures are generally high, with most patients experiencing significant improvement in their urinary symptoms and renal function.

Outcomes:

Resolution of VUR: In patients with VUR, ureteral reimplantation can effectively eliminate reflux and prevent recurrent UTIs.
Relief of Ureteral Obstruction: Reimplantation can restore normal urine flow in patients with ureteral obstruction, preventing kidney damage.
Improved Urinary Continence: In patients with ureteral fistulas, reimplantation can close the fistula and restore urinary continence.

Complications:

Urine Leakage: Urine leakage from the anastomosis site is a potential complication, which may require prolonged drainage or reoperation.
Ureteral Stricture: Scarring at the anastomosis site can lead to ureteral stricture and obstruction.
Bladder Capacity Reduction: The psoas hitch and Boari flap can reduce bladder capacity, leading to increased urinary frequency.
Wound Infection: Wound infection is a risk with any surgical procedure.
Psoas Muscle Injury: Although rare, there is a risk of injury to the psoas muscle during the psoas hitch procedure.
Flap Necrosis: Flap necrosis is a potential complication of the Boari flap, especially if the blood supply is compromised.

Conclusion

Ureteral reimplantation is a valuable surgical technique for correcting or improving the function of the ureter. In complex cases where the ureter is significantly shortened or damaged, advanced techniques such as the psoas hitch and Boari flap can be employed to achieve a successful reimplantation. These procedures require meticulous surgical technique and careful patient selection to minimize the risk of complications and ensure optimal outcomes. By understanding the indications, surgical techniques, and potential outcomes of these procedures, surgeons can provide effective and durable solutions for patients with complex ureteral problems.