Nephron sparing surgery for renal cell carcinoma

Sporadic renal cell carcinoma in young adults: presentation, treatment, and outcome

OBJECTIVES

To present our institutional experience with young adult patients treated for sporadic renal cell cancer (RCC) during the past two decades. Sporadic RCC is rare in patients younger than 40 years old, accounting for only 3.4% of cases.

METHODS

A retrospective review of 101 patients with sporadic RCC between the ages of 20 and 40 years was performed. The mean age at diagnosis was 33.7 +/- 5.5 years. Tumors were discovered incidentally in 40 patients (40%) and were symptomatic in 61 (60%). Sixteen patients (16%) had distant metastasis at diagnosis. For unilateral disease, 58 underwent radical nephrectomy and 31 nephron-sparing surgery (NSS). For bilateral RCC, 2 patients underwent bilateral radical nephrectomy, 3 underwent bilateral NSS, and 7 underwent NSS on one side and a staged contralateral radical nephrectomy. The mean postoperative follow-up was 48 +/- 44 months.

RESULTS

The overall and cancer-specific 5-year survival rate was 61% and 67%, respectively. Tumor stage (P < 0.001) and grade (P < 0.001) had a significant impact on survival. Incidentally discovered tumors were less likely to develop metastases and had improved cancer-specific survival compared with symptomatic tumors (P = 0.001). The 5-year cancer-specific survival rate by pathologic stage was 88% for T1N0M0, 64% for T2N0M0, 61% for T3N0M0, and 0% for N+ and M+ (P < 0.001).

CONCLUSIONS

The results of our study show that RCC does not behave more aggressively in young adults younger than 40 years old than in older adults. The major determinants of patient survival are tumor stage and grade at presentation. Outcome is similar in select patients whether undergoing NSS or radical nephrectomy.

Cryosurgical changes in the porcine kidney: histologic analysis with thermal history correlation

Advances in minimally invasive renal cryosurgery have renewed interest in the relative contributions of direct cryothermic and secondary vascular injury-associated ischemic cell injury. Prior studies have evaluated renal cryolesions seven or more days post-ablation and postulated that vascular injury is the primary cell injury mechanism; however, the contributions of direct versus secondary cell injury are not morphologically distinguishable during the healing/repair stage of a cryolesion. While more optimal to evaluate this issue, minimal acute (< or = 3 days) post-ablation histologic data with thermal history correlation exists. This study evaluates three groups of porcine renal cryolesions: Group (1) in vitro non-perfused (n = 5); Group (2) in vivo 2-h post-ablation perfused (n = 5); and Group (3) in vivo 3-day post-ablation perfused (n = 6). The 3.4 mm argon-cooled cryoprobe's thermal history included a 75 degrees C/min cooling rate, -130 degrees C end temperature, 60 degrees C/min thawing rate, and 15-min freeze time. An enthalpy-based mathematical model with a 2-D transient axisymmetric numerical solution with blood flow consideration was used to determine the thermal history within the ice ball. All three groups of cryolesions showed histologically similar central regions of complete cell death (CD) and transition zones of incomplete cell death (TZ). The CD had radii of 1.4, 1.1, and 1.0 cm in the non-perfused, 2-h and 3-day lesions, respectively. Capillary thrombosis was present in the 2-h perfused cryolesions with the addition of TZ arteriolar/venous thrombosis in the 3-day perfused lesions. Thermal modeling revealed the outer CD boundary in all three groups experienced similar thermal histories with an approximately -20 degrees C end temperature and 2 degrees C/min cooling and thawing rates. The presence of similar CD histology and in vitro/in vivo thermal histories in each group suggests that direct cryothermic cell injury, prior to or synchronous with vascular thrombosis, is a primary mediator of cell death in renal cryolesions.

Posterior retroperitoneoscopic partial nephrectomy using microwave tissue coagulator for small renal tumors

BACKGROUND AND PURPOSE

Laparoscopic partial nephrectomy remains surgically challenging because of the potential for excessive blood loss, infection, and the development of urinary fistulas. In addition, posterior retroperitoneoscopic partial nephrectomy is not popular because of the limited space for surgical manipulation. We evaluated the usefulness of a microwave tissue coagulator in posterior retroperitoneoscopic partial nephrectomy for small posterior renal tumor.

PATIENTS AND METHODS

Posterior retroperitoneoscopic partial nephrectomy was performed without renal pedicle clamping using a microwave tissue coagulator in six patients with small posterior renal tumors.

RESULTS

The mean operative time was 136 minutes (range 78-180 minutes), and the blood loss was <20 mL. No serious operative complications occurred, and there was no significant deterioration of renal function.

CONCLUSION

Posterior retroperitoneoscopic partial nephrectomy using a microwave tissue coagulator can be a safe and less invasive method for the treatment of small posterior renal tumors.

Partial nephrectomy: the rationale for expanding the indications

BACKGROUND

We report preliminary results of partial nephrectomy for renal tumors of > or =4 cm in 39 patients with the intent of extending the indications for kidney-sparing surgery.

METHODS

From July 1989 to October 2001, 39 patients underwent a partial nephrectomy for renal cortical tumors >4 cm in maximum diameter. Fourteen (36%) had the procedure performed for essential reasons, and 25 (64%) had an elective kidney-sparing operation. We evaluated tumor location and histology, perioperative renal function, and postoperative complications.

RESULTS

There were 20 conventional clear-cell (51%), 13 papillary (33%), 4 chromophobe (10%), and 3 oncocytomas (8%) with a median tumor size of 5 cm. After a median follow-up of 13 months, 36 patients had no evidence of disease, 1 patient had died as a result of other causes, and 2 patients who had essential operations were alive with disease. Twenty-three patients (70%) maintained normal postoperative renal function. Of six patients with moderate preoperative renal dysfunction, five (83%) had no change in postoperative renal function and only one patient required short-term dialysis.

CONCLUSIONS

With careful patient selection, partial nephrectomy can be effectively used to treat patients with renal cortical tumors >4 cm in diameter. The benefits of this approach include the effective local tumor control while at the same time preserving maximum renal function.

Impact of arterial occlusion during partial nephrectomy on residual renal function: an evaluation with (99m)technetium-dimercaptosuccinic acid scintigraphy

BACKGROUND

Partial nephrectomy (PNx) has been performed with temporary renal arterial occlusion and in situ renal hypothermia (conventional PNx). However, the impact of temporary renal arterial occlusion on residual renal function has not been well assessed. To address this question, we performed renal scintigraphy with (99m)technetium-dimercaptosuccinic acid (DMSA) for the quantitative measurement of postoperative residual renal function after conventional PNx and partial nephrectomy without arterial occlusion (non-clamping PNx).

METHODS

Thirty-four patients underwent postoperative DMSA scintigraphy after PNx for renal cell carcinoma. No obvious difference in preoperative renal function between the diseased kidney and the contralateral kidney was found in any of the patients. Of these patients, 24 underwent conventional PNx, and 10 underwent non-clamping PNx. Residual renal function was evaluated using the relative DMSA uptake of the operated kidney.

RESULTS

The relative DMSA uptake of the operated kidney was 39.9 +/- 7.3% (25.1-58.8) after conventional PNx compared to 34.8 +/- 8.9% (13.5-45.5) after non-clamping PNx. This difference was not statistically significant (P = 0.15). Total ischemic time during conventional PNx had no adverse influence on the residual renal function. In the analysis of the other determinant factors influencing residual renal function, tumor size was the only significant factor that inversely correlated with the relative DMSA uptake.

CONCLUSION

Our results showed that arterial clamping during PNx has no negative impact on the functional residual capacity as long as insitu renal hypothermia is adequately performed.

Clinical use of the holmium: YAG laser in laparoscopic partial nephrectomy

PURPOSE

To report on the technique and utility of the holmium: YAG laser in performing laparoscopic partial nephrectomy (LPN).

PATIENTS AND METHODS

Three patients with indications for LPN (complex cyst, nonfunctioning lower pole, renal mass) underwent parenchymal-sparing procedures with the Ho:YAG laser. The kidney was identified using a transperitoneal laparoscopic technique. Gerota's fascia was opened, and the renal mass/nonfunctioning lower pole was resected using the laser. Settings of 0.2 J/pulse at 60 pulses/sec and 0.8 J/pulse at 40 pulses/sec were used.

RESULTS

All three procedures were performed successfully with minimal blood loss and without the need for hilar occlusion. Although the laser alone was hemostatic, fibrin glue was applied in two cases and oxidized cellulose in one case to reinforce the tissue against delayed bleeding. There were no perioperative complications, and all patients left the hospital within 3 days.

CONCLUSIONS

At high power settings, the Ho:YAG laser is an effective tool for LPN. It results in good hemostasis without the need for hilar occlusion. This technique promises to facilitate the laparoscopic management of renal tumors and nonfunctioning moieties of duplicated systems.

Nephron-sparing surgery for renal cell carcinoma

Nephron-sparing surgery (NSS) provides effective curative therapy for patients with localized renal cell carcinoma. In patients with imperative indications, it represents an alternative to renal replacement therapy. For selected patients with systemic comorbidities that threaten global renal function, NSS preserves unaffected nephrons with excellent cancer-specific survival. Elective partial nephrectomy for patients with a small (< or = 4 cm), unifocal tumor and a normal contralateral kidney is associated with a low risk (0%-3%) of local recurrence and cancer-specific survival rates of 90%-100%. Comparisons between radical and partial nephrectomy demonstrate equivalent cancer control over five years. Minimally invasive techniques of NSS are feasible but await improved technologies and long-term outcome data before they become fully acceptable treatment options.

Endoloop-assisted laparoscopic partial nephrectomy

PURPOSE

To determine the safety and feasibility of Endoloop-assisted laparoscopic partial nephrectomy in a large-animal model.

MATERIALS AND METHODS

Twelve female Yucatan mini-pigs underwent either left (N = 6) or right (N = 6) transperitoneal laparoscopic lower-pole nephrectomy following cinching of a 1-0 Vicryl suture loop (Endoloop) proximal to the resected lower pole until ischemic discoloration was achieved. The ischemic lower pole was excised with Endo-scissors and the lower pole removed using a laparoscopic bag. Follow-up involved evaluation under anesthesia with retrograde pyelography and intravenous urography and subsequent sacrifice for pathologic evaluation at 3 (N = 4), 14 (N = 4), or 60 (N = 4) days.

RESULTS

All procedures were completed successfully. In two cases, the Endoloop slipped off the retained parenchyma. Both problems were corrected immediately with no sequelae. At sacrifice, all upper-pole renal segments functioned, as shown by urography, and no urinomas or abscesses were found. In one animal, there was moderate hydronephrosis presumably secondary to ureteral scarring, and in another, mild extravasation was demonstrated on the retrograde pyelogram.

CONCLUSION

We were able to perform laparoscopic partial nephrectomy with the Endoloop safely and effectively in the current model. Modification of the Endoloop to allow more controlled pressure application may allow clinical application of this method for polar laparoscopic partial nephrectomy.

Comparison of costs and complications of radical and partial nephrectomy for treatment of localized renal cell carcinoma

OBJECTIVES

To compare the complications and costs of radical and partial nephrectomy (PN) and to investigate the impact of increasing experience on costs and complications during a 7-year period. Nephron-sparing surgery has found increasing applications in the past decade. PN has achieved similar long-term results in localized renal cell carcinoma with respect to cancer control compared with radical nephrectomy (RN). However, data are limited on the direct comparison of complications and hospital costs between these two modalities.

METHODS

A retrospective case-matched study was performed comparing 60 RNs and 60 PNs during a 7-year period with respect to complications and hospital costs. A longitudinal comparison was also performed between the various periods to assess the impact of surgical experience on these parameters.

RESULTS

The mean length of stay was 6.4 +/- 3 days in the RN group and 6.4 +/- 3.3 days in the PN group. The hospital costs were comparable between the two procedures during the observed interval. The mean operative time was 176.6 +/- 51.6 minutes for RN and 220.1 +/- 59.6 minutes for PN (P = 0.0001). This difference was accentuated during the observed period. No differences were found in the blood loss and transfusion rates between the groups. The complication rate was 3.3% and 10% for RN and PN, respectively (P = 0.2).

CONCLUSIONS

Our data suggest that RN and PN can be performed with a similar rate of complications and comparable hospital costs. This is of practical importance when comparing these modalities as treatment options for localized renal cell carcinoma.

Minimally invasive ablative approaches in the treatment of renal cell carcinoma

Ablative techniques for the treatment of renal cell carcinoma (RCC) are an extension of nephron-sparing surgery and include cryoablation, radiofrequency ablation (RFA), and high-intensity focused ultrasound (HIFU). Although experimental, these are evolving treatment modalities. The widespread use of computed tomography scans, ultrasound, and magnetic resonance imaging caused an increase in the diagnosis rate of small renal masses amenable to nephron-sparing surgery. The same imaging modalities permit interactive monitoring both during the delivery of ablative measures and at postoperative follow-up. Cryosurgery is the most studied of the ablative approaches, and clinical studies have demonstrated promising short-term results and a remarkable safety profile. Long-term studies, however, are needed in order to determine the appropriate selection criteria and to confirm a response as durable as that for partial and radical nephrectomy. More data are needed to evaluate the efficacy of RFA. Currently, preclinical results with HIFU do not justify its use for treating RCC in humans.

The changing natural history of renal cell carcinoma

PURPOSE

Our understanding of the natural history of renal cell carcinoma, the role of nephrectomy, the benefits of immunotherapy and the possibilities of new technologies are evolving and being integrated with advances in classification and staging. We reviewed the relevant literature to clarify these pertinent questions and provide a current review of the changes in the epidemiology, treatment and prognosis of patients with renal cell carcinoma.

MATERIALS AND METHODS

We comprehensively reviewed the peer reviewed literature on the current management of and results of treatment for renal cell carcinoma.

RESULTS

The incidence of and mortality from renal cell carcinoma have continuously increased during the last 50 years. Despite this increase in the number of new patients and consequently the number of deaths yearly the percent of those surviving for 5 years has notably improved. Factors related to improved survival include advances in renal imaging, earlier diagnosis, improved staging, better understanding of prognostic indicators, refinement in surgical technique and the introduction of immunotherapy approaches for advanced disease.

CONCLUSIONS

Currently patients with localized and metastatic renal cell carcinoma have had improvements in outlook and the therapeutic options available have expanded.

Laparoscopic nephron-sparing surgery for renal tumors

OBJECTIVES

To report our experience with laparoscopic nephron-sparing surgery. Because of the widespread use of ultrasonography and computed tomography, laparoscopy is becoming more and more important in the surgical management of solid renal masses. Although laparoscopic radical nephrectomy has gained wide acceptance, laparoscopic nephron-sparing surgery for renal tumors is still rarely done.

METHODS

From June 1994 to December 2000, we treated 51 patients presenting with small exophytic solid renal masses by laparoscopic wedge resection in two Austrian centers. Depending on the center, the retroperitoneal approach was used in 32 cases and the transperitoneal approach was used in 19. The mean age was 59.8 years, and the average tumor size was 2 cm in diameter. Wedge resection was performed with the UltraCision device, and hemostasis was achieved by bipolar coagulation and fibrin glue-coated cellulose.

RESULTS

All procedures were finished laparoscopically, and no conversion was necessary. The mean operating time was 132 minutes (range 70 to 300), mean blood loss 282 mL (range 20 to 800), mean postoperative hospital stay 5.8 days (range 3 to 12). The histologic findings were renal cell carcinoma in 38 patients (76%), benign disease in 12 patients (24%), and secondary tumor in 1 patient. Neither distant nor local recurrences were observed by the last follow-up date. Three cases of urinary leakage and one of postoperative bleeding occurred.

CONCLUSIONS

Laparoscopic nephron-sparing surgery for renal tumors is a technically difficult procedure, but excellent tumor control can be achieved. Nevertheless, currently, this procedure should be concentrated in centers with a high experience in laparoscopic surgery.

The changing natural history of renal cell carcinoma

PURPOSE

Our understanding of the natural history of renal cell carcinoma, the role of nephrectomy, the benefits of immunotherapy and the possibilities of new technologies are evolving and being integrated with advances in classification and staging. We reviewed the relevant literature to clarify these pertinent questions and provide a current review of the changes in the epidemiology, treatment and prognosis of patients with renal cell carcinoma.

MATERIALS AND METHODS

We comprehensively reviewed the peer reviewed literature on the current management of and results of treatment for renal cell carcinoma.

RESULTS

The incidence of and mortality from renal cell carcinoma have continuously increased during the last 50 years. Despite this increase in the number of new patients and consequently the number of deaths yearly the percent of those surviving for 5 years has notably improved. Factors related to improved survival include advances in renal imaging, earlier diagnosis, improved staging, better understanding of prognostic indicators, refinement in surgical technique and the introduction of immunotherapy approaches for advanced disease.

CONCLUSIONS

Currently patients with localized and metastatic renal cell carcinoma have had improvements in outlook and the therapeutic options available have expanded.

Current concepts in the diagnosis and management of renal cell carcinoma: role of multidetector ct and three-dimensional CT

Renal cell carcinoma is the most common primary tumor of the kidney, with more than 30,000 new cases diagnosed in the United States each year. With the widespread use of cross-sectional imaging, many tumors are detected incidentally. Single- and multidetector computed tomography (CT) have helped refine the diagnostic work-up of renal masses by allowing image acquisition in various phases of renal enhancement after intravenous administration of a single bolus of contrast material. The scanning protocol should include unenhanced CT followed by imaging during the corticomedullary and nephrographic phases of enhancement. The nephrographic phase is the most sensitive for tumoral detection, while the corticomedullary phase is essential for imaging the renal veins for possible tumoral extension and the parenchymal organs for potential metastases. Knowledge of the tumoral stage at the time of diagnosis is essential for prognosis and surgical planning. The accuracy of CT for staging has been reported to reach 91%, with most staging errors related to the diagnosis of perinephric extension of tumor. Three-dimensional CT provides the urologist with an interactive road map of the relationships among the tumor, the major vessels, and the collecting system. This information is particularly critical if the tumor extends into the inferior vena cava and if nephron-sparing surgery is being planned.

Perfusion-modulated MR imaging-guided radiofrequency ablation of the kidney in a porcine model

OBJECTIVE

This study was performed to test the hypothesis that temporary renal ischemia will result in increased thermal lesion size during radiofrequency thermal ablation in the kidney.

MATERIALS AND METHODS

Twelve kidneys were treated in six pigs that were placed under general anesthesia in the MR suite, using a 0.2-T open C-shaped MR imaging system. A 4-cm-long, 14-mm-diameter balloon catheter was placed into the aorta using a transfemoral approach, and the balloon was positioned proximal to the renal arteries via guidance with MR imaging. A 2-cm exposed-tip MR-compatible 17-gauge radiofrequency electrode was placed into one kidney under MR fluoroscopy using fast imaging with steady-state free precession (FISP) sequences. Thermal ablation was performed with the electrode tip temperature maintained at 90 +/- 2 degrees C for 10 min. This procedure was repeated in the contralateral kidney. The balloon was inflated during one ablation. Postablation images were obtained, the pigs were sacrificed, and both kidneys of each animal were harvested for pathologic correlation.

RESULTS

Technical success was achieved in all animals. The lesion measured 14.2 +/- 2.2 mm (mean +/- standard deviation) for the ischemic kidney versus 8.0 +/- 2.6 mm in the normally perfused kidney (p = 0.00002). No significant complications were noted. In all images, thermal lesions displayed low signal intensity with a sharp rim of high signal intensity best visualized using short tau inversion recovery (STIR) sequences with a mean accuracy of 1.3 +/- 1.2 mm when compared with pathologic findings and a mean contrast-to-noise ratio of 4.9 +/- 2.5.

CONCLUSION

We accept the hypothesis that temporary renal ischemia leads to a significantly increased radiofrequency ablation lesion size. We conclude that catheter-based balloon perfusion reduction is feasible, that the procedure does not lead to major complications, and that it can be performed using MR imaging as the sole imaging modality.

LAPAROSCOPIC PARTIAL NEPHRECTOMY WITH A MICROWAVE TISSUE COAGULATOR FOR SMALL RENAL TUMOR

PURPOSE

Laparoscopic partial nephrectomy is a challenging procedure due to the risk of excessive bleeding. We evaluated the usefulness of a microwave tissue coagulator during laparoscopic partial nephrectomy for small renal tumor.

MATERIALS AND METHODS

From January to July 2000, 6 patients with small renal tumors, from 11 to 25 mm. in diameter, underwent laparoscopic partial nephrectomy with a microwave tissue coagulator without renal pedicle clamping. There were 4 patients who underwent the transperitoneal and 2 who underwent the retroperitoneal approaches.

RESULTS

Mean operating time was 186 minutes (range 131 to 239), and blood loss was minimal. Complications were mild and tolerable, and there was no significant deterioration of renal function.

CONCLUSIONS

Laparoscopic partial nephrectomy with a microwave tissue coagulator is a useful and less invasive method for treatment of select small renal tumors. Long-term followup of patients is warranted to determine the potential for cancer control with this method.

Laparoscopic partial nephrectomy and wedge resection for the treatment of renal malignancy

The widespread use of abdominal ultrasonography, CT, and MRI has led to an increase in the number of incidentally detected renal masses, some of which are malignant. Numerous studies suggest that partial nephrectomy or wedge resection of these lesions yield cure rates similar to those obtained with radical surgery. Laparoscopic nephron-sparing surgery is one of the more challenging minimally invasive surgical techniques, and its use is largely restricted to specialized medical centers. The techniques and available results are described.

Renal cell carcinoma

Several renal cell carcinoma (RCC) prognostic factors show promise, including K1-67, p53/mdm-2, and vascular endothelial growth factor. The combination of increased incidence of RCC and diagnosis during earlier stages has generated interest in local therapeutic options. Nephron-sparing surgery and laparoscopic nephrectomy continue to gain support and may become the standard of care in select patients. Standard therapy for metastatic disease continues to be cytokine-based therapy with little benefit gained from adding granulocyte-macrophage-colony-stimulating factor, retinoic acid, or adoptive immunotherapy. The addition of chemotherapy, such as capecitabine, floxuridine, and vinblastine, may increase the effectiveness of immunotherapy; nonmyeloablative stem cell transplantation has shown early promise in metastatic disease.

Clinical experience with open renal cryoablation

OBJECTIVES

To evaluate the safety and efficacy of open renal cryoablation of small solid renal masses, since the delivery of freezing temperatures has been shown to effectively ablate solid neoplasms of the liver, uterus, and prostate.

METHODS

A total of 29 patients were treated with open renal cryoablation since December 1996 and followed up to evaluate the treatment safety and initial radiographic response.

RESULTS

The median preoperative lesion size was 2.2 cm, with 22 solid renal masses and 7 complex renal lesions. Five serious adverse events occurred in 5 patients, with only one event directly related to the procedure. One patient experienced a biopsy-proven local recurrence, and 91.3% of patients (median follow-up 16 months) demonstrated a complete radiographic response with only a residual scar or small, nonenhancing cyst.

CONCLUSIONS

Open renal cryoablation appears to be a safe technique for the in situ destruction of solid or complex renal masses. However, inadequate freezing of renal cell carcinoma may result in local disease persistence. The expected slow growth rate of small renal cancers necessitates prolonged radiologic follow-up. Continued clinical research is required before renal cryoablation can be considered an acceptable curative treatment for renal cancer.

Laparoscopic partial nephrectomy and wedge resection

Partial nephrectomy is a more challenging operation than radical or simple nephrectomy, primarily because of the risk of complications such as bleeding. This problem is even more troublesome with minimally invasive approaches because of the dearth of effective hemostatic instruments and supplies. The location of the lesion determines whether a transperitoneal or a retroperitoneal route will be employed. Centrally located or anterior renal lesions generally are approached transperitoneally whereas peripheral lateral or posterior lesions are accessed by retroperitoneoscopy. The Harmonic Scalpel with slow cutting and high coagulation settings is useful for incising the renal capsule and parenchyma. The argon beam coagulator is helpful to stop any persistent bleeding. The few reported series of laparoscopic partial nephrectomy indicate considerably longer operative times than are needed for open surgery and hospitalization of upwards of 5 days, largely to monitor drainage and urine leakage. It is hoped that this advanced laparoscopic technique will become more user friendly with further developments in techniques and instrumentation to provide patients with the expected benefits of minimally invasive surgery.

Laparoscopic partial nephrectomy. The European experience

Laparoscopic partial nephrectomy is technically difficult but oncologically effective. The operation should be performed in centers with expertise. Hemostasis can be achieved using bipolar coagulation and fibrin glue-coated cellulose. Further studies will determine whether less invasive alternatives (focused ultrasound, cryotherapy) will meet the high standard of open (or laparoscopic) nephron-sparing surgery for small renal cell carcinoma.

Comparison of complications after radical and partial nephrectomy: results from the National Veterans Administration Surgical Quality Improvement Program

OBJECTIVE

To determine whether radical nephrectomy causes less morbidity, less mortality and is associated with a shorter hospital stay than is partial nephrectomy.

PATIENTS AND METHODS

A total of 1885 nephrectomies (1373 radical and 512 partial) conducted between 1991 and 1998 in the Department of Veterans Affairs (VA) National Surgical Quality Improvement Program were evaluated. Using multivariate analyses, outcomes were risk-adjusted based on 45 preoperative variables to compare mortality and morbidity rates.

RESULTS

The unadjusted 30-day mortality was 2.0% for radical and 1.6% for partial nephrectomy (P = 0.58). Risk-adjusting the two groups did not result in a statistically significant difference in mortality. The 30-day overall morbidity rate was 15% for radical and 16.2% for partial nephrectomy (P = 0.52); risk-adjusted morbidity rates were not statistically different. There were no statistically significant differences in the rates of postoperative progressive renal failure, acute renal failure, urinary tract infection, prolonged ileus, transfusion requirement, deep wound infection, or extended length of stay.

CONCLUSIONS

Partial nephrectomy carried out in the VA program has low morbidity and mortality rates, comparable with the complication rates after radical nephrectomy.

Imaging renal masses

Imaging plays a crucial role in the detection, characterization, and post-operative follow-up of renal masses. With rapidly advancing technology, imaging techniques are continuously evolving. This review will discuss the current modalities and techniques available for renal imaging, and recent developments.

Wilms' tumor. Surgical considerations and controversies

Although the therapeutic objectives for Wilms' tumor are to maximize outcomes and minimize treatment morbidity, there are some controversial issues related to different therapeutic protocols. In this article, the authors address some of the issues such as the roles of tumor biopsy, preoperative chemotherapy, contralateral exploration, and partial nephrectomy.

Preoperative use of 3D volume rendering to demonstrate renal tumors and renal anatomy

With increased use of computed tomography (CT) and abdominal ultrasonography, the indications for nephron-sparing surgery are also increasing. Triphasic helical CT and three-dimensional (3D) volume rendering can be combined into a single noninvasive test to delineate renal tumors and normal and complex renal anatomy prior to nephron-sparing surgery. This combination technique has proved accurate and very useful for both preoperative and intraoperative planning by demonstrating renal position, tumor location and depth of tumor extension into the kidney, relationship of the tumor to the collecting system, and renal vascular anatomy. Knowledge of the position of the kidney relative to the lower rib cage, iliac crest, and spine helps in planning the initial surgical incision. By depicting tumor location and depth of extension, helical CT with 3D volume rendering helps ensure complete tumor excision and conservation of adjacent normal renal parenchyma. Depiction of the relationship of the tumor to the collecting system helps anticipate further tumor extension and minimize postoperative complications. Identification of normal renal vasculature and anatomic variants can help minimize ischemic injury and intraoperative bleeding. Radiologists should be familiar with current indications for nephron-sparing surgery and understand what information is required prior to surgery.

MR imaging of the kidneys after laparoscopic cryoablation

OBJECTIVE

We describe the MR imaging findings of patients who underwent laparoscopic renal lesion cryoablation.

MATERIALS AND METHODS

Twenty-one patients (men, 11; women, 10; age range, 36-84 years; average age, 65.5 years; SD, 11.9) with 23 small renal masses (< or =4 cm) underwent laparoscopic renal lesion cryoablation. Twenty patients (22 masses) underwent follow-up MR imaging on the first day after surgery, 12 (13 masses) at 1 month, 16 (18 masses) at 3 months, 14 (15 masses) at 6 months, and 12 (12 masses) at 12 months. Three radiologists retrospectively reviewed MR images for the signal intensity, characteristics, and size of cryolesions. CT-guided needle biopsy was performed 6 months after cryoablation (18 patients) and no evidence of malignancy was discovered.

RESULTS

Including all lesions at all times on T1-weighted images, cryolesion signal intensity was isointense to renal parenchyma (47/76, 61.8%) or isointense with hyper- or hypointense foci (7/76, 9.2%). On T2-weighted images, almost all lesions (72/76, 94.7%) were isointense or hypointense, and there was a hypointense rim between the cryolesion and renal parenchyma in 38.2% of lesions (29/76). A thin peripheral rim of enhancement was noted in 19.7% (14/74) of lesions. Cryolesions decreased in size an average of 61.5% (SD, 22.82; n = 12) at 1 month, 78.7% (SD, 13.5; n = 17) at 3 months, 83.5% (SD, 24.3; n = 15) at 6 months, and 94.2% (SD, 8.1; n = 11) at 1 year after cryoablation (one patient was not scanned 1 day after cryoablation and was not included in our calculations).

CONCLUSION

After renal cryoablation, MR imaging revealed common signal characteristics such as low-signal-intensity rims on T2-weighted images, enhancement patterns such as thin peripheral rims, and interval size changes.

Radiofrequency ablation of rabbit kidney using liquid electrode: acute and chronic observations

BACKGROUND AND PURPOSE

The percentage of small renal tumors being diagnosed has increased at least five-fold in the last 20 years. The question of how best to treat these lesions remains unanswered. We studied the effectiveness of "wet" radiofrequency (RF) ablation of renal tissue.

MATERIALS AND METHODS

New Zealand white rabbits (N = 48) underwent a 1- or 2-minute ablation of renal parenchyma with a modified insulated spinal needle capable of infusing saline, measuring temperature and impedance, and delivering RF energy. Animals were followed and examined up to 54 days after surgery.

RESULTS

All animals survived for the planned period. Intravenous urograms showed no fistula or urinoma formation and confirmed continued function of the remaining parenchyma. The 1-minute treatments consistently ablated 20% to 25% (average 7 cm) of the tissue, whereas the 2-minute treatments ablated 34% to 36% (average 10 cm). Acutely, there was coagulative necrosis and infiltration of inflammatory cells. Chronically, there were well-demarcated lesions with complete effacement of the tubular epithelium and destruction of the glomeruli.

CONCLUSION

Wet radiofrequency ablation with a liquid electrode can reproducibly create large lesions safely and quickly. The technique may soon become an alternative, minimally invasive therapy for small renal tumors.

Comparison of direct hospital costs and length of stay for radical nephrectomy versus nephron-sparing surgery in the management of localized renal cell carcinoma

OBJECTIVES

Recent work has demonstrated comparable surgical results and 5-year cancer-specific survival rates between radical nephrectomy and nephron-sparing surgery (NSS) in the treatment of patients with small (4 cm or smaller) solitary renal cell carcinomas (RCCs). However, differences exist in the intraoperative management and postoperative care of patients undergoing NSS versus radical nephrectomy, and we sought to compare direct hospital costs and length of stay (LOS) between these two groups to determine whether either treatment imparts a specific cost advantage.

METHODS

Data were retrieved from medical records and administrative data sets containing billing encounters for all costs incurred during hospitalization at the Cleveland Clinic Foundation. Individual costs were grouped together using nine cost center categories encompassing every aspect of direct hospital care, including anesthesiology, laboratory, radiology, nursing, pharmaceutical, and emergency services, and medical care, surgical care, and miscellaneous costs. Each cost center was further subdivided, and a total of 52 cost subcategories were assessed. The total direct costs of hospitalization were compared using a multivariate regression model in which patient demographics and tumor characteristics, type and year of surgery, LOS, and cost center categories were assessed as single and interactive factors. Postoperative complication and cancer-specific survival rates were also compared to identify any potential therapeutic differences between the two groups.

RESULTS

Between 1991 and 1995, 80 patients underwent surgery at the Cleveland Clinic Foundation for solitary RCCs 4 cm or smaller, including 52 partial and 28 radical nephrectomies. We found no difference in the postoperative complication rate or cancer-specific survival rate between the two surgical groups. Total direct hospital costs and LOS were not statistically different between the NSS and radical nephrectomy groups (P >0.05). This was further supported by our multivariate model, which accounted for 61% of the observed variance in the total costs (F = 12.11, P = 0.0001). The type of surgery was not associated with total cost when controlling for all other factors, including age, sex, year of surgery, tumor size, grade, and stage, and postoperative complications (P = 0.7). There was no significant interaction between the type of surgery and the LOS (P = 0.5).

CONCLUSIONS

This study demonstrated that elective NSS can be performed with equivalent direct hospital costs and LOS when compared with patients undergoing radical nephrectomy for small solitary RCCs. These data have significant economic implications for the comparison of competing surgical treatment strategies for localized RCC.

Adenocarcinoma of the kidney: nephron-sparing surgical approach vs. radical nephrectomy

BACKGROUND AND OBJECTIVES

Radical nephrectomy has been the traditional surgical treatment for renal cell carcinoma in patients with a normally functioning contralateral kidney. The necessity for a less aggressive surgical approach has emerged in cases in which there is a need to preserve renal function.

METHODS

We retrospectively evaluated the records of 41 patients with localized, symptomless small renal masses (<5 cm) treated with nephron-sparing surgery (group A) and 48 patients matched for age, tumor location, size, and stage who were treated with radical nephrectomy (group B).

RESULTS

The 5-year cancer-specific survival rates were 97.5% and 98. 4% for the treated patients of groups A an B, respectively. No statistical association was found between cancer-specific survival and surgical approach, tumor stage, tumor location, or recurrence. The size of the primary tumor did not seem to influence the cause-specific survival. Local recurrence was observed in 3 patients (7.3%) who underwent partial nephrectomy. In our series, the overall incidence of multifocality was 10.4%.

CONCLUSIONS

We propose segmental renal resection for unifocal small adenocarcinoma of the kidney in preference to radical surgery as it is corroborated by the presented data.

Efficacy of nephron-sparing surgery for renal cell carcinoma: analysis based on the new 1997 tumor-node-metastasis staging system

PURPOSE

To analyze the experience with nephron-sparing surgery as a treatment modality for renal cell carcinoma (RCC).

PATIENTS AND METHODS

Between 1980 and 1997, 146 patients underwent partial nephrectomy at the University of California-Los Angeles Medical Center. A matched group of 125 patients who underwent radical nephrectomy at the same institution between 1986 and 1997 were selected for comparison. Patients were monitored for an average period of 57 months. Patients were staged according to both the 1997 and 1987 tumor-node-metastasis (TNM) staging criteria. Survival data were calculated in terms of both staging criteria.

RESULTS

When comparing cancer-specific survival rates for patients with T1 lesions under both the 1987 and 1997 TNM staging criteria, no statistically significant difference in survival was noted (P =.53), although most of the tumors in our series measured < or = 4 cm. Patients with T2 lesions (1997 TNM) demonstrated a significant decrease in survival (66%) when compared with patients with T1 lesions (100%; P <.001). No statistically significant difference in survival for patients with T1 RCC treated with either radical or partial nephrectomy was noted (P =.219). Survival rates of partial and radical nephrectomies for patients with unilateral T1 RCC and a normal contralateral kidney also were not significantly different (P =.53). In contrast, for patients with lesions greater than T1, survival rates were significantly higher with radical versus partial nephrectomy (P =.001).

CONCLUSION

Partial nephrectomy has become an effective method of treating T1 RCC lesions as categorized by both the 1987 and the revised 1997 TNM staging criteria. Selected patients with localized unilateral RCC lesions less than 7 cm (ideally, < 4 cm) and a normal contralateral kidney will benefit from partial nephrectomy.