Current Status and Advances in Nephron-Sparing Surgery

Diagnostic performance of multidetector computed tomography in the evaluation of perinephric fat invasion in renal cell carcinoma patients

PURPOSE

This study aimed to evaluate the diagnostic performance of multidetector computed tomography (MDCT) for preoperative evaluation of perinephric fat invasion in patients with renal cell carcinomas (RCCs).

METHODS

A total of 408 consecutive patients with surgically confirmed RCC who underwent MDCT were included in this study. Image analysis was first performed with axial-only CT images. A second analysis was then performed with both axial and coronal CT images. A qualitative analysis was then conducted by 2 reviewers who reached consensus. The reference standard was pathologic evaluation.

RESULTS

The areas under the curve of the receiver operating characteristic analysis were 0.786 and 0.877 for axial-only images and 0.805 and 0.836 for combined images in both readers. The area under the curve of tumor size was 0.833, a similar value to that of the reviewers. In multivariate analysis, tumor size, a linear-nodular or nodular type of fat infiltration, and an irregular tumor margin were independent predicting factors for perinephric fat invasion.

CONCLUSIONS

The MDCT shows relatively high diagnostic performance in detecting perinephric fat invasion of RCC, but suffers from a relatively low positive predictive value. Tumor size, fat infiltration with a nodular appearance, and an irregular tumor margin were predictors for perinephric invasion.

Laparoscopic partial nephrectomy: single center experience with 140 patients--evolution of the surgical technique and its impact on patient outcomes

PURPOSE

We analyzed the outcome of laparoscopic partial nephrectomy in 140 patients and defined the evolution of the operative technique and its impact on patient outcomes.

MATERIALS AND METHODS

Preoperative tumor characteristics, intraoperative parameters (blood loss, ischemia time, complication and conversion rates) and postoperative parameters (complications, surgical margins status and followup) were compared between the initial 30 patients (group 1) and the last 110 (group 2). Statistical analysis was done using the Student t test with p <0.05 considered significant. The impact of modifications in the surgical technique on the outcome of surgery is discussed.

RESULTS

Group 1 consisted of exophytic, peripherally located tumors, whereas in group 2 central and hilar tumors were also included. The 2 groups were also different regarding mean tumor size (2.6 vs 3.9 cm p <0.05), conversion rates (10% vs 2.7%, p <0.05), postoperative complication rates (urine leakage 10% vs 1.4% and reoperation 6% vs 1.8%, p <0.05) and positive margins (10% vs 3.6%, p <0.05). Mean warm ischemia time (32 vs 29 minutes) and blood loss (460 vs 510 ml) were similar (each p >0.05). Renal cell carcinoma was found in 78% and 86% of cases, respectively. Overall 7 cases (5%) had focally positive surgical margins, including 3 in group 1 and 4 in group 2. At followup no tumor recurrences were observed.

CONCLUSIONS

Laparoscopic partial nephrectomy is a challenging procedure with potentially major complications. However, accumulated experience and adherence to a standardized surgical technique translate into improved outcomes.

Current Status of Minimally Invasive Ablative Techniques in the Treatment of Small Renal Tumours

OBJECTIVES

In the current era, minimally invasive surgery using ablative techniques for the treatment of small renal tumours has become a more common and feasible treatment option. In this review, we present recent data regarding the utility of needle ablative techniques in the experimental and clinical settings.

METHODS

We performed a comprehensive evaluation of available published data from 1997 to 2006 that were identified with PubMed. Official proceedings of internationally known scientific societies held in the same time period were also assessed.

RESULTS

Two main thermoablative techniques, cryoablation (CA) and radiofrequency ablation (RFA), represent the current available minimally invasive treatments for renal cell carcinoma (RCC). CA has been more extensively studied and has gained acceptance from patients and physicians. The procedure is well tolerated by patients even with serious concomitant diseases. RFA is delivered with a monopolar alternating current. Morbidity rates for this modality remain slightly higher than those for cryotherapy. Both techniques are associated with highly successful cancer control rates at short-to-medium follow-up in patients with tumour size <3 cm. Multiple lesions can be treated simultaneously and the procedures can be repeated. However, long-term follow-up data are still lacking.

CONCLUSION

Minimally invasive ablative approaches seem to represent an attractive alternative to extirpative surgery for the treatment of small renal neoplasms in select patients. Potential developments include concepts to improve the accuracy of thermal ablation using novel imaging modalities with reduction in side-effects and optimised selection and follow-up of patients to provide at least equivalent cancer control to conventional surgery.