Operative approach and care pathway

A rectoprostatic fistula after prostate brachytherapy presents a formidable reconstructive challenge: radiation compromises perfusion, thickens tissues with fibrosis, and blurs planes that surgeons rely on for safe dissection. Robotic assistance can be useful in this setting by providing magnified visualization and wristed instruments for delicate, multilayer suturing. Yet technology is only part of the solution; outcomes depend on careful selection, rigorous staging of diversion, and disciplined closure techniques with vascularized tissue interposition when feasible.

The management logic follows a sequence: confirm diagnosis and map the tract; drain sepsis and divert streams; time surgery after radiation reaction stabilizes; execute tension-free, multilayer closure; and verify healing before reversing diversion. Throughout, the team should focus on functional outcomes, not just radiographic closure. That means preparing patients for a staged recovery and counseling about continence, erections, and bowel function while maintaining vigilance for recurrence.

Patient selection and timing after radiation

Recognize the clinical pattern. Patients typically present with pneumaturia, fecaluria, passage of urine per rectum, recurrent urinary tract infections, perineal pain, and sometimes peritonitis if contamination is brisk. In those previously treated with prostate radiation (brachytherapy or external beam), a fistula should be high on the differential when symptoms blend across urologic and colorectal domains.

Confirm and stage the lesion. Combine endoscopic visualization and contrast imaging to localize and characterize the communication. Flexible sigmoidoscopy can inspect rectal mucosa for ulceration or radiation proctitis. Cystoscopy assesses urethral integrity, prostate urethra involvement, and the bladder neck. A retrograde urethrogram and voiding cystourethrogram (VCUG) help delineate the tract, while cross-sectional pelvic MRI can define fibrosis, abscess cavities, and relation to the prostate apex, sphincter complex, and rectal wall.

Rule out recurrent malignancy. Before reconstruction, ensure the fistula is not driven by active cancer. Review PSA kinetics and imaging; biopsy only if indicated by concerning features. Repairing through tumor risks failure and compromises oncologic control.

Assess tissue quality and comorbidity. Evaluate rectal mucosal health, urethral scarring, and the extent of radiation change. Identify factors that can derail healing, including poorly controlled diabetes, malnutrition, steroid dependence, active smoking, or immunosuppression. Prehabilitation, nutritional optimization, and smoking cessation are tangible levers that improve tissue resilience.

Manage infection and contamination first. If patients present septic or with ongoing contamination, prioritize drainage and diversion. Treat urinary infections based on cultures and consider suppressive antibiotics if urinary or fecal contamination is unavoidable preoperatively.

Time reconstruction after radiation effects stabilize. Definitive closure is best attempted when acute radiation reaction and local inflammation have settled and when endoscopy shows healthier mucosa. In practice, a healing window is often chosen after sepsis has cleared, the tract anatomy is stable, and the patient has been optimized. Work up anemia and poor nutrition, and confirm there is no active rectal ulceration in the intended suture line.

Approach selection: transabdominal robotic versus perineal/transsphincteric. In irradiated fields, an anterior transabdominal robotic approach can offer superior visualization for multilayer closure and facilitates omental or peritoneal flap interposition. Alternative perineal or transsphincteric approaches may suit small, low tracts in non-irradiated settings but can be limited by exposure in scarred pelvises and by difficulty mobilizing healthy, vascular tissue for interposition.

• Choose robotic transabdominal repair when: the fistula is at or above the apex, the pelvis is accessible, prior surgeries have not obliterated anterior planes, and interposition tissue (omentum/peritoneum) is available.
• Consider hybrid or alternative approaches when: prior pelvic surgery or exenteration altered anatomy, ostomies limit port placement, or fistulas are very distal and small with favorable tissue quality.

Set expectations. Patients should understand that diversion may precede and outlast reconstruction, and that catheterization and staged stoma reversal are typical. Continence, sexual function, and bowel habits may change. A shared plan with urology and colorectal surgery is essential.

Perioperative diversion and intraoperative technique

Stage diversion to control streams and contamination. Many teams begin with urinary diversion using a suprapubic catheter to decompress the bladder and protect the urethral suture line later. Fecal diversion via loop colostomy or ileostomy reduces rectal contamination and allows rectal mucosa to recover if radiation proctitis is present. These steps can be performed ahead of reconstruction to reduce infection risk and improve tissue conditions.

Preoperative preparation. Treat urinary infections to sterile urine where feasible. If not already diverted, coordinate with colorectal surgery for a protective stoma. Bowel preparation and perioperative antibiotics should reflect the colorectal component of the procedure. Review imaging with the team to plan dissection planes and anticipate adhesions or narrowed pelvic access from fibrosis.

Positioning and access. Place the patient in low lithotomy and steep Trendelenburg to facilitate small bowel migration cranially. Standard robotic port placement for pelvic surgery can be used, adjusting for prior incisions or ostomy sites. A transabdominal approach allows entry into the rectovesical (or rectoprostatic) space, which is often thickened by radiation changes. Proceed meticulously to avoid rectal injury outside the fistula.

Expose the fistula and mobilize healthy tissue. Carefully dissect along natural planes anterior to the rectum and posterior to the prostate or urethra. When scarred, proceed with sharp dissection. Identify the fistulous tract and circumferentially mobilize rectal and urethral sides to healthy, bleeding tissue. Excessive traction risks tearing fragile mucosa; aim for gentle handling and wide exposure. Control small bleeding points promptly to maintain a clear field, which aids suture placement accuracy.

Debride nonviable tissue without over-resecting. Radiation can leave tissue apparently thick but poorly perfused. Freshen the fistula edges judiciously to reach viable, perfused margins while preserving length for a tension-free closure. Excessive resection can shorten the urethra or rectum and create avoidable tension.

Multilayer, tension-free closure is the core of success. A reproducible sequence is helpful:

• Rectal wall repair: Close the rectal mucosa first in a running or interrupted fashion with absorbable suture, then reinforce with a separate seromuscular layer. Keep bites generous enough to distribute tension, avoiding suture cut-through in irradiated tissue. The goal is a watertight, tension-free seal.
• Urethral repair: Close the urethral or prostatic urethra defect with fine absorbable suture. If the defect is broad, consider partial mobilization to achieve approximation without tension. Maintain a well-lubricated urethral catheter to stent the repair and prevent inadvertent needle injury.
• Interposition with vascularized tissue: Interpose healthy, well-vascularized tissue between closures to create a barrier and promote healing. Options include omentum (if reachable), a peritoneal flap fashioned from pelvic peritoneum, or other available vascularized tissue. Anchor the flap without tension, ensuring it sits snugly between rectal and urethral closures.

Why interposition matters in irradiated fields. Radiation diminishes microvascular supply and increases the risk of breakdown. A vascularized flap brings perfusion and separates suture lines, reducing cross-contamination if one layer develops a microleak. When omentum is limited by prior surgery, a peritoneal flap can be an efficient alternative in a robotic transabdominal approach.

Perform leak tests before leaving the field. After rectal repair and interposition, instill air or dilute dye into the rectum under saline to check for bubbles, and gently fill the bladder to check the urethral repair. Correct small leaks now rather than accepting a borderline closure. Drains can be placed selectively to detect collections, keeping in mind that suction near a tenuous suture line can be counterproductive.

Catheters and stents. Leave a urethral catheter across the repair to ensure continuous drainage and prevent urethral distension. Maintain the suprapubic catheter if placed, which gives flexibility for staged voiding trials and protects the urethral closure should transient retention occur during recovery.

Operative pearls and pitfalls.

• Pearl: Use the robotic third arm for steady traction to stabilize the rectal edge during mucosal suturing; minimize energy near suture lines to protect perfusion.
• Pearl: Pre-shape the interposition flap to reduce manipulation time within the pelvis; short ischemia time preserves flap viability.
• Pitfall: Incomplete mobilization leads to dog-eared closures and focal tension; plan for wide release before suturing.
• Pitfall: Missing satellite tracts; track suspicious induration circumferentially and confirm the primary closure sits on clearly viable margins.
• Decision point: If rectal mucosa looks inflamed or friable, abort definitive closure and extend fecal diversion until mucosa normalizes on follow-up endoscopy.
• Decision point: If interposition is not feasible due to prior surgery, consider alternate approaches or staged reconstruction rather than accepting a two-layer closure without a flap in a heavily irradiated field.

Postoperative care, functional outcomes, and follow-up

Immediate postoperative priorities. Maintain adequate analgesia while protecting bowel motility with an opioid-sparing regimen. Resume diet per enhanced recovery protocols when safe. Monitor drains if used; any feculent or urine output mandates prompt evaluation. Maintain urinary drainage through a urethral catheter, with the suprapubic catheter capped or used as needed to ensure low-pressure storage.

Infection surveillance and antibiotics. Continue culture-directed antibiotics perioperatively if preoperative contamination was significant. Fever, leukocytosis, or pelvic pain should trigger early imaging to exclude a collection or repair dehiscence. Drain management, if present, should be standardized with objective removal criteria.

Imaging before catheter or stoma changes. Prior to removing the urethral catheter, obtain a cystogram or VCUG to confirm no extravasation. Before reversing fecal diversion, consider a contrast enema and endoscopic inspection to verify rectal healing and mucosal health. If there is any suspicion of residual tract or inflammation, maintain diversion and re-evaluate rather than risking recurrence.

Plan staged returns to function. Structure recovery milestones: first confirm urinary healing, then carefully reintroduce voiding while the suprapubic catheter provides a safety valve. Only after rectal integrity is proven and symptoms are absent should stoma reversal be scheduled. This sequence minimizes the risk of overwhelming a fresh closure with pressure or contamination.

Continence and pelvic floor. Urinary continence may be affected by urethral scarring and prior radiation. Early referral to pelvic floor therapy can improve control. Counsel about realistic trajectories; continence may improve gradually as irritative symptoms settle and pelvic floor strength returns. Consider anticholinergic or beta-3 agonist therapy if urgency predominates, balancing side effects.

Erectile function counseling. Pelvic dissection and radiation can compromise erectile function. Set expectations and discuss options such as phosphodiesterase inhibitors, vacuum erection devices, or injection therapy, introduced when healing is secure. Address psychosexual health and provide clear timelines for safe trials.

Nutrition and lifestyle for healing. Encourage protein sufficiency, control of blood glucose, and cessation of tobacco products to promote microvascular recovery. If weight loss or malnutrition preceded surgery, continue supplementation and dietitian support until weight stabilizes and laboratory markers improve.

Recognize and manage failure early. Warning signs include return of pneumaturia or fecaluria, malodorous urine, pelvic pain, or perineal drainage. Low-threshold imaging and endoscopy can confirm early breakdown while intervention options remain less morbid. Minor radiographic leaks may be observed with prolonged catheterization if the patient is clinically well and contamination is controlled; recurrent fistula or sepsis requires re-evaluation for reintervention.

Measuring success beyond closure. Include patient-reported outcomes in follow-up: urinary symptom scores, incontinence pad counts, sexual function queries, and bowel habit assessments. A successful repair is a dry, pain-free patient with stable voiding and normalized bowel function, not merely a closed tract on imaging. Align clinic schedules with these aims, front-loading visits early to catch preventable setbacks.

Checklist for practice implementation.

• Confirm anatomy: Cystoscopy, sigmoidoscopy, targeted imaging to map the tract and surrounding fibrosis.
• Optimize first: Treat infection, divert streams, correct nutrition, stop smoking, tune comorbidities.
• Time wisely: Operate once radiation reaction stabilizes and mucosa looks viable; ensure no active cancer.
• Choose the approach: Robotic transabdominal for exposure and interposition options in irradiated fields.
• Close in layers: Rectum then urethra, with a vascularized flap between; insist on tension-free, watertight sutures.
• Test and protect: Perform leak tests; maintain urethral and suprapubic catheters; use drains selectively.
• Verify before reversal: Imaging and endoscopy confirm healing before catheter removal and stoma reversal.
• Track function: Continence, sexual function, and bowel metrics guide recovery plans.

Team and systems considerations. Coordination between urology and colorectal surgery is not optional; it is central to safe dissection, effective interposition, and reliable closure. Nursing and stoma therapy teams prepare patients and reduce post-discharge complications. Radiology support for timely cystograms and contrast enemas keeps the pathway on track. Building a standardized order set and follow-up schedule reduces variability and helps new team members align with best practices.

When to refer or escalate. Refractory radiation proctitis, suspected urethral stricture beyond the repair site, and prior complex pelvic surgery merit early referral to high-volume centers with reconstructive expertise. If interposition options are limited or the pelvis is hostile, planned staged strategies or alternative routes can avert attempts that are unlikely to succeed.

Patient counseling essentials. Provide a visual roadmap of the stages: initial diversion and infection control, definitive robotic multilayer repair with interposition, catheter-protected healing, imaging-confirmed integrity, and finally stoma reversal. Clarify that the timeline flexes to prioritize healing quality over speed. Encourage questions and document functional baselines to personalize expectations and measure progress.

Bottom line. In the irradiated pelvis, success hinges on fundamentals: meticulous patient selection and optimization, staged diversion to control contamination, multilayer, tension-free closure, vascularized interposition to overcome radiation-impaired perfusion, and imaging-confirmed healing before any reversal. Robotic assistance facilitates exposure and suturing but does not replace discipline in sequencing and technique. A measured, team-based pathway offers the best chance for durable closure and meaningful functional recovery.