PARENCHYMAL SPARING SURGERY FOR CENTRAL RENAL TUMORS IN PATIENTS WITH HEREDITARY RENAL CANCERS

X-Capsular Incision for Tumor Enucleation (X-CITE)-Technique: A Method to Maximize Renal Parenchymal Preservation for Completely Endophytic Renal Tumors

OBJECTIVE

To describe the X-Capsular Incision for Tumor Enucleation (X-CITE) technique to resect endophytic renal tumors while preserving the overlying renal parenchyma.

SUBJECTS AND METHODS

We reviewed 1-year outcomes of 12 consecutive patients with a history of bilateral or multifocal renal tumors who presented to our institution with completely endophytic renal masse(s) between August 2017 and August 2018. Endophytic tumors were resected by making an X-shaped incision in the renal capsule and developing parenchymal flaps overlying the tumor pseudocapsule. Following tumor enucleation, the overlying parenchymal flaps were reapproximated.

RESULTS

Median follow up was 19.9 months (range 10.6-14.9). Most patients also had additional exophytic tumors with a median of 5 renal tumors removed per operation with a median largest renal tumor size of 3.2 cm. No intraoperative or postoperative complications occurred. There was no decline in renal function after surgery when comparing median pre- and 12-month postoperative eGFR (94.5 vs 91.5, P= 0.18).). Postoperative nuclear mercaptoacetyltriglycine (MAG-3) renal scans demonstrated equal differential kidney function after surgery. Limitations include short-term follow-up and referral bias at center specializing in multi-focal kidney surgery.

CONCLUSION

The X-Capsular Incision for Tumor Enucleation technique is feasible, safe and effective with minimal collateral damage in the treatment of completely endophytic renal masses. Further investigation should identify which patients may benefit from this procedure and explore intermediate and long-term outcomes.

Intraoperative ultrasonography in laparoscopic partial nephrectomy for intrarenal tumors

Objective

To evaluate the feasibility and efficacy of intraoperative ultrasonography in laparoscopic partial nephrectomy (LPN) for intrarenal tumors.

Patients and methods

All patients who underwent LPN for renal tumors in our institution from January 2010 to October 2016 were assessed retrospectively. Patients were divided into two groups, the first with totally intrarenal tumors (TIT group), defined as a solid renal mass with no exophytic element on both preoperative and intraoperative evaluations, and the second with exophytic tumors (control group). General information and perioperative data of the two groups were compared, including tumor characteristics, operative time, estimated blood loss, warm ischemia time and pathological findings. Intraoperative laparoscopic ultrasonography (ILUS) was used to precisely locate and delineate the TIT border, as well as seeking for other suspected lesions.

Results

We identified 583 patients who underwent LPN in our center, including 46 in the TIT and 537 in the control group. All patients in the TIT group were evaluated by ILUS, and all TIT procedures were successfully performed with only one conversion to open surgery. The mean tumor sizes in the TIT and control groups were 2.42 ± 0.46 cm and 3.29 ± 1.43 cm (p < 0.001), respectively. The TIT group’s R.E.N.A.L. nephrometry score was higher than that of the control group (median 8.5 vs 6.0, p < 0.001), and their mean operation times were 127.2 ± 16.0 min and 120.1 ± 19.2 min, respectively. Mean estimated blood loss was higher in the TIT than in the control group (161.3 ml vs 136.6 ml, p = 0.003). Mean warm ischemia time differed in the TIT and control groups (22.2 ± 6.4 vs 20.6 ± 4.7 min, p = 0.105), but not significantly. Rates of open conversion and positive margins, as well as rates of major postoperative complications, pathological findings, and 1-month changes in renal function, were similar in the two groups.

Conclusion

Intraoperative ultrasonography is technically feasible in patients undergoing LPN for TITs. This method may reduce the need for radical nephrectomy in patients with endogenic renal masses.

Renal functional outcomes after robotic multiplex partial nephrectomy: the National Cancer Institute experience with robotic partial nephrectomy for 3 or more tumors in a single kidney

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.

The Zhongshan score: a novel and simple anatomic classification system to predict perioperative outcomes of nephron-sparing surgery

In the zero ischemia era of nephron-sparing surgery (NSS), a new anatomic classification system (ACS) is needed to adjust to these new surgical techniques. We devised a novel and simple ACS, and compared it with the RENAL and PADUA scores to predict the risk of NSS outcomes. We retrospectively evaluated 789 patients who underwent NSS with available imaging between January 2007 and July 2014. Demographic and clinical data were assessed. The Zhongshan (ZS) score consisted of three parameters. RENAL, PADUA, and ZS scores are divided into three groups, that is, high, moderate, and low scores. For operative time (OT), significant differences were seen between any two groups of ZS score and PADUA score (all P < 0.05). For ZS score, patients with moderate and high scores had longer warm ischemia time (WIT) and greater increase in SCr compared with low score (all P < 0.05). What is more, the differences between moderate and high scores classified by ZS score were borderline but trending toward significance in WIT (P = 0.064) and increase in SCr (P = 0.052). Interestingly, RENAL showed no significant difference between moderate and high complexity in OT, WIT, estimated blood loss, and increase in SCr. Compared with patients with a low score of ZS, those with a high or moderate score had 8.1-fold or 3.3-fold higher risk of surgical complications, respectively (all P < 0.05). As for RENAL score, patients with a high or moderate score had 5.7-fold or 1.9-fold higher risk of surgical complications, respectively (all P < 0.05). Patients with a high or moderate score of PADUA had 2.3-fold or 2.8-fold higher risk of surgical complications, respectively (all P < 0.05). In the ROC curve analysis, ZS score had the greatest AUC for surgical complications (AUC = 0.632) and the conversion to radical nephrectomy (AUC = 0.845) (all P < 0.05). In conclusion, the ability of ZS score to predict the surgical complexity and surgical complications of NSS is better than RENAL and PADUA scores. ZS score could be used to reflect the surgical complexity and predict the risk of surgical complications in patients undergoing NSS.

Renal masses herniating into the hilum: technical considerations of the "ball-valve phenomenon" during nephron-sparing surgery

OBJECTIVES

To describe our technique to recognize and resect renal tumors "ball-valving" into the sinus. Partial nephrectomy (PN) offers a functional advantage over radical nephrectomy for many cases of localized renal cell carcinoma. However, PN is underutilized particularly in anatomically challenging cases. Often unrecognized is the tendency for central renal tumors to herniate into the renal sinus.

METHODS

From our prospective kidney cancer database, we identified 36 patients who underwent open, laparoscopic, or robotic PN for solitary localized renal cell carcinoma herniating into the renal sinus.

RESULTS

Axial and reformatted radiographs were reviewed for all renal hilar lesions. Intraoperative techniques include hilar dissection, establishment of a sinus plane allowing tumor and parenchymal retraction, reduction of the tumor out of the sinus, resection, and repair. Mean preoperative lesion size was 3.8 cm. Indications for PN included 15 of 36 (42%) absolute, 13 of 36 (36%) relative, and 2 of 36 (6%) reoperative PN. No procedure was converted to radical nephrectomy. Of the 36 PN, 5 (14%) were performed using a minimally invasive approach and no minimally invasive surgery procedures were converted to open. No patient required renal replacement.

CONCLUSIONS

Recognition of the tendency for hilar masses to herniate or "ball-valve" into the renal sinus is essential for effective PN of central tumors. By using our technique, we have demonstrated success in nephron-sparing surgery with minimal intraoperative complications and favorable postoperative outcomes in patients with central tumors herniating into the renal sinus.

Hereditary kidney cancer: unique opportunity for disease-based therapy

Kidney cancer is not a single disease; it is comprised of several different types of cancer, each with a different histology, with a different clinical course, caused by a different gene, and responding differently to therapy. The VHL gene is the gene for the hereditary cancer syndrome, von Hippel-Lindau, as well as for the common form of sporadic, noninherited, clear cell kidney cancer. Understanding the VHL-hypoxia inducible factor (HIF) pathway has provided the foundation for the development of several agents targeting this pathway, such as sunitinib, sorafenib, and temsirolimus. Hereditary papillary renal carcinoma (HPRC) is a hereditary renal cancer syndrome in which affected individuals are at risk for the development of bilateral, multifocal, type 1 papillary renal cell carcinoma. The genetic defect underlying HPRC is MET, the cell surface receptor for hepatocyte growth factor. Mutations of MET also have been identified in a subset of tumors from patients with sporadic type 1 papillary renal cell carcinoma (RCC). Clinical trials targeting the MET pathway are currently underway in patients with HPRC and in patients with sporadic (nonhereditary) papillary kidney cancer. The BHD gene (also known as folliculin or FLCN) is the gene for Birt-Hogg-Dube syndrome, an autosomal-dominant genodermatosis associated with a hereditary form of chromophobe and oncocytic, hybrid RCC. Preclinical studies are underway targeting the BHD gene pathway in preparation for clinical trials in Birt-Hogg-Dube and sporadic chromophobe RCC. Patients with hereditary leiomyomatosis RCC (HLRCC) are at risk for developing cutaneous and uterine leiomyomas and a very aggressive type of RCC. HLRCC is characterized by germline mutation of the Krebs cycle enzyme, fumarate hydratase (FH). Studies of the tricarboxylic acid cycle and the VHL-HIF pathways have provided the foundation for therapeutic approaches in patients with HLRCC-associated kidney cancer as well as other hereditary and sporadic forms of RCC.

[Preventing urinary fistulas in laparoscopic renal conservative parenchyma surgery with purified bovine serum albumin and glutaraldehyde (bioglue). Initial outcomes]

INTRODUCTION

Urinary fistulas remain an important conservative renal parenchyma surgery (CRPS) complication, especially in central or hiliar tumours and bigger than 4 cm. Herein we present our initial experience preventing fistulae with bioglue (Criolife Inc GA, USA) on laparoscopic CRPS in which urinary tract was opened.

PATIENTS AND METHODS

We performed 5 laparoscopic CRPS between September 2005 and February 2006 in which urinary tract was necessarily opened. Previous uretheral catheter, transperitoneal approach, selective arterial control, tumorectomy or heminephrectomy, suturing urinary tract and renal parenchyma and bioglue administration was performed.

RESULTS

Median follow up time was 8.2 months (6-12 months). Median surgery time was 138 minutes (105-180 minutes) with a median ischemia time of 45 minutes (35-60). Uretheral catheter was removed before second post-op day in all cases. Average discharged day was 3.8 (3-5 days). One patient required intraoperative transfusion due to breaking Rummel tourniquet and one arterio- calyceal fistula on tenth day pos-op that required selective embolization remained the worst complication. Neither urinary fistulas nor urinomas were reported.

CONCLUSIONS

Uretheral cathetesim, suturing urinary tract and parenchyma in an independent fashion and applying some kind of surgical adhesive such as bioglue seems to reduce the urinary fistulae risk in laparoscopic CRPS.

Nephron-sparing surgery and percutaneous biopsies in renal-cell carcinoma: a global impression among endourologists

BACKGROUND AND PURPOSE

On the one hand, nephron-sparing surgery (NSS) in small renal tumors is a safe and effective alternative to radical nephrectomy. On the other hand, the role of preoperative percutaneous needle biopsies (PNB) remains controversial. The purpose of this study was to evaluate the global current use of NSS in the treatment of renal-cell carcinoma (RCC) and the use of PNB among endourologists.

MATERIALS AND METHODS

One thousand questionnaires were distributed during the 23rd World Congress of Endourology and SWL. Six questions regarding NSS and two questions regarding PNB were presented. Two hundred twenty-two questionnaires were returned.

RESULTS

Of the respondents, 86.6% perform NSS for small renal tumors, whereas 13.4% perform only radical nephrectomies; 7.5% will consider NSS only in patients with a solitary kidney, and 0.5% will never consider NSS. The techniques for NSS, in descending order of preference, are partial nephrectomy, enucleation, cryoablation, radiofrequency ablation, and high-intensity focused ultrasound. The mean and maximum diameter of the tumor in patients with a normal contralateral kidney for which the urologists perform NSS is 4.0 cm. For a centrally located tumor, NSS is an option for 27.2% of the respondents. Regarding PNB in patients with suspicion of RCC, 55.9% of respondents never obtain renal biopsies in the preoperative assessment and 41.8% obtain them only in rare cases. The majority (90%) prefer histologic over cytologic biopsies.

CONCLUSIONS

Nephron-sparing surgery is evolving to a global worldwide standard treatment for small renal tumors. Percutaneous needle biopsy remains a highly debated procedure.

Laparoscopic partial nephrectomy for centrally located renal tumors

PURPOSE

LPN is frequently reserved for small, peripherally located tumors. Centrally located tumors typically require complex intracorporeal suturing and reconstruction with hilar clamping, which is a laparoscopically advanced maneuver given the constraints of renal ischemia. We retrospectively compared our experience with central vs peripheral tumors treated with LPN.

MATERIALS AND METHODS

Between January 2001 and March 2004, 363 patients underwent LPN for tumor. The tumor was located centrally in 154 patients and peripherally in 209. Central tumors were defined as tumors centrally extending into the kidney in direct contact with or invading into the pelvicaliceal system and/or renal sinus on preoperative 3-dimensional computerized tomography. Lesions with no contact with the pelvicaliceal system were classified as peripheral. Preoperative, intraoperative, postoperative and pathological data were compared.

RESULTS

Central tumors were larger (median 3 vs 2.4 cm, p < 0.001) and had larger specimens at surgery (median 43 vs 22 gm, p < 0.001) than peripheral tumors. Although blood loss was similar (median 150 cc), central tumors required longer warm ischemia time (median 33.5 vs 30 minutes, p < 0.001), operative time (median 3.5 vs 3 hours, p = 0.008) and hospital stay (median 67 vs 60 hours, p < 0.001). A positive cancer margin occurred in 1 patient per group. Median postoperative serum creatinine was similar (1.2 vs 1.1 mg/dl). Intraoperative and late postoperative complications were comparable. However, more early postoperative complications occurred in the central group (6% vs 2%, p = 0.05).

CONCLUSIONS

LPN for central tumors can be performed safely by an experienced laparoscopic surgeon with perioperative outcomes comparable to those of peripheral tumors. Given the requisite laparoscopic expertise, indications for LPN should be expanded to include centrally located tumors.

Partial nephrectomy with perfusion cooling for imperative indications: a 24-year experience

OBJECTIVE

To report our 24-year experience with open nephron-sparing surgery for renal tumours, using cold ischaemia achieved by renal artery perfusion, as partial nephrectomy for imperative indications is a surgical challenge.

PATIENTS AND METHODS

From 1980 to 2004, open partial nephrectomy was performed in 717 patients; of these, 65 (9.1%) with a solitary kidney, synchronous bilateral tumours or renal failure in the opposite kidney (imperative indication) had surgery under cold ischaemia, achieved by continuous perfusion of Ringer's lactate at 4 degrees C through the renal artery, which was clamped and cannulated. The tumour was resected in a bloodless field, with biopsies taken from the tumour bed. Focusing on patients with an imperative indication and cold perfusion, we report our perfusion technique, and the ischaemia time, complication rate and cancer-specific survival rate of these patients.

RESULTS

The mean (SD, range) operative duration was 132 (103, 91-252) min and ischaemia time 49 (37, 31-71) min. The most common complications were postoperative haemorrhage in 19%, urinary fistula in 8% and acute renal failure in 6% of patients. There were no specific complications related to the perfusion technique (renal artery stenosis, renal artery or vein thrombosis). The mean (SD, range) long-term follow-up of 95 (71, 4.3-231) months showed increased but constant creatinine values (95 micromol/L before, 182 micromol/L after surgery; P < 0.05) with no need for long-term dialysis. The tumour-specific survival rate was 94%, 76% and 76% after 1, 5 and 10 years, respectively.

CONCLUSIONS

Partial nephrectomy under cold ischaemia remains reserved for selected patients with renal tumours with an imperative indication. The technique provides excellent intraoperative visibility in an absolutely bloodless field, allows surgery with no pressure of time, and makes ex vivo workbench surgery with autotransplantation unnecessary. Perfusion cooling allows good tumour-specific long-term results, with stable residual kidney function sufficient to prevent dialysis.