Open Surgical Drainage of Retrovesical Abscess Formation

Retrovesical abscesses – collections of pus behind the bladder – are relatively uncommon but pose significant diagnostic and therapeutic challenges due to their often insidious presentation and potential for severe complications if left untreated. These abscesses typically arise from a variety of sources, ranging from extension of infections originating in the rectum or sigmoid colon, through pelvic inflammatory disease (PID) in women, or even as a consequence of urinary tract instrumentation. Early recognition is paramount; however, symptoms can be vague and mimic other more common conditions, leading to delays in diagnosis. A high index of suspicion should be maintained in patients presenting with lower abdominal pain, fever, dysuria, or obstructive voiding symptoms, particularly those with risk factors such as a history of pelvic surgery, diverticulitis, or immunocompromise. The consequences of delayed treatment can escalate quickly from localized infection to sepsis and even life-threatening conditions like septic shock.

Surgical drainage remains a cornerstone in the management of retrovesical abscesses, especially when conservative approaches fail or the abscess is large and complex. While percutaneous drainage techniques have evolved, open surgical drainage often provides more definitive access for complete evacuation of pus, debridement of necrotic tissue, and identification of the underlying source of infection. This approach allows surgeons to directly visualize the pelvic anatomy, address any fistulous tracts, and implement strategies to prevent recurrence. The decision between percutaneous versus open drainage is complex and depends on factors like abscess size, location, patient’s overall health, and surgeon experience. This article will delve into the details of open surgical drainage for retrovesical abscesses, covering indications, surgical technique, postoperative care, and potential complications.

Indications and Preoperative Evaluation

Open surgical drainage isn’t a first-line treatment in all cases of retrovesical abscess. Typically, it’s reserved for situations where percutaneous drainage is either unsuccessful, technically challenging, or contraindicated. Several factors guide the decision to proceed with open surgery:
* Failure of percutaneous drainage after adequate attempts (typically two or more). This could be due to loculated abscesses, thick pus that doesn’t drain readily, or unfavorable anatomy preventing catheter placement.
* Large abscess size (>5 cm) often necessitates a wider surgical approach for thorough evacuation and debridement.
* Presence of complex abscesses with multiple loculations or associated fistulas requires direct visualization during surgery to ensure complete resolution.
* Concern for underlying pathology such as diverticular perforation, Crohn’s disease, or bladder cancer may prompt open exploration alongside drainage.

Preoperative evaluation is crucial. A thorough history focusing on prior pelvic surgeries, inflammatory bowel disease, urinary tract infections, and sexual activity (in women) should be obtained. Physical examination should assess abdominal tenderness, rectal findings, and any evidence of peritonitis. Imaging studies are indispensable for diagnosis and surgical planning. Computed tomography (CT) scan with intravenous contrast is the imaging modality of choice, providing detailed anatomical information about the abscess location, size, and relationship to surrounding structures. Magnetic resonance imaging (MRI) might be considered in specific cases where CT findings are inconclusive or when further characterization of soft tissue involvement is needed. Laboratory investigations should include a complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and urine analysis. Broad-spectrum antibiotics are initiated preoperatively, guided by local antimicrobial resistance patterns, and adjusted based on culture results obtained from the abscess drainage.

Surgical Technique: A Step-by-Step Approach

The open surgical approach to retrovesical abscess drainage typically involves a midline laparotomy or a Pfannenstiel incision, depending on the surgeon’s preference and patient factors. Midline incisions offer excellent exposure but may be associated with increased postoperative pain; Pfannenstiel incisions are cosmetically more appealing but can limit access in obese patients or those with extensive adhesions. Once abdominal entry is achieved, careful exploration is undertaken to identify the abscess cavity and its relationship to the bladder, rectum, sigmoid colon, and pelvic vessels.

The key steps of open surgical drainage include:
1. Dissection: The peritoneum overlying the abscess is carefully dissected using blunt and sharp techniques. Adhesions should be meticulously lysed to avoid injury to surrounding structures.
2. Abscess Identification & Incision: Once the abscess cavity is identified, an incision is made through the peritoneum into the abscess. Gentle palpation can help delineate the extent of the abscess and identify any loculations.
3. Drainage and Debridement: The abscess is thoroughly drained, and all necrotic tissue or debris is meticulously debrided. Culture specimens are sent for microbiological analysis to guide antibiotic therapy.
4. Source Control: Identifying and addressing the source of infection is crucial. This might involve diverting loops of bowel if a perforation exists, resecting diseased segments of the colon in cases of diverticulitis, or exploring the bladder for potential underlying pathology.
5. Irrigation & Drainage Placement: The abscess cavity is copiously irrigated with saline solution. A drain – typically a Jackson-Pratt or Penrose drain – is placed to facilitate continued drainage and prevent reaccumulation of pus. The choice of drain depends on the volume of fluid expected and surgeon preference.
6. Closure: The peritoneum is closed loosely, leaving space for drainage, and the abdominal wall is closed in layers using standard surgical techniques.

Postoperative Management

Postoperative care focuses on preventing complications and ensuring complete resolution of the infection. Patients are monitored closely for signs of sepsis, wound infection, or urinary tract symptoms. Antibiotics are continued postoperatively based on culture results and clinical response. The drainage tube is typically removed once drainage decreases significantly – usually within 5-7 days – but this depends on the individual patient’s progress. Pain management is essential to facilitate early mobilization and prevent postoperative ileus. Bowel function should be restored as quickly as possible, often with a combination of clear liquids progressing to a regular diet. Patients are encouraged to ambulate early to reduce the risk of deep vein thrombosis (DVT).

Potential Complications

While open surgical drainage is effective, it’s not without potential complications. Common complications include:
* Wound infection: This can be minimized with meticulous surgical technique and appropriate postoperative wound care.
* Bladder injury: Careful dissection near the bladder is essential to avoid inadvertent damage.
* Rectal or sigmoid colon injury: Similarly, cautious approach during dissection around these structures minimizes risk.
* Sepsis: Although drainage aims to prevent sepsis, it can still occur if underlying infection isn’t adequately addressed or complications arise postoperatively.
* Ileus: Prolonged postoperative ileus can lead to abdominal distention and discomfort; early mobilization and bowel-stimulating medications can help mitigate this risk.
* Fistula formation: In cases of complex abscesses, fistula formation between the bladder, rectum, or vagina is a potential complication requiring further intervention.

Long-Term Follow-Up

Long-term follow-up is crucial to assess for recurrence and address any residual symptoms. Patients should be monitored for signs of chronic pelvic pain, urinary frequency, or bowel dysfunction. Repeat imaging studies – typically CT scan – may be indicated if symptoms recur or concerns arise about abscess reformation. Addressing the underlying cause of the abscess is essential to prevent future episodes. This might involve managing inflammatory bowel disease, treating chronic constipation, or addressing any anatomical abnormalities predisposing to infection. Patient education regarding hygiene, dietary modifications, and warning signs of infection is also vital for long-term management.