Robert S. Figenshau

Effects of rectal examination, prostatic massage, ultrasonography and needle biopsy on serum prostate specific antigen levels

Measurement of serum prostate specific antigen (PSA) is commonly used to evaluate the prostate gland in a variety of clinical settings. We examined the effects of prostatic manipulations, including digital rectal examination, prostate massage, transrectal ultrasonography and transrectal needle biopsy, on serum PSA levels in 199 men. We detected no clinically significant difference between serum PSA levels obtained immediately before and at 5 or 90 minutes after rectal examination in 43 men. We observed falsely increased PSA levels (to greater than 4 ng./ml., Tandem-R) in 1 of 17 men (6%) following prostatic massage and in 3 of 27 men (11%) following ultrasonography. Transrectal needle biopsy caused an immediate increase in serum PSA in 92 of 100 men. In 29 of these 92 men (32%) when followed weekly serum PSA levels did not return to baseline as expected according to the published serum PSA half-life of 2 to 3 days. Biopsies taking 3 or fewer cores (7 patients) resulted in a smaller increase in serum PSA (mean 1.63 +/- 1.12 times the baseline level versus 6.24 +/- 1.10 times baseline, p less than 0.03) and a proportionally shorter duration of PSA elevation (mean 1.43 +/- 0.48 weeks versus 2.13 +/- 0.14 weeks, p = 0.20) than those taking 4 or more cores (93 patients). Prostate size and the presence of cancer had no influence on the duration of PSA elevation following biopsy. We conclude that digital rectal examination, prostatic massage and ultrasonography have minimal effects on serum PSA levels in most patients. However, prostatic needle biopsy usually causes marked elevations of serum PSA levels with a persistent PSA leak into the blood stream lasting longer than expected from the serum half-life of PSA in approximately 25% of the patients.

Laparoscopic partial nephrectomy in the pig model.

In an effort to further evaluate the potential application of laparoscopy to urologic surgery, we explored the feasibility of using this minimally invasive approach for performing a partial nephrectomy. Nine female pigs underwent laparoscopic partial nephrectomy (LPN) utilizing a plastic cable tie (15 mm. x 4 mm. x 1 mm.) to achieve renal ischemia and an Argon Beam Coagulator probe (ABC) (Birtcher Medical Systems) to fulgurate the transected surface. Six weeks after LPN, 6 pigs underwent creatinine clearance, renin level, arteriography, BP samples and were then killed. The renal remnants were weighed and sectioned for histological studies. These studies revealed excellent function of the renal remnant, no AV fistula, and no evidence of renovascular hypertension. LPN is a feasible, repeatable procedure in the pig. Control of the renal hilum, transient parenchymal compression with a plastic cable, and use of the argon beam coagulator are key elements in performing this procedure.

Robot-Assisted Partial Nephrectomy: An International Experience

BACKGROUND Robot-assisted partial nephrectomy (RAPN) is emerging as a viable approach for nephron-sparing surgery (NSS), though many reports to date have been limited by evaluation of a relatively small number of patients. OBJECTIVE We present the largest multicenter RAPN experience to date, culling data from four high-volume centers, with focus upon functional and oncologic outcomes. DESIGN, SETTING, AND PARTICIPANTS A retrospective chart review was performed for 183 patients who underwent RAPN at four centers between 2006 and 2008. SURGICAL PROCEDURE RAPN was performed using methods outlined in the supplemental video material. Though operative technique was similar across all institutions, there were minor variations in trocar placement and hilar control. MEASUREMENTS Perioperative parameters, including operative time, warm ischemic time, blood loss, and perioperative complications were recorded. In addition, we reviewed functional and oncologic outcomes. RESULTS AND LIMITATIONS Mean age at treatment was 59.3 yr. Mean tumor size was 2.87 cm. Mean total operative time was 210 min while mean ischemic time was 23.9 min. Calyceal repair was required in 52.1% of procedures. Mean estimated blood loss was 131.5 ml. Sixty-nine percent of excised tumors were malignant, of which 2.7% exhibited positive surgical margins. The incidence of major complications was 8.2%. At up to 26 mo follow-up, there have been no documented recurrences and no significant change in serum creatinine (1.03 vs 1.04 mg/dl, p=0.84) or estimated glomerular filtration rate (eGFR) from baseline (82.2 vs 79.4 mg/ml per square meter, p=0.74). The study is limited by its retrospective nature, and the outcomes are likely influenced by the robust prior laparoscopic renal experience of each of the surgeons included in this study. CONCLUSIONS RAPN is a safe and efficacious approach for NSS, offering short ischemic times, as well as perioperative morbidity equivalent to other standard approaches. Moreover, RAPN is capable of providing patients with excellent functional and oncologic outcomes.

BLADDER WALL SUBSTITUTION WITH SYNTHETIC AND NON-INTESTINAL ORGANIC MATERIALS

PURPOSE We evaluate and compare the characteristics and drawbacks of different synthetic and organic materials that have been used for bladder wall replacement. MATERIALS AND METHODS We extensively reviewed the contemporary literature for partial bladder wall replacement with synthetic or organic materials. RESULTS The concept of bladder wall replacement dates back to the early nineteenth century. Based on the unique regenerative capability of the bladder, many organic and synthetic allografts and xenografts were implanted in the bladder wall with a wide range of outcomes. Recently, various biodegradable allografts have been developed and used successfully in animal models. Despite the favorable animal results, only a few of the materials have been used clinically for bladder wall replacement to date. CONCLUSIONS Further improvements in the use of existing materials and development of new materials will hopefully result in clinically successful grafts for bladder wall replacement and for whole bladder substitution.

Effect of Stent Duration on Ureteral Healing Following Endoureterotomy in an Animal Model

Ureteral strictures were created in 18 minipigs. Six weeks after stricture inducement, endourologic incision with a balloon cutting device was performed and a 7 F internal polyurethane stent was placed. After this step, 14 pigs remained in the study and were randomized into three different groups depending upon the time when the stent was removed: 1, 3 or 6 weeks. Twelve weeks after stricture incision, the pigs were killed, the status of the incised ureteral segment was evaluated histologically, and a healing score was determined. There were no statistically significant overall differences among the mean values of the overall healing score throughout the three different groups. However, when the one-week and the six-week groups (p < .05) were compared with respect to strictures requiring more than one incision due to stricture length greater than 2 centimeters, a more favorable outcome occurred in the 1 week group. Based on these findings it may be reasonable to remove ureteral stents as early as 1 week after endoureterotomy and endopyelotomy.

Positive Margin During Partial Nephrectomy: Does Cancer Remain in the Renal Remnant?

OBJECTIVE To examine the outcomes of patients with a positive surgical margin by gross and/or frozen examination during partial nephrectomy, in whom a re-resection of the margin or a completion nephrectomy was performed. METHODS Patients with renal cancer who underwent partial nephrectomy were considered. If the patient had a positive margin and underwent completion nephrectomy or re-excision of the margin, they were included. Patients with planned enucleation were excluded from the study. Clinical and pathologic information were reviewed to examine for residual cancer in the additionally resected tissue. RESULTS In the final cohort, 29 patients with a positive margin and subsequent complete parenchymal re-resection or completion nephrectomy were identified. Eight patients underwent nephrectomy, after which no residual cancer was found in the renal remnant. Twenty-one patients underwent total re-resection of the margin, of which two were found to have carcinoma. Renal functional outcomes revealed a decrease in estimated glomerular filtration rate of 25 mL/min/1.73 m(2) in patients who underwent radical nephrectomy, and 4 mL/min/1.73 m(2) in patients who underwent re-resection of the margin with preservation of the renal unit. CONCLUSIONS A positive surgical margin does not necessarily mean that cancer remains in the renal remnant in most cases. Therefore, radical nephrectomy or re-resection of the margin is overtreatment in many cases, but a small percentage of patients will harbor residual malignancy. Clinical correlation is recommended before reexcision or completion nephrectomy after a positive surgical margin, with careful consideration of the impact on subsequent renal function weighed against the possibility of residual disease.

Selective versus nonselective arterial clamping during laparoscopic partial nephrectomy: impact upon renal function in the setting of a solitary kidney in a porcine model.

INTRODUCTION Laparoscopic partial nephrectomy has emerged as a standard of care for small renal masses. Nevertheless, there remains concern over the potential for irreversible insult to the kidney as a result of exposure to warm ischemia. We aim to investigate the utility of selective segmental arterial clamping as a means to reduce the potential for ischemic damage to a solitary kidney during laparoscopic partial nephrectomy utilizing a porcine model. MATERIALS AND METHODS A total of 20 domestic swine were randomized into four equal groups. Each subject underwent laparoscopic radical nephrectomy to create the condition of a solitary kidney. On the contralateral side, a laparoscopic lower pole partial nephrectomy was performed, employing either selective or nonselective vascular clamping for either 60 or 90 minutes. Postoperatively, clinical status and serial serum studies were closely monitored for 1 week. RESULTS There were no intraoperative complications. The 90-minute nonselective clamping produced devastating effects, resulting in rapid deterioration into florid renal failure within 72 hours. The 60-minute nonselective clamping group experienced modest but significant rises in both blood urea nitrogen and creatinine. Both 60- and 90-minute selective clamping groups performed well, with no significant rises in creatinine over a 7-day period, and no instances of renal failure. CONCLUSIONS Selective arterial clamping is a safe and feasible means of vascular control during laparoscopic partial nephrectomy. In the porcine model, selective clamping appears to improve functional outcomes during prolonged periods of warm ischemic insult. Prospective evaluation of the technique in humans is necessary to determine if selective arterial control confers long-term functional benefits in patients with limited renal reserve.

Laparoscopic Retropubic Auto-Augmentation of the Bladder

The small capacity or contracted bladder is a difficult management problem. The goal of bladder augmentation is to create a storage structure with an adequate capacity and low pressure. Bladder auto-augmentation creates a large bladder diverticulum by partially excising the detrusor muscle. We report our initial experience with an extraperitoneal approach to laparoscopic auto-augmentation in a patient with a small contracted bladder. This is a technically feasible operation but longer clinical followup is necessary to determine its durability in the management of the small contracted bladder.

The Washington University Renorrhaphy for robotic partial nephrectomy: a detailed description of the technique displayed at the 2008 World Robotic Urologic Symposium

Robotic partial nephrectomy is an emerging procedure. The Washington University Renorrhaphy involves robotic assistance, rapid closure of the collecting system, and renorrhaphy with sliding nonabsorbable clips. Bolsters are rarely used. Preliminary results have shown very short ischemic times with few complications. This communication offers a short video describing the renorrhaphy.

Sliding-clip renorrhaphy provides superior closing tension during robot-assisted partial nephrectomy

OBJECTIVE Recently, our institution refined a technique for robot-assisted renorrhaphy utilizing sliding Weck Hem-O-Lock clips, which are tightened by the surgeon seated at the console and locked into place with a LapraTy clip. In addition to the relative ease of implementation, we believe that our technique also provides a superior strength of closure over other commonly used techniques. METHODS An in vivo porcine model was used to compare a sliding-clip technique against an assistant-placed LapraTy-only closure, and a surgeon-placed simple suture closure. A force gauge was used to record the maximum tension that could be applied during each closure method before the suture ripped through the renal parenchyma, thus illustrating the relative strength of each closure. RESULTS The simple suture closure performed relatively poorly, ripping through parenchyma at a mean force of 11.3 N. The LapraTy-only method allowed a maximum applicable mean force of 16.7 N. The sliding Weck clip with a LapraTy bolster provided the tightest closure, allowing for a mean force of 32.7 N before ripping through parenchyma. Statistical analysis reveals that a sliding-clip technique provides a significantly tighter closure than both of the other tested methods. CONCLUSION A sliding-clip technique allows for more tension to be safely applied to the closure of a partial nephrectomy defect than other commonly used methods. We believe that this is primarily attributable to the larger footprint of the Hem-O-Lock clip, which allows for the tension to be distributed over a greater surface area. The LapraTy then ensures the security of the closure by holding the Weck clip in place. Further studies are necessary to determine if this increased tension translates into appreciably better hemostasis.