Partial cystectomy has been used in the extirpative management of muscle-invasive bladder cancer since the mid-20th century. However, poor disease-free and disease-specific survival have largely precluded its use in this patient cohort. Improvements in surgical technique, the development of multimodal treatment strategies, and maturation in our understanding of the disease have allowed partial cystectomy to reemerge as a treatment option for muscle-invasive bladder cancer in carefully selected patients.
Although no prospective trials evaluating efficacy exist, large retrospective series demonstrating acceptable oncologic outcomes and improved sexual function encourage the use of this technique to minimize postoperative morbidity and significant quality-of-life changes associated with radical cystectomy. Unlike with nonsurgical bladder-sparing therapies, partial cystectomy is potentially superior because of accurate staging with full thickness pathologic evaluation of the tumor along with concomitant pelvic lymph node dissection. The minimally invasive approach to partial cystectomy offers the opportunity to enhance perioperative outcomes, including decreased operative blood loss, decreased postoperative pain, and shorter length of stay. Of course, careful patient selection is required to achieve equivalent oncologic efficacy; it is currently estimated that only 5% to 10% of all patients with muscle-invasive bladder cancer are eligible for partial cystectomy.
Minimally invasive bladder diverticulectomy has been the preferred method of treatment for symptomatic bladder diverticula since the diffusion of robotic surgery in urology. Multiple single and multiinstitutional series have been reported in the literature demonstrating the safety of robotic diverticulectomy and illustrating the benefits including minimal blood loss, excellent outcomes, and short recovery time. Furthermore, as robotic experience has grown, diverticulectomy can be done with robotic simple prostatectomy and ureteral reimplant.
Indications and contraindications
Critical review of patient pathology and disease history is of paramount importance when determining eligibility for partial cystectomy. In general, surgery is reserved for patients with pathologic stage T2 disease on initial staging who demonstrate invasion of the muscularis propria without imaging evidence of more locally advanced disease. Within this cohort, optimal disease features include the presence of a solitary tumor situated in the anterior bladder wall or bladder dome, away from the trigone. Resection should be performed with the intent to achieve a histologically negative margin of 2 cm; the inability to obtain an adequate disease-free perimeter would preclude partial extirpative therapy. Intraoperative frozen sections of the bladder wall taken from the edge of the resection bed should be used to ensure the absence of residual disease. Positive margins may be indicative of a more infiltrative process or multifocal disease for which radical cystectomy would be better suited.
Tumor multifocality and the concomitant presence of carcinoma in situ (CIS) are both highly predictive of disease recurrence, with the latter particularly associated with the development of advanced disease. As such, pathologic evidence of these entities during initial staging is a contraindication to partial cystectomy. Before planned partial cystectomy, the patient should undergo thorough examination of the remaining bladder, ideally with systematic mapping bladder biopsies to confirm the absence of tumor multifocality or CIS. Although partial cystectomy is typically performed on tumors in the anterior wall and bladder dome, the location is not inherently associated with oncologic outcomes. Rather, the oncologic efficacy of the operation is determined by the ability to achieve an adequate negative surgical margin. Tumors in the posterior or lateral wall are potentially amenable to an organ-sparing approach when combined with ipsilateral ureteral reimplant. However, tumors at the trigone or bladder neck are generally not amenable to a partial approach, given the technical challenge of achieving an adequate surgical margin and maintaining bladder function. Although no specific size restrictions exist, the patient should be counseled on the direct correlation between increasing size of the tumor and risk for local recurrence. Finally, patients with severe bladder dysfunction or markedly reduced bladder capacity should be counseled against partial cystectomy for bladder cancer treatment.
There are several valid indications to proceed with bladder diverticulectomy including symptomatic urinary dysfunction, recurrent urinary tract infection, recurrent bladder calculi, urinary retention, and urothelial malignancy. In general, patients should be first managed with medical therapy to address outlet obstruction and overactive bladder symptoms. Patients who are unable to tolerate the adverse effects of medical therapy or develop complications associated with incomplete bladder emptying are considered suitable candidates to proceed with diverticulectomy.
Patient preoperative evaluation and preparation
Optimal patient selection is critical before initiation of treatment. The nature and extent of disease must be accurately defined to ensure patients are not placed at increased risk for tumor recurrence or progression. Diagnosis is made most often during evaluation for either microscopic or macroscopic hematuria. Flank pain may occasionally be reported and may occur secondary to ipsilateral ureteral obstruction at the level of the bladder. Although bladder cancer does not lend itself to many positive findings on physical examination, a fixed bladder on bimanual examination or the presence of palpable lymphadenopathy may indicate an advanced disease process.
Relevant laboratory studies include urinalysis, basic metabolic profile, complete blood count, liver function tests, urine culture, and urine cytology. The presence of atypical or malignant cells on urine cytology may be suggestive of high-grade disease and warrants a thorough evaluation, particularly to rule out CIS. Cross-sectional imaging of the abdomen and pelvis is indicated during the initial workup. Computed tomography (CT) with contrast is the study of choice to help determine a potential genitourinary source. Intraluminal areas in the upper urinary tract or bladder devoid of contrast (i.e., filling defects) on delayed excretory phase images should raise suspicion for a neoplastic process. Alternatively, a more infiltrative process in the bladder may appear as asymmetric thickening of the bladder wall. If a patient cannot undergo contrast-enhanced cross-sectional imaging, retrograde pyelography and ureteroscopy can be performed at the time of cystoscopy to evaluate for upper-tract disease. More recently, dynamic contrast and diffusion-weighted magnetic resonance imaging is being used to develop more accurate clinical staging models for bladder cancer.
Cystoscopy is central to the workup because it allows direct visualization of the tumor as well as mapping of the bladder. Tumors most amenable to partial cystectomy are solitary and situated in the anterior wall or dome. Transurethral resection of the tumor should be performed with the intent to resect to completion. The concomitant presence of CIS must be ruled out. Random bladder biopsies may be performed at the time of primary tumor resection or during second-look cystoscopy. Prostatic urethral involvement would also preclude partial cystectomy. Prostatic urethral biopsy should be performed if urethral abnormalities are observed. Staging workup for muscle-invasive disease is completed with cross-sectional imaging of the chest, abdomen, and pelvis to evaluate for systemic disease. Imaging of the bone and brain is reserved for symptomatic presentation or abnormal laboratory values.
Patients should be counseled before surgery about the possible need to convert to radical cystectomy at the time of surgery (if more extensive disease or positive frozen section is discovered), and appropriate bowel preparation should be prescribed to the patient.
As with partial cystectomy, optimal patient selection is the key to a successful outcome following bladder diverticulectomy. Workup includes a thorough voiding history and physical exam with assessment of postvoid residual. Most often the diagnosis of bladder diverticulum is made on cross-sectional imaging or during cystoscopy in the evaluation of urinary symptoms. During office cystoscopy, the location of the diverticulum, proximity to the ipsilateral ureteral orifice, and the presence of mucosal abnormality within the diverticulum should be noted. Prior to proceeding with diverticulectomy in males, the urologist should either confirm that the patient is adequately treated for outlet obstruction or plan for a concomitant procedure to address the bladder outlet and prostate (e.g., transurethral resection of the prostate or simple prostatectomy).
Operating room configuration and patient positioning
For both robotic partial cystectomy and bladder diverticulectomy, all anesthetic preparations are made with the patient supine, after which the patient is placed in a dorsal lithotomy position with the hips abducted ( Fig. 36.1 ). It is critical that the patient be secured to the operating table and appropriately padded in anticipation of placement into steep Trendelenburg position. Such positioning permits the small bowel to fall out of the pelvis and enhances visualization during the transperitoneal approach. The arms are padded and tucked at the patient’s side. The thorax is taped in a crisscross manner over the shoulders and across the chest just above the costal margin; care should be taken to not restrict respiratory excursion. The groin and perineum are prepared in a sterile manner along with the abdomen and pelvis. An 18-French Foley catheter is placed.
The da Vinci system robotic tower (Intuitive Surgical, Sunnyvale, CA) can be placed at the patient’s side or between the legs (depending on which system is being used), after which the patient is placed in low lithotomy to enable steep Trendelenburg positioning. The robotic arms are subsequently docked to the trocars ( Fig. 36.2 ).