Renal cell carcinoma: modern surgical approach

Transition from laparoscopic to robotic partial nephrectomy: the learning curve for an experienced laparoscopic surgeon

The transition from laparoscopic partial nephrectomy to robotic partial nephrectomy was found to be too rapid for an experienced laparoscopic surgeon.

Background:

The complexity of laparoscopic partial nephrectomy (LPN) has prompted many laparoscopic surgeons to adopt robotic partial nephrectomy (RPN) for the treatment of small renal masses. We assessed the learning curve for an experienced laparoscopic surgeon during the transition from LPN to RPN.

Methods:

We compared perioperative outcomes of the first 20 patients who underwent RPN to the last 18 patients who underwent LPN by the same surgeon (MAP). Surgical technique was consistent across platforms. The learning curve was defined as the number of cases required to consistently perform RPN with shorter average operative times (OT) and warm ischemia times (WIT), as compared to the last 18 LPN. A line of best fit aided graphical interpretation of the learning curve on a scatter diagram of OT versus procedure date.

Results:

The 2 groups had comparable preoperative demographics and tumor histopathology. No patients in either group had a positive surgical margin. There was a downward trend in both OT and WIT during the RPN learning curve. After the first 5 RPN cases, the average OT reached the average OT of the last 18 LPN cases. The average OT of the first 5 RPN patients was 242.8 minutes, compared with the average OT of the last 15 RPN patients of 171.3 minutes (P=0.011).

Conclusion:

The transition from LPN to RPN is rapid in an experienced laparoscopic surgeon. There were no significant differences in WIT, estimated blood loss, or length of hospital stay between LPN and RPN. RPN achieved a similar OT as LPN after 5 procedures.

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.

Optimizing Renal Cortical Neoplasm Tissue Sampling Through a Modified Biopsy Technique: Laboratory Experience and Initial Clinical Experience

OBJECTIVES

We evaluated 11 currently available biopsy devices using a standard and a novel renal biopsy technique in a porcine model. We then applied our laboratory findings to clinical practice to improve our biopsy results during laparoscopic renal cryoablation procedures.

METHODS

A total of 11 biopsy devices were applied to live porcine renal tissue using two different techniques. In groups 1 and 2, the biopsy devices were deployed external to the renal tissue and in a standard manner after insertion into the renal tissue, respectively. Ten biopsies were performed for each condition and with each device. The biopsy quality metrics included sample core length and width and number of glomeruli and vessels in each sample. Subsequently, we confirmed our laboratory finding regarding the optimal biopsy technique during 10 sequential laparoscopic renal cryoablation procedures. During these procedures, each renal mass underwent the standard and modified biopsy techniques.

RESULTS

In the animal investigation, a total of 220 biopsies were performed. Regarding the biopsy technique, the mean core length for groups 1 and 2 was 7.32 and 4.91 mm (P <0.01) and the mean number of glomeruli was 7.6 and 4.2 (P <0.01), respectively. Clinically, 10 patients successfully underwent renal cryoablation in conjunction with the two renal biopsy groups. In all 10 cases, between the two biopsies, a histopathologic diagnosis was successfully obtained. The preablation standard and preablation modified biopsy technique established a diagnosis 7 of 10 and 9 of 10 times, respectively.

CONCLUSIONS

Our preliminary laboratory and clinical data have demonstrated the effectiveness and safety of the modified biopsy technique.

Energieablative Therapie von Nierentumoren

Solid renal tumours with a diameter <4 cm may be effectively cured by partial nephrectomy but this is associated with a complication rate of 15-20%. In addition, these tumours are more frequently diagnosed in the elderly (<70 years) and 26% are aggressive G3 and potentially hazardous tumours. Since these tumours are frequently unifocal, spherical, peripherally located and easily accessible for minimally invasive approaches, energy ablative techniques are attractive less invasive therapeutic options. These tumours may be treated by freezing (cryoablation) or by heat (radiofrequency ablation, high intensified focused ultrasound). Cryoablation seems to be the most reliable technique with a 1.6% recurrence rate over 3 years follow-up but only 1.8% complications. Conversely skipping renders RFA unreliable in highly vascularised tumours >3 cm with 23% vital tumours to be found at histological work-up. Laparoscopic HIFU is still experimental. Percutaneous techniques are less effective as compared with laparoscopy with recurrence rates ranging between 13-21% (cryoablation) and 14-18% (RFA). In addition, oncological follow-up relies solely on radiological measurements, frequently without histological verification thus making percutaneous techniques unpredictable.

Imaging findings after minimally invasive nephron-sparing renal therapies

With the trend towards minimally invasive and nephron-sparing surgery for renal masses, laparoscopic partial nephrectomy and energy ablative techniques have become common approaches to treat low-stage tumours. Complications following such techniques are occasional, especially for ablation techniques. This review illustrates the imaging of these complications and of tumour recurrence, with the conclusion that imaging plays an important role in their diagnosis, and in the infrequent situation that intervention is needed, helps to plan subsequent management.

Nephron-Sparing Surgery for Renal Tumours: Acceleration and Facilitation of the Laparoscopic Technique

OBJECTIVE

Present our surgical technique for and experience with laparoscopic partial nephrectomy (LPN) for renal tumours during warm ischaemia.

METHODS

Twenty-five patients underwent LPN during warm ischaemia via a transperitoneal four-trocar approach. Mean tumour size was 26.2+/-7.3mm (range: 11-39 mm). Sixteen tumours were exophytic, 7 endophytic, and 2 central. The renal vessels were secured by an umbilical tape and occluded by a self-made Rumel tourniquet. Tumours were excised with a cold Endo-shear. The interstitial tissue and collecting system was closed using a running suture secured by two resorbable clips. Parenchymal edges were approximated using a running suture over a haemostatic bolster. The threads were secured by non-resorbable clips. During follow-up, renal function was evaluated by determination of serum creatinine, (99m)Tc-mercaptoacetyltriglycine scintigraphy, and parenchymal transit time.

RESULTS

Mean ischaemia time was 28.9+/-5.2 min (range: 19-40 min) and the mean blood loss was 177.4+/-285.5 ml (range: 50-1500 ml). No intraoperative complications occurred and no patient needed conversion to open surgery. Surgical margins were negative in all patients. One postoperative surgical-related perirenal haematoma occurred, which was treated conservatively (no transfusions required). None of the patients had a urinary leak. During a mean follow-up of 6.2 mo (range: 1-15 mo), none of the patients had local or port-site recurrence or distant metastasis. Parenchymal transit time was increased in 1 of 10 investigated patients (ischaemia time: 26 min), indicating ischaemic parenchymal damage.

CONCLUSION

Our technical refinements for LPN during warm ischaemia have widened indications to more complex tumours. The use of clips rather than knot tying made the procedure easier and faster and allowed completion of the suturing during an acceptable warm ischaemia time. The self-made Rumel tourniquet is safe and efficient for vessel control and occlusion. These improvements increase feasibility so that LPN can be used by more laparoscopic urologic surgeons.

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.

Handling and Reporting of Tumor-Containing Kidney Specimens

The pathologic features of RCC are the most valuable factors in predicting the prognosis and for planning surveillance and treatment protocols. Urologists and pathologists should optimize approaches in handling tumor-containing kidney specimens to allow for the best evaluation and reporting of such specimens. A pathologic report of a tumor-containing kidney specimen should include all established or potential prognostic factors, especially tumor types, size, grade, information for pathologic staging, and status of the surgical margin.

Retroperitoneoscopic radical and partial nephrectomy in the patient with cirrhosis

PURPOSE

In patients with cirrhosis and a renal mass options may be limited by medical disease and the surgical difficulties associated with portal hypertension. We describe a retrospective review of patients with cirrhosis with renal masses who underwent radical or partial nephrectomy through a retroperitoneoscopic approach.

MATERIALS AND METHODS

Ten consecutive patients, including 4 men and 6 women, with cirrhosis, of whom 2 had undergone liver transplantation, underwent radical (7) or partial (3) nephrectomy for a total of 5 right and 5 left renal neoplasms via the retroperitoneoscopic approach at our institution from March 2002 to February 2004. Recovery data were prospectively obtained and other information was gathered retrospectively from the medical record.

RESULTS

Average patient age was 58 years and average American Society of Anesthesiology score was 2.8. Average renal tumor size for radical and partial nephrectomy was 4.6 (range 2.9 to 7) and 1.8 cm (range 1.3 to 2.3), respectively. Operative time was 140 to 315 minutes (median 172) and estimated blood loss was 100 to 5,000 ml (median 225). One patient required open conversion due to hemorrhage from left portosystemic venous communications. Mean postoperative hospitalization was 1.5 days (range 1 to 6).

CONCLUSIONS

Although retroperitoneoscopic surgery avoids many surgical dangers associated with portal hypertension and it is our preferred approach to renal surgery in patients with cirrhosis, significant portosystemic venous communications exist in the retroperitoneum, especially on the left side, and they still lead to substantial blood loss in some patients.

LAPAROSCOPIC PARTIAL NEPHRECTOMY TECHNIQUES: DEVELOPMENTS AND TRANSLATION

PURPOSE

Laparoscopic partial nephrectomy has recently emerged as a potential surgical option for select renal masses. Several new techniques and devices that may aid in laparoscopic partial nephrectomy are reviewed.

MATERIALS AND METHODS

I review several techniques studied and/or developed in our laboratory. Each technique was evaluated for effectiveness in the porcine model and is in translation to clinical practice.

RESULTS

Three techniques are reviewed. A hand assisted approach incorporating renal hilar clamping with hypothermia has proven successful for complex and multifocal lesions. Recent clinical studies, and our laboratory and clinical experience have shown a saline cooled monopolar dissector to be a valuable adjunct. A new and simple technique of achieving rapid hypothermia using a pure laparoscopic approach is described.

CONCLUSIONS

Laparoscopic partial nephrectomy continues to develop as a standard of care for select renal masses. New devices and techniques will continue to make the procedure safer and reproducible.

TUMOR CAPACITANCE: ELECTRICAL MEASUREMENTS OF RENAL NEOPLASIA

PURPOSE

Studies have demonstrated that biological tissues possess unique electrical properties. We evaluate the electrical properties of renal tumors using a specialized probe with the capability of measuring intra-tissue capacitance in an ex vivo model of fresh surgically excised tissue.

MATERIALS AND METHODS

An electrical monitoring device was used to measure tissue capacitance at a frequency of 1 MHz on 34 ex vivo kidney specimens freshly obtained after surgical excision. Tissue capacitance was promptly measured in the excised tumor as well as surrounding normal parenchyma and fat. Dielectric permittivity in each tissue was calculated using the measured capacitance data. These data were compared and correlated to pathological findings.

RESULTS

The final pathology on the 34 specimens revealed 28 renal cell carcinomas (RCC), 3 oncocytomas and 3 angiomyolipomas. In patients with RCC dielectric permittivity of tumor tissue was 1.43 +/- 0.39 times greater than that of surrounding normal parenchyma (p < 0.001). The average tumor-to-normal tissue dielectric permittivity ratio for RCC was significantly greater than that for angiomyolipoma (1.43 +/- 0.39 vs 0.73 +/- 0.77, p < 0.05) but similar to that for oncocytoma (1.43 +/- 0.39 vs 1.63 +/- 0.77, p = 0.39).

CONCLUSIONS

Tissue capacitance measurements may be used to differentiate renal tumor from surrounding normal tissue. In vivo studies will ultimately determine the clinical use of this technology in localizing renal neoplasms and differentiating between malignant and benign tissues.