David A. Duchene

Histopathology of surgically managed renal tumors: analysis of a contemporary series

OBJECTIVES To review the pathologic findings of a contemporary series of surgically treated renal tumors suspicious for malignancy to assess the frequency of benign disease in the modern era. The extensive application of modern imaging techniques has led to an increase in the number of incidentally discovered solid renal masses, many of which are small. A significant proportion of small renal tumors are benign or are low-grade malignancies. METHODS The records of all patients at our institution who underwent treatment for a renal mass suspicious for malignancy between November 1999 and July 2002 were retrospectively reviewed. RESULTS A total of 173 patients with 186 renal tumors had pathologic information available for analysis. Of the 186 tumors, 48% were discovered incidentally. For masses 4 cm or less, the percentage of incidentally discovered tumors increased to 58%. The pathologic evaluation demonstrated malignancy in 160 (86%) and benignity in 26 (14%) overall. For tumors 4 cm or less, 18 (20%) of 90 were benign; for tumors between 4 and 7 cm, 8 (17%) of 47 benign. No tumors greater than 7 cm were benign. All renal cell carcinomas less than 2 cm in size were Fuhrman grade 1 or 2. CONCLUSIONS Small renal tumors, many of which are incidentally discovered, are often benign or are low-grade malignancies. For tumors 4 cm or less, the frequency of benign pathologic findings is greater than previously quoted in published reports. As a result, we recommend parenchymal-sparing approaches whenever possible.

Nephrectomy after radiofrequency ablation-induced ureteropelvic junction obstruction: potential complication and long-term assessment of ablation adequacy

Little information is available concerning the morbidity of radiofrequency ablation (RFA) or the evolution of an RFA lesion over time. We report our findings in a kidney removed 1 year after RFA of a 2.3-cm renal tumor. After RFA, the patient experienced flank pain, followed by hydronephrosis, ureteropelvic junction obstruction, and eventual loss of function in the treated kidney. Nephrectomy revealed no residual renal cell carcinoma. RFA can completely destroy renal cell carcinoma in situ without histologic evidence of persistence or recurrence for up to 1 year after treatment. Care must be taken to avoid concurrent damage to the collecting system.

Safety and Peri-Operative Outcomes During Learning Curve of Robot-Assisted Laparoscopic Prostatectomy: A Multi-Institutional Study of Fellowship-Trained Robotic Surgeons Versus Experienced Open Radical Prostatectomy Surgeons Incorporating Robot-Assisted Laparoscopic Prostatectomy

PURPOSE To analyze and compare the safety and peri-operative outcomes of fellowship-trained robotic surgeons (FEL) and experienced open surgeons (OE) incorporating robot-assisted laparoscopic prostatectomy (RALP) into practice. MATERIALS AND METHODS Multiinstitutional, prospective data were collected on the first 30 RALP performed by FEL and OE (defined as over 1000 prostatectomies) incorporating RALP into practice. Morbidity from the peri-operative course was evaluated as were operative outcomes. The second 30 cases from the OE group were evaluated to assess for improvement with experience. RESULTS There were no rectal injuries or death in either group. Blood transfusion rates did not differ between the two groups (2% vs. 3%, p = 0.65). Open conversion occurred three times in the OE group but only within the first 30 cases. In the first 30 cases FEL had statistically lower rates of positive margins (15% vs. 34%, p = 0.008) and decreased likelihood of prolonged urethral catheter leakage (5% vs. 19%, p = 0.009). The FEL group had lower rates of failure of prostate-specific antigen to nadir < 0.15 ng/mL (2% vs. 10%, p = 0.056). There were no reoperations in the FEL group but present in 2% of the OE group initially. The second 30 cases of the OE group noted a statistical improvement for all parameters with margin rates and the requirement of prolonged catheterization becoming statistically comparable to those of the FEL group. CONCLUSIONS OE can safely incorporate RALP into practice and achieve outcomes comparable to FEL quickly. As anticipated, FEL achieve these endpoints earlier in their practice.

Ureteral replacement using small-intestinal submucosa and a collagen inhibitor in a porcine model.

PURPOSE Small-intestinal submucosa (SIS) has been successful as an onlay graft in ureteral repair, but tubularized segment interposition of SIS has been unsuccessful. Our objective was to evaluate whether a type I collagen inhibitor, halofuginone, would prevent stricture formation in tubularized SIS interposition. MATERIALS AND METHODS We performed either laparoscopic partial ureteral excision followed by an SIS onlay graft (N = 5) or complete laparoscopic ureteral excision followed by an SIS interposition graft (N = 7) in domestic pigs. Animals received either no (N = 3), low-dose (N = 5), or high-dose (N = 4) halofuginone. Animals had ureteral stenting for 2 weeks after surgery and were permitted to survive for 6 or 9 weeks. An intravenous urogram (IVU) was performed prior to sacrifice. Kidneys were examined grossly and histologically. RESULTS One animal that received an onlay graft died of an unrelated illness. The remaining four ureteral onlay animals, including one control and two low-dose and one high-dose pig, had grossly normal kidneys at harvest. The IVU was normal in the control and high-dose animal but showed delayed excretion with mild hydroureteronephrosis in the low-dose animals. Pathologic examination of the SIS site revealed circumferential reepithelialization with inflammation and mild fibrosis. All seven tubularized interposition graft kidneys demonstrated either severe hydroureteronephrosis (N = 5) or renal atrophy (N = 2), and all had complete obstruction on IVU. Pathologic examination revealed a stenotic ureteral lumen with extensive surrounding inflammation and fibrosis. CONCLUSIONS An SIS onlay graft was successful in the porcine model of ureteral injury. Halofuginone, a type I collagen inhibitor, did not demonstrate a significant beneficial effect in this technique. Ureteral tubularized interpositions with SIS are unsuccessful and not improved by halofuginone.

Changing Management of Organ-Confined Renal Masses

BACKGROUND AND PURPOSE Rapid evolution of laparoscopic and ablative techniques is changing the approach to renal masses. We evaluated our approach to managing renal masses in light of newly available technology. PATIENTS AND METHODS The records for all patients who underwent treatment for a renal mass between January 2000 and July 2002 at UT Southwestern Medical Center were reviewed for patient demographics, operative details, and pathology results. There were 180 patients with 190 masses. Of the 190 masses, 97 were <4 cm, 47 were between 4 and 7 cm, and 46 were >7 cm. RESULTS Most tumors >7 cm were managed with open radical nephrectomy (RN). For patients with masses between 4 and 7 cm, the majority were treated with laparoscopic RN, while 21% were treated by open partial nephrectomy (PN). Tumors <4 cm were treated with the widest variety of approaches. Open PN was the most commonly utilized, followed by laparoscopic RN and percutaneous ablation. The number of laparoscopic and percutaneous ablative procedures increased significantly with time, from none in the first year to 13% (7/55) and 29% (16/55) in the last year, respectively. Benign pathology was found in 20%, 17%, and none of lesions <4, 4 to 7, and >7 cm, respectively. CONCLUSIONS The addition of laparoscopy and ablative technologies has increased the treatment options for patients with renal masses. We propose a treatment algorithm that incorporates ablative technologies and favors parenchyma-sparing approaches for small lesions.

Laparoscopic Donor Nephrectomy

Since it first was performed in 1995, laparoscopic donor nephrectomy (LDN) has grown to be the standard of care in most transplant centers in the United States. This article reviews the current indications, selection criteria, surgical approaches, outcomes, and complications of LDN.

Systemic and cell-specific immune response to laparoscopic and open nephrectomy in porcine model.

PURPOSE To determine differences in the systemic and cell-specific immune response to open and laparoscopic nephrectomy in the porcine model. MATERIALS AND METHODS Twenty male pigs (25-40 kg) were vaccinated with human adenovirus containing ovalbumin (Ova) and 3 weeks later underwent a sham procedure (N = 4), laparoscopic nephrectomy (LN)(N = 8), or open nephrectomy (ON) (N = 8). Blood was collected after anesthesia induction and immediately and 24 and 48 hours postoperatively and assayed for complete blood count (CBC), cortisol, and C-reactive protein (CRP). Natural killer (NK) cells were isolated and stimulated in vitro for 48 hours with polyinosinic:polycytidylic acid (Poly I:C) and interleukin (IL)-2 to determine cytotoxic activity. Peripheral blood mononuclear cells (PBMC) were isolated for flow cytometry staining with CD8, CD4, and CD25 markers. Additional PBMCs were stimulated in vitro with Ova and ConA for 48 hours to measure the production of IL-10 and interferon (IFN)-gamma and a thymidine-incorporation assay to determine T-cell proliferation. RESULTS One animal in the ON group had signs of infection preoperatively and was removed from analysis. The LN took significantly longer than ON or sham nephrectomy (P = 0.002). Blood loss and animal weight were similar in the three groups. The CRP concentration increased more in the ON than the LN and sham-treatment groups in the first 48 hours (P = 0.01). No statistical differences were seen in the elevation of white blood cells or cortisol concentration. All groups demonstrated a decrease in the cytotoxic activity of NK cells postoperatively, with a significantly greater decrease in the sham-treated animals (P = 0.004). The LN group demonstrated greater T-cell activation than the ON and sham-treatment groups with both CD4(+) (P = 0.002) and CD8(+) (P = 0.028) cells increasing their expression of the activation marker CD25. The thymidine-incorporation assay demonstrated decreased T-cell proliferation in the ON group when stimulated with ConA (P = 0.014). Production of IL-10 decreased in the sham-treated and LN animals while increasing after ON. There was no difference in IFN-gamma among the groups. CONCLUSIONS In a porcine model, ON produces higher CRP concentrations postoperatively, a larger decrease in T-cell proliferation ability, and more IL-10 activity than LN or sham treatment. Animals undergoing LN demonstrated greater T-cell activation postoperatively. White blood cell counts, serum cortisol concentration, and production of IFN-gamma were similar among the groups. These findings suggest ON causes greater immune suppression than LN in the porcine model.

Current minimally invasive practice patterns among postgraduate urologists.

PURPOSE To determine laparoscopic and robotic surgical practice patterns among current postgraduate urologists. MATERIALS AND METHODS There were 9,095 electronic surveys sent to practicing urologists with e-mail addresses registered with the American Urological Association. RESULTS Responses were received from 864 (9.5%) urologists; 84% report that laparoscopic or robotic procedures are performed in their practice. The highest training obtained by the primary laparoscopist was fellowship (31%), residency (23%), or 2- to 3-day courses (22%). Eighty-six percent report performance of laparoscopic nephrectomy in their practice, and 71% consider it the standard of care. Sixty-six percent of practices have access to at least one robotic unit, and 9% plan on purchasing one within a year. Attitudes toward robotics are favorable, with 80% indicating that it will increase in volume and potential procedures. Thirty-one percent state that robot-assisted prostatectomy is standard of care, while 50% believe this procedure looks promising. Respondents think that optimal training in minimally invasive techniques is fellowships (23%), minifellowships (23%), or hands-on courses (23%). Twenty-nine percent think that they were trained adequately in laparoscopy and robotics from residency, and 62% believe residents should be able to perform most laparoscopic procedures on completion of residency. CONCLUSIONS The practice and availability of laparoscopic and robotic procedures have increased since previous evaluations. Opinions regarding these techniques are favorable and optimistic. As the field of urology continues to see a growing demand for minimally invasive procedures, training of postgraduate urologists and residents remains essential.

Robotic Reconstruction of Lower Ureteral Strictures

Distal ureteral reconstruction is increasingly being performed by minimally-invasive surgical techniques. The robotic surgical platform provides an additional modality for repairing distal ureteral defects with the associated benefits of a minimally-invasive approach. This article reviews and describes the technical aspects of robotic distal ureteral reconstruction. In addition to discussion of the operative technique, factors such as patient selection, preoperative and postoperative evaluation, and published outcomes are addressed.

Robotic-assisted Laparoscopic Pyeloplasty: Analysis of Symptomatic Patients With Equivocal Renal Scans

OBJECTIVES To review the objective and subjective success rates of robotic-assisted laparoscopic pyeloplasty in symptomatic patients with radiographic findings suggestive of uretero-pelvic junction obstruction (UPJO), but equivocal renal scans (diuretic T1/2 <20 minutes). METHODS We reviewed 77 patients with symptomatic UPJO, who underwent robotic-assisted laparoscopic pyeloplasty between August 2006 and March 2013. We grouped patients by renal scan findings into 1 of 2 groups, obstructed (diuretic T1/2 ≥20 minutes) or equivocal (diuretic T1/2 <20 minutes). All patients were symptomatic and had radiographic findings suggestive of UPJO (eg hydronephrosis). RESULTS Mean age was 40.7 years (range 17-80) with 70% female. UPJO occurred 44% left and 56% right, with 92% presenting with flank pain. Of 77 patients, 45 had obstruction on renal scan, with 41 (91%) having resolution of obstruction postoperatively and 44 of 45 (98%) having complete resolution of their initial symptoms. Thirty-two patients had equivocal findings with mean diuretic T1/2 of 12.6 minutes (range: 5.5-19.26) on renal scan. In this latter group, patients had significantly less of a decrease in their diuretic T1/2 postoperatively (4 vs 64 minutes, P = .018) and reported less pain resolution (53% vs 98%, P ≤.001) than group 1. CONCLUSION Many studies have demonstrated excellent success of pyeloplasty, with most series including patients meeting strict diagnostic criteria for obstruction. Our study examines outcomes in patients with clinically symptomatic UPJO and equivocal diuretic renography. In our cohort, equivocal patients were significantly less likely to have subjective resolution of symptoms than patients in the obstructed group.