Adam R. Metwalli

The presence of multiple tumors in an ipsilateral kidney leads to different peri-operative outcomes and increased complications. This is particularly important now that compensation is being linked to surgical outcomes. Thus it is important for urologic surgeons to clearly define what complication rates are for each type of case and clearly define how these cases differ from standard partial nephrectomies.

Introduction: Multifocal and hereditary kidney cancers often require repeated ipsilateral nephron sparing procedures with higher blood loss and complication rates compared to first time renal surgery. Consequently, many surgeons avoid minimally invasive techniques in the setting. We present the characteristics, complications, and short-term renal functional outcomes of patients who underwent a repeat robotic partial nephrectomy (rRPNx). Materials and Methods: A database was retrospectively reviewed to identify patients who underwent robotic partial nephrectomies between January 2007 and December 2013. Selection criteria for the rRPNx cohort included patients who had undergone at least two ipsilateral renal surgeries, with the second procedure being an rRPNx. All other patients comprised the initial robotic partial nephrectomy (iRPNx) group. Results: One hundred twenty-four patients who underwent robotic partial nephrectomy during the study period were identified. rRPNx constituted 26 (21%) of the total cases. Age of the rRPNx cohort was similar (p = 0.56), but number of tumors resected was two-fold greater in the rRPNx group (p = 0.44). Neither surgery time nor renal clamp time was significantly longer in either group (p = 0.18 and p = 0.65, respectively). Importantly, estimated blood loss (EBL) was significantly larger than in the iRPNx group (p = 0.01). Both groups had similar intravenous pain medication administration durations (p = 0.32), but postsurgical length of stay was greater for the rRPNx patients (p = 0.011). There were no significant differences in clavian complication rates (p = 0.17–0.39), with the exception of urine leak which occurred more frequently in the rRPNx group (p = 0.01). There was no difference in percent change in serum creatinine or estimated glomerular filtration rate (p = 0.89 and p = 0.67, respectively). Conclusions: rRPNx is safe and feasible in select patients. EBL, postoperative lengths of stay, and urine leak were the only factors significantly associated with rRPNx compared to iRPNx. Patient 3-month follow-up revealed excellent and comparable outcomes between the two groups.

Objective To identify renal function outcomes after robotic multiplex partial nephrectomy (RMxPNx), we reviewed our institutional database at the National Institutes of Health, National Cancer Institute. To our knowledge, we present the largest series of RMxPNx renal function outcomes to date. Robotic partial nephrectomy has been employed for oncologic control and to prevent dialysis dependence in hereditary multifocal renal cell carcinoma conditions. We have termed robotic surgery on a single kidney with three or more lesions a RMxPNx. Materials and methods We evaluated patients from a prospectively maintained database at a single institution (NIH/NCI) that underwent RMxPNx from 2007 to 2013. Demographic and operative data were compiled with statistical analysis with T test performed to determine renal function outcomes. Results A total of 54 patients underwent RMxPNx. Mean number of tumors removed was 8.63 (range 3–52). Mean preoperative creatinine and eGFR were 1.02 ± 0.26 mg/dL and 85.4 ± 21.5 mL/min, respectively. Postoperatively, creatinine increased from baseline by 0.45 mg/dL (p < 0.001). Similarly, a mean decrease in eGFR by 24.6 mL/min was observed (p < 0.001). At 3-month follow-up, the creatinine increase from baseline was 0.05 mg/dL (p = 0.10) and mean decrease in eGFR was 3.01 mL/min (p = 0.21). When stratifying based on preoperative CKD stages I–III, similar results were observed. Conclusion Robotic multiplex partial nephrectomy is a safe and feasible approach to patients with multifocal renal masses. These complex surgeries have a demonstrated learning curve, but this minimally invasive approach for nephron-sparing surgery allows patients to preserve renal function where they would otherwise require open surgery or a radical nephrectomy.

To identify the risk factors associated with development of postoperative elevation of creatine kinase (CK) and study its effect on renal function in patients who underwent complex multifocal partial nephrectomy (PN).

Background Carbonic anhydrase IX (CA-IX) is a potential imaging biomarker of clear cell renal cell carcinoma (ccRCC). Here, we report the results of a phase II clinical trial of a small molecule radiotracer targeting CA-IX (¹⁸F-VM4-037) in ccRCC. Methods Between October 2012 and May 2013, 11 patients with kidney masses underwent ¹⁸F-VM4-037 PET/CT prior to surgery. Dynamic imaging was performed for the first 45 min post injection and whole-body imaging was obtained at 60 min post injection. Tumors were surgically excised or biopsied within 4 weeks of imaging. Results All patients tolerated the radiotracer well with no adverse events. Ten of the 11 patients had histologically confirmed malignancy. One patient had a Bosniak Type 3 cyst with no tumor found at surgery. Two patients had extrarenal disease and 9 had tumors only in the kidney. Primary ccRCC lesions were difficult to visualize on PET alone due to high uptake of the tracer in the adjacent normal kidney parenchyma, however when viewed in conjunction with CT, the tumors were easily localized. Metastatic lesions were clearly visible on PET. Mean SUV for primary kidney lesions was 2.55 in all patients; in patients with histologically confirmed ccRCC, the mean SUV was 3.16. The time-activity curves (TAC) are consistent with reversible ligand binding with peak activity concentration at 8 min post injection followed by washout. Distribution Volume Ratio (DVR) of the lesions was measured using the Logan graphical analysis method. The mean DVR value across the 9 kidney lesions was 5.2 ± 2.8, (range 0.68–10.34). Conclusion 18F-VM4-037 is a well-tolerated PET agent that allows same day imaging of CA-IX expression. The agent demonstrated moderate signal uptake in primary tumors and excellent visualization of CA-IX positive metastases. While the evaluation of primary ccRCC lesions is challenging due to high background activity in the normal kidney parenchyma, 18F-VM4-037 may be most useful in the evaluation of metastatic ccRCC lesions.