The evolving role of partial nephrectomy in the management of renal cell carcinoma

Efficacy of povidone-iodine against accidental tumor incision during nephron-sparing surgery: experimental study in patients with renal cell carcinoma

Purpose

Accidental tumor incision (ATI) can occur during nephron-sparing surgery (NSS) and correlates with recurrence and metastasis. This study investigated risk factors of intraoperative ATI in renal cell carcinoma (RCC) patients after NSS and the efficacy of povidone-iodine for ATI.

Methods

A retrospective analysis was performed on 150 consecutive stage I (pT1N0M0) RCC patients who underwent NSS at The Second Hospital of Tianjin Medical University between May 2010 and October 2015 for the causes of ATI. Furthermore, in vitro experiments investigated whether tumor cells remained on the surface of scissors and the effect of treatment with povidone-iodine on the number of remaining 786-O cells.

Results

Among the 150 cases, 15 showed ATI, of which three suffered local recurrence during a median follow-up of 56 months. Pseudocapsules, satellite nodules, and renal cystic tumors were observed in ATI cases. In vitro experiments showed that tumor cells remained on the surface of scissors after ATI during NSS and that 0.5% povidone-iodine effectively killed tumor cells in 30 minutes.

Conclusions

The probability of ATI is high in patients with complex-type RCC during NSS. ATI potentially increases the chance of metastasis and local recurrence, and 0.5% povidone-iodine kills tumor cells more effectively than distilled water.

Is It Safe to Use the Same Scissors After Accidental Tumor Incision During Partial Nephrectomy? Results of In Vitro and In Vivo Experiments

PURPOSE

When accidental tumor incision (ATI) has occurred during open partial nephrectomy (PN), scissors can be changed easily. In contrast, during laparoscopic partial nephrectomy (LPN) or robotic partial nephrectomy (RPN), it is time consuming and expensive especially during RPN to change scissors. This study investigates whether tumor cells remain on the surface of scissors after ATI during PN and investigates an alternative way to avoid changing scissors during LPN and RPN.

MATERIALS AND METHODS

We subcutaneously injected 786-O renal-cell carcinoma (RCC) cells containing enhanced green fluorescent protein (786-O/EGFP) into six mice. We incised the subsequent tumor with straight or Microline scissors. The scissor surfaces were then examined by microscopy for detection of EGFP immunofluorescence. In addition, the scissor surfaces were treated in three ways: no electrical treatment, electrical treatment of 20 W for 5 seconds, and electrical treatment of 40 W for 5 seconds.

RESULTS

Strings or dots of EGFP were detected on every scissor surface, and 786-O/EGFP cells were alive and able to proliferate in medium in 33% of the nonelectrically treated samples. However, no 786-O/EGFP cells treated with monopolar electricity survived. In another experiment, we also found that 100 786-O cells placed on scissor surfaces could not survive after the same electrical treatment.

CONCLUSIONS

RCC cells remained on scissors after ATI; however, electrical treatment eliminated tumor cells, possibly preventing recurrence or metastasis after surgery.

Estimated functional renal parenchymal volume predicts the split renal function following renal surgery

PURPOSE

The change in functional renal volume (FRV) has an absolute influence on renal function after nephrectomy (Nx) or nephron-sparing surgery (NSS). In this study, we prospectively examined whether the postoperative renal function following Nx and NSS could be accurately predicted and assessed the reproducibility of our newly developed 3-D image reconstruction system (Kashihara) to measure the FRV.

METHODS

We enrolled 98 patients who underwent Nx and 41 patients who underwent NSS from April 2006 to September 2009 to predict postoperative FRV and renal function. FRV was measured before and after (1 month and 1 year) renal surgery. The postoperative estimated glomerular filtration rate (eGFR) was predicted from the preoperative eGFR calculated from the serum creatinine (sCr) level and the ratio of the postoperative/preoperative FRV. To assess the reproducibility and accuracy of our newly developed 3-dimensional (3-D) image reconstruction system, FRV was measured by five examiners using images obtained by CT (five cases) and MRI (five cases).

RESULTS

Significant correlation was found both for FRV and for renal function between the predictive values and the actually measured values at 1 month and 1 year after surgery, not only in the Nx group, but also in the NSS group. The accuracy and reproducibility could be confirmed both with CT and MRI studies.

CONCLUSIONS

The postoperative FRV and renal function could be predicted preoperatively using a 3-D image reconstructive system, preoperative routine diagnostic imaging, and preoperative sCr level.

Renal cell carcinoma detected by preoperative kidney transplant donor examination: a case report

A 37-year-old man undertook preoperative examination for donor nephrectomy for living kidney transplantation. Computerized tomography revealed a small renal mass (1.9 cm in diameter) with contrast enhancement on his left kidney. We couldn't exclude malignant potential for the small mass. Laparoscopic left partial nephrectomy without renal artery clamp was successfully carried out to obtain pathologic diagnosis while preserving his renal function and priority as a donor. He was judged to be an inappropriate donor candidate owing to the histopathologic report suggesting clear cell carcinoma. The patient has been followed for 27 months without any evidence of recurrence.

Assessing renal function after partial nephrectomy using renal nuclear scintigraphy and estimated glomerular filtration rate

OBJECTIVE

To create a model intended to more accurately characterize renal function alteration after partial nephrectomy using a combination of renal scintigraphy and estimated glomerular filtration rate (eGFR).

METHODS

Thirty-two partial nephrectomy patients from a single center with preoperative and postoperative renal scans were reviewed. Renal scan data were used to calculate proportional eGFR in the involved kidney as a product of the percentage function of the operated kidney and total eGFR. Linear regression models were created to describe endpoints (postoperative eGFR, involved kidney percent function, proportional eGFR) as functions of clinical variables associated with kidney damage.

RESULTS

For the ipsilateral kidney, mean preoperative percent function and eGFR were 50% (SD, 4.8) and 31 mL/min/m(2) (SD, 3.4), respectively; postoperative percent function and involved kidney eGFR were 44% (SD, 9.0) and 27 mL/min/m(2) (SD, 9.0), respectively. Decreased postoperative proportional eGFR was significantly associated with increased clamp time and tumor size in univariate linear regression models. Clamp time was associated with total eGFR, where tumor size was not. Additionally, clamp time and tumor size explain more of the variation in proportional eGFR (R(2) = 0.39 and R(2) = 0.17, respectively), compared to percent effort and total eGFR.

CONCLUSION

Proportional eGFR has a stronger association with putative factors of renal dysfunction after partial nephrectomy, including clamp time and tumor size, compared to total eGFR, indicating it may be a more sensitive marker of renal function after partial nephrectomy.

Percutaneous microwave ablation or nephrectomy for VX-2 carcinoma in rabbit kidney

PURPOSE

We compared the effectiveness of percutaneous microwave ablation and radical nephrectomy for implanted VX-2 carcinoma in rabbit kidneys.

MATERIALS AND METHODS

VX-2 tumors were surgically implanted into the left lower pole parenchyma of 26 New Zealand White rabbit kidneys. At 12 days after implantation implanted rabbits were randomly assigned to 1 of 3 groups according to therapy type, including percutaneous microwave ablation, nephrectomy and no treatment. The anticancer effect and safety were compared among the groups. Histopathological changes in tumor tissue with time after microwave ablation were evaluated.

RESULTS

The survival rate in the percutaneous microwave ablation group was significantly higher than that in the no treatment group and showed no statistically significant difference compared with that in the nephrectomy group. Serum creatinine did not increase after microwave therapy but we noted a statistically significant serum creatinine increase in the nephrectomy group. Histological analysis revealed completely coagulative necrosis of the tumor in 10 of 12 rabbits (83.3%) after microwave ablation. Two rabbits died, including 1 of peritonitis in the nephrectomy group and 1 of intestinal fistula due to heat injury in the percutaneous microwave ablation group.

CONCLUSIONS

This study shows that percutaneous microwave ablation can achieve effects similar to those of radical nephrectomy. It caused no significant changes in renal function when treating implanted VX-2 renal tumors. Percutaneous microwave ablation has the potential of being a minimally invasive treatment for small renal tumors.

Imaging of kidney cancer

Advances in molecular genetics have expanded the understanding of renal cell tumors. Now it is understood that renal cortical tumors are a family of neoplasms with distinct cytogenetics and molecular defects, unique histopathologic features, and different malignant potentials. Imaging contributes to clinical management of patients with renal tumors in providing diagnostic information for tumor detection, characterization, staging, treatment planning, and follow-up.

Development of exophytic tumor model for laparoscopic partial nephrectomy: technique and initial experience

OBJECTIVES

To develop and test a porcine model to help teach the techniques needed to perform laparoscopic partial nephrectomy (LPN), which is a technically challenging procedure with necessary reconstructive skills that are difficult to transfer.

METHODS

A tumor model was created by unilateral subcapsular percutaneous injection of liquid plastic (Smooth-Cast 320) in five pig kidneys. Five Washington University urologists performed LPN and assessed the efficacy of the tumor model. Subsequently, the tumor model was evaluated as a tool for teaching LPN during the Washington University Advanced Laparoscopic and Robotic Urologic Oncology Course. Twenty-eight participants performed unilateral porcine LPN with the tumor model. Questionnaires were used to assess the utility of this tumor model.

RESULTS

Unilateral tumors were successfully created in five pigs and remained intact during all LPN procedures. Visually, the tumors appeared as white exophytic masses. Ultrasonography revealed a well-circumscribed, hypoechoic lesion and a mean diameter of 2.02 cm. The mean operative time was 32.4 minutes. In subsequent testing, 24 (86%) of the 28 participants returned the questionnaire, and 96% responded that the tumor model had enhanced their LPN learning experience. Seven course participants (29%) reported problems with hemostasis, ultrasonography, or laparoscopic instrumentation. Two tumor model-related complications occurred. During the initial evaluation, one pig experienced a fatal pulmonary embolism of the plastic. During the course, a second animal experienced extravasation of the solution into the renal collecting system.

CONCLUSIONS

For surgical education purposes, the Smooth-Cast model is an effective surgical tool for LPN. Most of the surgeons in this evaluation believed the model enhanced their learning experience.

Controlled Survival Study of the Effects of Tisseel or a Combination of FloSeal and Tisseel on Major Vascular Injury and Major Collecting-System Injury during Partial Nephrectomy in a Porcine Model

PURPOSE

We report the results of a controlled survival study in a porcine model investigating Tisseel or a combination of FloSeal and Tisseel in dealing with vascular and collecting-system injury during partial nephrectomy.

MATERIALS AND METHODS

We performed an open right lower-pole partial nephrectomy on 15 large female pigs. The defect was repaired using standard open techniques (N = 5; controls), Tisseel only (N = 6; group I), or FloSeal followed by Tisseel (N = 4; group II). A Jackson-Pratt drain was placed. Nephrectomy and retrograde pyelography were performed at 1 week.

RESULTS

Operative times were shorter in both study groups, achieving statistical significance in group I (P = 0.008). Warm-ischemia times were significantly improved in both study groups (P = 0.029 and P = 0.00005 in groups I and II, respectively). Time to hemostasis was significantly shorter in group II only (P = 0.002) but approached significance in Group I as well (P = 0.09). Estimated blood loss was not significantly different from the controls in either group. When Tisseel was placed alone after hilar control, hematoma formation under the Tisseel was noted on release of the hilar clamp. After 1 week, there was one urinoma and three urine leaks in the control group. In group I, there was one urinoma and four urine leaks, and there was only one urine leak and no urinomas in group II. There were no hematomas in any of the groups.

CONCLUSIONS

Tisseel alone is not adequate for either hemostasis or management of major collecting-system injury. FloSeal capped with Tisseel appears sufficient to control major vascular and collecting-system injuries without adjunctive surgical measures. A proposed technique for laparoscopic partial nephrectomy without reconstructive techniques is presented that warrants clinical study.

Laparoscopic partial nephrectomy: Technique, oncologic efficacy, and safety

Laparoscopic partial nephrectomy is emerging as an attractive approach for selected renal masses, but has been performed with significant variability in technique. The procedure's evolution, a merger of proven open techniques with applicable laparoscopic techniques and limitations, is very much a work in progress. Just as long-term follow-up for open nephron-sparing surgery for selected renal masses has demonstrated recurrence-free survival equivalent to radical nephrectomy, a few large series of laparoscopic partial nephrectomy are beginning to surface that demonstrate its clinical efficacy, although duration of follow-up is still too short to make definitive statements. This article reviews the literature and the authors share their experience and preferences in technique, derived from 100 consecutive laparoscopic partial nephrectomies and from their assessment of the acute sealant effectiveness for partial nephrectomy in a large, hypertensive, porcine model that approximates clinical situations. This review aims to assist the urologic surgeon in determining which renal tumors to approach laparoscopically and which surgical approach best fits their laparoscopic expertise.

Definitive, High-Dose-Per-Fraction, Conformal, Stereotactic External Radiation for Renal Cell Carcinoma

INTRODUCTION

Localized renal cell carcinoma is conventionally treated surgically. Preoperative and adjuvant external radiation have not improved survival. However, renal cell cancer brain metastases, although radioresistant to conventional external radiation, have been responsive to radiosurgery. The following report was compiled with information from our experience using high-dose-per-fraction, conformal radiation delivered to patients who refused definitive surgery.

MATERIALS AND METHODS

Nine patients with nonmetastatic renal cell carcinomas were identified, 2 of which had bilateral renal cell cancers. Patients were treated definitively with 40 Gy in 5 fractions using conformal external radiation.

RESULTS

With a median follow up of 26.7 months, 4 of the 9 patients are alive. The survivors have a minimum follow up of 48 months. At presentation, all 4 of the survivors had tumors < or =3.4 cm in largest dimension, had clinically negative nodes, and presented no clinical evidence of penetration of Gerota fascia or renal vein extension.

CONCLUSION

High-dose-per-fraction, conformal external radiation may have a curative role for small, node-negative, organ-confined renal cell carcinomas.

Renal Masses: Quantitative Analysis of Enhancement with Signal Intensity Measurements versus Qualitative Analysis of Enhancement with Image Subtraction for Diagnosing Malignancy at MR Imaging

PURPOSE

To retrospectively compare quantitative and qualitative methods of assessing magnetic resonance (MR) imaging contrast enhancement as the basis for diagnosing renal malignancy.

MATERIALS AND METHODS

MR imaging was performed by using a gadolinium-enhanced breath-hold fat-suppressed three-dimensional T1-weighted gradient-echo sequence in 71 patients (48 men and 23 women; mean age, 62 years; age range, 26-87 years) with 93 renal lesions for which pathologic correlation was available. For quantitative measurements of enhancement, the relative increase in signal intensity values was measured by one investigator with manually defined regions of interest, and the threshold of an increase of 15% or greater was used to distinguish malignant from benign masses. For qualitative assessment, two investigators independently reviewed the subtracted images of all lesions and subjectively determined whether enhancement was present or absent. The sensitivity, specificity, and positive and negative predictive values for each method were calculated and compared. Mean (+/- standard deviation) and median values of relative enhancement were also calculated for benign and malignant lesions.

RESULTS

At pathologic analysis, 74 (80%) of the 93 lesions were malignant, and 19 (20%)-including seven oncocytomas-were benign. For diagnosing malignancy based on enhancement alone, sensitivity and specificity, respectively, were 95% (70 of 74 lesions) and 53% (10 of 19 lesions) at quantitative analysis and 99% (73 of 74 lesions) and 58% (11 of 19 lesions) at qualitative analysis. All seven oncocytomas were considered to be malignant with both methods. When the oncocytomas were excluded, specificities increased to 83% (10 of 12 lesions) and 92% (11 of 12 lesions) for the quantitative and qualitative evaluations, respectively. Three of the four malignant lesions incorrectly characterized as benign at quantitative assessment were hyperintense on unenhanced MR images; all were diagnosed correctly at qualitative evaluation.

CONCLUSION

Image subtraction enables accurate assessment of renal tumor enhancement, particularly in the setting of masses that are hyperintense on unenhanced MR images.

Laparoscopic Partial Nephrectomy Using Microwave Tissue Coagulator for Small Renal Tumors: Usefulness and Complications

OBJECTIVES

We evaluated the usefulness and complications of laparoscopic partial nephrectomy for small renal tumors using a microwave tissue coagulator without renal pedicle clamping.

METHODS

Between September 1999 and March 2003, 19 patients with small renal tumors 11 to 45 mm in diameter underwent laparoscopic partial nephrectomy without renal ischemia.

RESULTS

Six and 13 patients were treated by the transperitoneal and retroperitoneal approaches, respectively. Excluding a case with open conversion due to dense perirenal adhesions, 18 patients successfully underwent laparoscopic procedures. The mean operative time was 240 minutes with minimal blood loss in 14 patients and 100 to 400 ml in 4. In a patient, frozen sections revealed a positive surgical margin and additional resection was performed. Postoperative complications included extended urine leakage for 14 days, arteriovenous fistula and almost total loss of renal function, respectively, in a patient. With the median follow-up of 19 months, no patients showed local recurrence or distant metastasis by CT scan.

CONCLUSIONS

Laparoscopic non-ischemic partial nephrectomy using a microwave tissue coagulator may be useful for treating small renal tumors because it does not require advanced laparoscopic skill. However, the indication of this procedure should be highly selective in order to minimize serious complications secondary to unexpected collateral damage to surrounding structures.

Surgical management of renal tumors

Renal cell carcinoma is a relatively rare tumor, accounting for approximately 3% of malignancies in adults, but is the most common tumor of the kidney and the third most common tumor seen by urologists. Renal cell carcinoma is refractory to most traditional oncologic treatments, including chemotherapy, radiation therapy, and hormonal therapy. Because of recent advances in sophisticated radiologic studies, the surgeon can now make an accurate preoperative assessment of the nature and extent of kidney tumors. When evaluating renal tumors, the urologist looks for certain information to help in constructing a management plan. This article explores some of the points that contribute in the surgical decision-making.