Nephron sparing surgery for renal cell carcinoma

Tracing the evolving dynamics and research hotspots in the kidney neoplasm and nephron sparing surgery field from the past to the new era

BACKGROUND

With increasing detection of small renal masses and accumulating evidence that nephron sparing surgery (NSS) could achieve oncological equivalence and functional superiority compared with radical nephrectomy (RN), NSS has become first-line therapy for some patients with localized renal masses.

OBJECTIVE

This study aims to review the publications in the kidney neoplasm and NSS field, exploring the research hotspots.

METHOD

Kidney neoplasm and NSS related publications before July 3th 2023 were obtained from the Web of Science Core Collection database. We then used bibliometric analysis to conduct performance analysis, citation analysis and co-citation network of publications, together with keyword co-occurrence analysis.

RESULTS

Seven thousand five hundred and sixty-four documents were finally retrieved, and the annual publications increased exponentially. The most productive authors were "KAOUK JH" and "GILL IS", while USA, and 12 American affiliations such as CLEVELAND CLINIC FOUNDATION and MAYO CLINIC were far leading in this field. Journal of Urology and European Urology were journals with the highest citations and h-index.

DISCUSSION

Through literature reviewing plus co-occurrence and clustering analysis, the therapeutic effects of partial nephrectomy (PN) versus RN on patients with localized renal cell carcinoma, different operative approaches of PN, and conservative NSS methods were deemed as the most focused topics.

CONCLUSION

Three aspects were the most important hotspots in this field. Firstly, how to provide the optimal management choices for different patients. Secondly, therapeutic effects of different management options and surgical techniques needed more prospective and randomized studies. Finally, more novel technologies and surgical techniques were required.

Does a Positive Surgical Margin After Nephron Sparing Surgery Affect Oncological Outcome in Renal Cell Carcinoma? A Systematic Review and Meta-analysis

We systematically evaluated the impact of positive surgical margins (PSM) on oncological outcomes after partial nephrectomy for renal cell carcinoma. Forty-two studies comprising 101,153 subjects were included and five distinct meta-analyses were performed. PSM was associated with increased risk of local recurrence (hazard ratio (HR) 6.11-high certainty), metastasis (HR 3.29-moderate certainty), overall relapse (HR 2.25-high certainty), overall mortality (HR 1.30-moderate certainty), and may be associated with increased cancer-specific mortality (HR 1.91-low certainty). Patients with PSM should be counseled for the possibility of additional surgery, novel adjuvant therapies, and more rigorous surveillance.

5-Item Modified Frailty Index as a Preoperative Predictor of Morbidity Following Minimally Invasive Partial Nephrectomy

OBJECTIVE

To apply the modified frailty index-5 (mFI-5) to those patients undergoing minimally invasive partial nephrectomy (MIPN) to examine the relationship between frailty and postoperative outcomes.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, data were retrospectively reviewed between 2012 and 2018 for cases coded for MIPN. The mFI-5 score was defined on a scale of 1 to 5, with each patient receiving one point per each of the following comorbidities: congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), diabetes mellitus, hypertension that requires medication and functional health status of partial or total dependence prior to surgery. Complications were examined within the first 30 days postoperatively. Using univariate and multivariate logistic regression, postoperative outcomes were obtained and stratified based on frailty score.

RESULTS

Of the 18,904 cases identified between 2012 and 2018, mFI-5 score was 0 for 38.0% of patients, 1 for 42.8%, ≥2 for 19.2%. With increasing mFI-5 score, a significant increase in multiple postoperative morbidities were identified (P <0.05). 11.2% of patients with mFI-5 ≥2 had complications vs 5.3% with mFI-5 of 0 and 7.8% mFI-5 of 1, P <0.05. Multivariate analysis revealed nearly 50% increase in the odds of having an overall complication for patients with mFI-5 score ≥2 (OR = 1.48, 95% CI 1.22 - 1.80, P <0.001).

CONCLUSION

The mFI-5 is a well defined and easily ascertainable predictor of postoperative outcomes in those undergoing MIPN and could be used preoperatively to identify and counsel those at increased risk for morbidity.

The impact of comorbidities, sex and age on the occurrence of acute kidney injury among patients undergoing nephron-sparing surgery

Background

The aim of this study was to report the impact of patients' baseline characteristics on the incidence of acute kidney injury (AKI) after nephron-sparing surgery (NSS) for localized kidney cancer.

Patients and methods

Data from our kidney cancer database were retrospectively extracted to include 402 patients who underwent NSS between March 2000 and June 2016, and had sufficient data. Definition of AKI was based on the postoperative serum creatinine levels and estimated glomerular filtration rate (eGFR) magnitude, which were measured during the 72 h after surgery.

Results

Based on RIFLE and AKIN criteria, the overall rate of postoperative AKI was 35%. The average decrease in eGFR among patients who developed AKI was 20% as compared with the non-AKI subgroup (2%). In univariate analysis, variables that were associated with AKI included right-sided tumors (p = 0.014), male sex (p = 0.01), hypertension (p = 0.003), baseline eGFR (p = 0.009) and history of nephrolithiasis (p = 0.039). However, multivariate analysis revealed that the only independent predictors of postoperative AKI were hypertension (p = 0.009) and cigarette smoking (p = 0.024).

Conclusion

AKI is a common complication of NSS affecting about one-third of the patients. The most important risk factors are hypertension and smoking.

Impact of Comorbidities on Functional Recovery from Partial Nephrectomy

PURPOSE

Parenchymal mass preservation, and ischemia type and/or duration can influence functional recovery after partial nephrectomy. Some groups have hypothesized that relevant comorbidities may also impact nephron stability and functional recovery but this has not been adequately investigated.

MATERIALS AND METHODS

At our center 405 patients treated with partial nephrectomy from 2007 to 2015 had the necessary data to determine the function and parenchymal mass preserved in the ipsilateral kidney. Comorbidities potentially associated with renal functional status were reviewed, including various degrees of hypertension, diabetes, cardiovascular disease, obesity, smoking status and related medications. Multivariable linear regression was done to assess factors associated with functional recovery, defined as the percent of preserved ipsilateral glomerular filtration rate.

RESULTS

Median tumor size was 3.5 cm and the median R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines and tumor touching main renal artery or vein) score was 8. Warm and cold ischemia were done in 264 (65%) and 141 patients for a median duration of 21 and 27 minutes, respectively. The median preserved ipsilateral glomerular filtration rate was 79%. Patient age, comorbidity index, hypertension and proteinuria were each associated with the preoperative glomerular filtration rate (all p <0.01). On univariable and multivariable analyses the preserved parenchymal mass, and ischemia type and duration were significantly associated with functional recovery (all p <0.001). On univariable analysis of comorbidities only hypertension was significantly associated with functional recovery. However, on multivariable analysis none of the analyzed comorbidities were associated with functional recovery.

CONCLUSIONS

Recovery of function after partial nephrectomy depends primarily on parenchymal mass preservation and ischemia characteristics. Comorbidities failed to be associated with functional outcomes. Comorbidities can impact function, leading to surgery, and may influence long-term functional stability. However, our data suggest that they do not influence short-term recovery after partial nephrectomy.

Radiotherapy for renal cell carcinoma: renaissance of an overlooked approach

Conventional radiotherapy previously had a limited role in the definitive treatment of renal cell carcinoma (RCC), owing to the disappointing outcomes of several trials and the perceived radioresistance of this type of cancer. In this context, radiotherapy has been relegated largely to the palliation of symptoms in patients with metastatic disease, with variable rates of response. Following the availability of newer technologies that enable safe delivery of high-dose radiotherapy, stereotactic ablative radiotherapy (SABR) has become increasingly used in patients with RCC. Preclinical evidence demonstrates that RCC cells are sensitive to ablative doses of radiotherapy (≥8-10 Gy). Trials in the setting of intracranial and extracranial oligometastases, as well as primary RCC, have demonstrated excellent tumour control using this approach. Additionally, an awareness of the capacity of high-dose radiation to stimulate antitumour immunity has resulted in novel combinations of SABR with immunotherapies. Here we describe the historical application of conventional radiotherapy, the current biological understanding of the effects of radiation, and the clinical evidence supporting the use of ablative radiotherapy in RCC. We also explore emerging opportunities to combine systemic targeted agents or immunotherapies with radiation. Radiotherapy, although once an overlooked approach, is moving towards the forefront of RCC treatment.

Current Status of Nephron-Sparing Surgery (NSS) in the Management of Renal Tumours

Nephron-sparing surgery has emerged as the surgical treatment of choice for small renal masses over the past two decades, replacing the traditional teaching of radical nephrectomy for renal cell carcinoma. With time, there has been an evolution in the techniques and indications for partial nephrectomy. This review summarizes the current status of nephron-sparing surgery for renal carcinoma and also deals with the future of this procedure.

Nephron-Sparing Surgery — Strategies for Partial Nephrectomy in Renal Cell Carcinoma

The use of partial nephrectomy for renal cell carcinoma has continuously changed in the clinical practice. Previously it was mostly used in imperative cases, in patients with a solitary kidney or in patients with a risk of renal failure. An increased number of incidentally detected renal cell carcinomas are diagnosed due to the advances of the radiological methods. These tumours tend to be smaller and generally with a lower stage. The reported excellent results of partial nephrectomy have promoted the use of nephron-sparing surgery also in patients with a normal contralateral kidney and tumours smaller than 4-5 cm. The technical outcome is excellent with a low operative morbidity and a good oncologic control. Therefore partial nephrectomy has become a standard technique in the treatment of properly selected patients. Laparoscopy with its reduced postoperative pain and shorter rehabilitation time, has encouraged the interest in minimally invasive nephron sparing surgical techniques. Although low, the risk of local tumour recurrence and surgical complications are higher after nephron-sparing surgery compared with radical nephrectomy. Furthermore, long-term renal function remains adequate in most patients with a normally functioning contralateral kidney also after radical nephrectomy. Albeit these facts, there is convincing evidence justifying nephron-sparing surgery to be used routinely for patients with a small renal cell carcinoma and a normal functioning contralateral kidney.

Emerging surgical treatments for renal cell carcinoma

Treatment of renal cell carcinoma has evolved considerably over the last few years. While total nephrectomy is necessary at times, nephron-sparing surgery, with a goal of renal function preservation, should always be considered. Although open partial nephrectomy is considered the gold standard approach for nephron-sparing surgery, laparoscopic- or robotic-assisted techniques allow urologists to perform renal surgery less invasively, with excellent long-term oncological outcomes. Cryotherapy and radiofrequency ablation are less invasive management approaches for carefully selected patients with small renal masses. Active surveillance should be considered in elderly or patients who are unfit for surgery. Ultimately, the method chosen for management of a renal mass is an informed decision made by the physician and patient.

Open partial nephrectomy: ancient art or currently available technique?

Renal cell carcinoma (RCC) accounts for 3 % of adult solid tumors, with the highest incidence between 50 and 70 years of age. Nephron-sparing surgery was initially reserved to patients with small renal masses detected in anatomically or functionally solitary kidney or in the presence of multiple bilateral tumors or hereditary forms of RCC, which posed a high risk of developing a tumor in the contralateral kidney. Nowadays, partial nephrectomy (PN) has grown up to an established approach for the treatment of small renal masses. In patients with T1a-staged RCCs, PN has proven to be associated with better survival, long-term renal function preservation with lower dialysis need or renal transplantation. Currently, most of the kidney masses are incidentally detected, up to 40 %, with smaller size due to the widespread use of imaging modalities such as ultrasound, computed tomography and magnetic resonance. Here we review the role of open PN in the management of small renal masses particularly focusing on indications, oncological outcomes and comparison with laparoscopic and robotic PN. Recent studies demonstrate that PN confers better survival, oncologic equivalence and lower risk of severe chronic kidney disease compared to radical nephrectomy becoming then the gold-standard surgical technique, even if increasingly challenged by laparoscopic and/or robot-assisted partial nephrectomy which in the hands of experts seems to achieve comparable outcome results albeit with slightly higher complication rate.

Renal cell carcinoma: risks and benefits of nephron-sparing surgery for T1 tumors

Renal cell carcinoma is the most common cancer of the kidneys that is primarily treated with surgery, including removal of part or all the involved kidney depending on size and tumor, complexity, and patient characteristics. Partial nephrectomy historically was restricted to cases of solitary kidney or bilateral tumors. It was then started for masses smaller than 4 cm and currently is even studied and justified in tumors smaller than 7 cm if surgically feasible. Although partial nephrectomy preserves kidney tissue and, therefore, delays or prevents the new onset of CKD and ESRD, radical nephrectomy is still overused even for the small tumors. Studies have shown that although this practice is driven by an easier complete removal of the kidney especially in the era of minimally invasive surgery, partial nephrectomy is successful in curing cancer and achieving excellent cancer-specific survival in addition to its benefits on cardiovascular health. Nowadays interest in preserving healthy kidney tissue is increasing to the level of studying the impact of larger volume removed around the kidney and the histopathology of that non-neoplastic tissue to predict kidney function behavior postoperatively.

Open mini-flank partial nephrectomy: an essential contemporary operation

Secondary to the widespread use of the modern imaging techniques of computed tomography, magnetic resonance imaging, and ultrasound, 70% of renal tumors today are detected incidentally with a median tumor size of less than 4 cm. Twenty years ago, all renal tumors, regardless of size were treated with radical nephrectomy (RN). Elective partial nephrectomy (PN) has emerged as the treatment of choice for small renal tumors. The basis of this paradigm shift is three major factors: (1) cancer specific survival is equivalent for T1 tumors (7 cm or less) whether treated by PN or RN; (2) approximately 45% of renal tumors have indolent or benign pathology; and (3) PN prevents or delays the onset of chronic kidney disease, a condition associated with increased cardiovascular morbidity and mortality. Although PN can be technically demanding and associated with potential complications of bleeding, infection, and urinary fistula, the patient derived benefits of this operation far outweigh the risks. We have developed a "mini-flank" open surgical approach that is highly effective and, coupled with rapid recovery postoperative care pathways associated with a 2-day length of hospital stay.

Current management considerations for the incidentally detected small renal mass

BACKGROUND

Nephron-sparing treatments remain underutilized for the management of small renal masses despite a rise in incidentally detected renal cell carcinoma and a downward stage migration.

METHODS

Historical publications representative of currently accepted paradigms were reviewed, and the results of a contemporary scientific literature search conducted in PubMed focusing on studies involving humans, published in English, and inclusive of clinical trials, meta-analyses, randomized controlled trials, and practice guidelines are included. Results from contemporary retrospective trials augment the data when level I or II evidence is absent.

RESULTS

Phase III clinical trial results substantiate the long-held tenet that partial nephrectomy is equivalent to radical nephrectomy with respect to safety and oncologic efficacy. Further, minimally invasive techniques using laparoscopy and robotic assistance to achieve partial nephrectomy appear equally effective to traditional open techniques. Although no prospective randomized studies are available, large retrospective studies support the notion that active surveillance and thermal ablative techniques are viable options for carefully selected patients.

CONCLUSIONS

The management of small renal masses encompasses a host of therapeutic options, all of which must be considered and discussed with the individual patient.

Retroperitoneal hand-assisted laparoscopic nephrectomy and partial nephrectomy

The purpose of the present paper is to describe our technique and experience with retroperitoneal hand-assisted laparoscopic (HAL) nephrectomies as an alternative to the transperitoneal approach. Eight retroperitoneal HAL nephrectomies and one partial nephrectomy were performed. Several excisional techniques were employed incorporating the Harmonic scalpel or Ligasure device. Hemostatic agents were used to cover the renal defect. Surgical bolsters were sutured to the renal capsule with pleget reinforcements to aid in hemostasis. The average operative time was 210 min and estimated blood loss 110 mL. Mean change in hematocrit was 3 units and creatinine was 1 point. No patient required a transfusion. There were no major complications, with a mean follow-up of fourteen months. On average, patients resumed oral intake in 2 days, and were discharged in 3 days. Pathological examination revealed that two lesions were benign and seven malignant. Tumor diameter averaged 3 cm. There were no positive surgical margins. In conclusion, we have demonstrated the feasibility of retroperitoneal laparoscopic hand-assisted nephrectomy and partial nephrectomy surgery for solid renal masses.

Kidney function following partial or radical nephrectomy for renal cell carcinoma: a population-based study

OBJECTIVE

The aim of this retrospective study was to compare kidney function in a population-based cohort of renal cell carcinoma (RCC) patients after partial (PN) or radical nephrectomy (RN).

MATERIAL AND METHODS

Forty-four consecutive RCC patients who had undergone PN in Iceland between 2000 and 2010 were compared with 44 controls matched for tumour, node, metastasis (TNM) stage who had undergone RN during the same period. Estimated glomerular filtration rate (eGFR) and survival were calculated, and predictors of chronic kidney disease (CKD) were evaluated with multivariate analysis.

RESULTS

In 16 cases (36%), PN was performed for imperative reasons (single kidney, decreased kidney function or bilateral kidney tumours) but 28 patients had a normal contralateral kidney. The groups were similar regarding preoperative eGFR, median follow-up and TNM stage, but age and American Society of Anesthesiologists (ASA) score were significantly higher in the RN group. Six months after surgery, eGFR was significantly higher in the PN group. By multivariate analysis, RN contributed negatively to eGFR 6 months after surgery (-12.6 ml/1.73 m², p < 0.001) and increased the risk of new-onset CKD (odds ratio = 3.07, 95% confidence interval 1.03-9.79, p = 0.04), compared to PN. At median follow-up of 44 months, no patients in either group had a recurrence of RCC. The 5-year overall survival (Kaplan-Meier) was 100% and 65% in the PN and RN groups, respectively (log-rank test, p < 0.001).

CONCLUSION

eGFR was significantly lower after RN, and these patients were three times more likely to develop new-onset CKD. These findings suggest that PN successfully preserves kidney function compared to RN, with good oncological outcome and survival.

Oncological and renal medical importance of kidney-sparing surgery

In the past decade, the medical and oncological rationale for kidney-sparing surgical approaches for small renal masses has been clarified. Although radical nephrectomy is still necessary for many patients diagnosed with large renal tumours, accumulating evidence indicates that partial nephrectomy provides equivalent oncological outcomes while also preserving renal function and preventing the adverse cardiovascular effects of chronic kidney disease. Furthermore, approximately 45% of resected small renal tumours are benign or indolent, with limited--if any--metastatic potential. Patients who develop kidney cancer often have medical comorbidities that can affect kidney function, such as diabetes and hypertension, and histological examination of the non-tumour-bearing elements of the kidney demonstrate significant pathological changes in the vast majority of patients. For elderly patients or patients with comorbidities, active surveillance provides an alternative kidney-sparing approach, and is associated with extremely low rates of clinical disease progression and metastases. Despite these important advances in understanding, which support the use of partial nephrectomy for the treatment of small renal masses, the technique remains underused.

Renal cell carcinoma : clinical features and management

In 1999 it was estimated that renal cell carcinoma (RCC) would account for 29,990 new cancer cases diagnosed in the United States (61% in men and 39% in women), and lead to 11,600 deaths. RCC accounts for 2-3% of all malignancies in adults and causes 2.3% of all cancer deaths in the United States annually (1). Approx 4% of all RCC cases are bilateral at some point in the life of the patient. Data from over 10,000 cases of renal cancer entered in the Connecticut Tumor Registry suggests an increase in the incidence of renal cancer from 1935-1989; in women the incidence increased from 0.7 to 4.2 in 100,000, and in men from 1.6 to 9.6 in 100,000 (2). Factors implicated in the development of RCC include cigarette smoking, exposure to petroleum products, obesity, diuretic use, cadmium exposure, and ionizing radiation (3-9).

Probe ablation as salvage therapy for renal tumors in von Hippel-Lindau patients: the Cleveland Clinic experience with 3 years follow-up

BACKGROUND

To evaluate the efficacy and safety of probe ablative therapy as salvage treatment for renal tumor in von Hippel-Lindau (VHL) patients after previous partial nephrectomy (PN).

METHODS

Medical records of VHL patients undergoing probe ablative treatment for renal tumors from March 2003 to January 2010 at our institution were retrospectively analyzed.

RESULTS

Fourteen VHL patients who were submitted to salvage probe ablative therapy were included in the analysis. Twelve patients (85%) had a solitary kidney. Overall, 33 tumors were ablated by either percutaneous cryoablation (P-Cryo) (n of procedures = 13), radiofrequency ablation (RFA) (n = 14), and laparoscopic cryoablation (L-Cryo) (n = 3). Average maximal renal tumor diameter was 2.6 ± 1 cm. Average ablation time was 18.3 ± 2.1 minutes for P-Cryo, 36.7 ± 17 minutes for RFA, and 17.3 ± 4 minutes for L-Cryo. All procedures were successfully completed without transfusions and intraoperative complications. No early postoperative complications were recorded. Postoperative decline in renal function was minimal and not clinically significant. With a mean follow-up of 37.6 months (range 12-82), 4 patients had a suspicious recurrence on computed tomography/magnetic resonance imaging (CT/MRI) scan and in 3 of them a re-ablation was performed. Actuarial overall and cancer-specific survivals were 92% and 100%, respectively.

CONCLUSIONS

Probe ablative therapy seems to represent a suitable treatment option for VHL patients with a previous history of PN as it offers a repeatable operation, with a high technical success rate and causing minor changes in renal function.

[Partial nephrectomy for cancer and percutaneous biopsy: Oncologic results]

OBJECTIVES

To evaluate the results of partial nephrectomy (NP) for cancer in 60 patients selected by the biopsy of the tumor by analyzing the information, oncologic follow-up.

PATIENTS

It was a cohort study unicenter retrospective from 1994 to 2006. The biopsy was systematically done for patients who were candidates for elective NP. The criteria for elective indications NP tumors were less than 4cm, low grade Fuhrman (I and II). The tubulopapillary tumors (TBP) on biopsy were excluded from the elective indications. The parameters studied were the biopsy data, overall survival, disease-free survival.

RESULTS

The median age was 59 years (32-79 years) and 69% of tumor were fortuitous discovery. Indications of need accounted for 30% of cases (single kidney, bilateral tumors and chronic renal failure [CRF]). Biopsy allowed a diagnosis in 89% of cases. There was one death in specific postoperative immediately. A final histology was 75% of clear cell carcinoma, 13.3% of chromophobe and 11.7% of TBP, 96.6% of T1a including 86.6% of low grade and no surgical margin. The median follow-up was 49 months with 98.5% of specific survival at 5 years, one local recurrence and no general recurrence.

CONCLUSION

The study has shown that the selection of patients by biopsy gives satisfactory carcinologic results with 98.5% specific survival at the end of follow-up; it is between 89 and 100% in the literature.

Conservative treatment of persistent calyceal fistula after tumor excision. Case report and clinical remarks

Background

Nowadays, ultrasounds allow to discover accidentally a large number of renal small tumors. So, radical nephrectomy, which years ago was considered as the gold standard, is rarely required. Today, nephron sparing surgery is often prescribed for renal masses smaller than 4 cm. Its most frequent complication is calyceal fistula. It can be prevented exploring carefully the surgical surface, and suturing any opening. It can heal over within a few days or some weeks, so it can be a trouble for both the patient and the surgeon. A complete urinary drainage, obtained with an ureteral stent and an open bladder catheter, helps heal. Recently, it has become common practice to spread synthetic or biological tissue sealants over the surgical surface, to improve hemostasis. These surgical glues have also been used to repair calyceal openings, with conflicting results.

Methods

We performed left renal tumor excision (3.5 × 3 cm) in a 72-years-old man, during temporary renal artery occlusion with surface hypothermia. We placed intraoperatively an ureteral stent. The visual examination of the surgical cavity did not reveal any calyceal opening. We electrocauterized it and stuffed it with FloSeal. Surgical edges were free from illness. After 5 days urinary leakage from the drainage tube increased. Pyelography showed a calyceal fistula. A further stent was placed, with no results. Bladder catheter was kept open for about 2 months. Urinary leakage stopped 34 days after surgery.

Results

Urinary leakage increased when the catheter was removed, and stopped only after many days of complete urinary drainage.

Conclusions

The conservative treatment of a calyceal fistula must be considered a still effective therapy, also in difficult cases, provided that a complete and long-lasting urinary drainage is carried out.

Efficacy of parenchymal compression in open partial nephrectomies: a comparison with conventional vascular clamping

Purpose

We evaluated the efficacy of parenchymal compression in open partial nephrectomies (OPNs) compared with that of the conventional vascular clamping method.

Materials and Methods

OPNs were conducted by means of the parenchymal compression technique at our institution from April 2006. Among these, the operative outcomes of 20 consecutive patients with normal preoperative renal function (Group 1) were matched with those of 20 control patients from the database of previous operations who underwent OPN with a conventional vascular clamping method (Group 2).

Results

All preoperative characteristics were similar in both groups. The operative time was significantly higher for Group 2 (132.4±17.7 vs. 151.4±21.4 minutes, p=0.031). Estimated blood loss was slightly higher for Group 2, with marginal statistical significance (173.7±11.5 vs. 211.2±43.8 ml, p=0.06). Histologic examination revealed that over 80% of the tumors in both groups were renal cell carcinomas. For all patients, the pathology results of specimens were negative. Serum creatinine, checked at 1, 3, and 7 days after the operation, was significantly increased in both groups to a similar degree. However, 30 days after surgery, the patterns of serial serum creatinine levels demonstrated statistically significant differences by repeated-measures ANOVA (p<0.001), with a trend of more elevated in Group 2 than in Group 1, although values were within the normal range. No major complications occurred in either group.

Conclusions

OPN using the parenchymal compression method had acceptable outcomes in terms of complete tumor control, avoiding warm ischemic time, and minimizing blooding, with good preservation of renal function and minimal complications.

Prospective randomized trial comparing high lumbotomic with laparotomic access in renal cell carcinoma surgery

OBJECTIVE

We compared laparotomic with lumbotomic access in renal cell carcinoma (RCC) surgery by means of a prospective randomized trial, in order to evaluate differences in surgical time, blood loss, number of lymph nodes removed, duration of postoperative ileus and hospitalization, perioperative complications and progression-free and cancer-specific survival rates.

MATERIAL AND METHODS

Between November 1991 and November 1996, 94 patients with RCC were recruited and randomly assigned to undergo surgery by lumbotomic (n = 50) or laparotomic (n = 44) access. All patients underwent radical nephrectomy and lymph node dissection.

RESULTS

The mean surgical time was 59.1 min (range 20-140 min) and 84.4 min (range 40-180 min) for lumbotomic and laparotomic access, respectively (p < 0.01). Blood loss was 502 ml (range 200-1800 ml) for lumbotomic and 648 ml (range 200-2000 ml) for laparotomic access (p < 0.005). Mean hospital stay was 6.8 days (range 3-13 days) for lumbotomic and 8.2 days (range 5-15 days) for laparotomic access (p < 0.001). The perioperative complication rates were 6.1% and 13.6% for lumbotomic and laparotomic access, respectively. After a mean follow-up period of 7.5 years, cancer-specific and progression-free survival rates were 88% and 75%, respectively for lumbotomic and 88% and 72.7%, respectively for laparotomic access (p = NS). Multivariate analysis of risk factors showed that pathological stage was the best prognostic indicator of tumor progression, while other variables (age, tumor grade, surgical access, tumor size and incidental diagnosis of tumor) were not predictive of the prognosis of patients with RCC.

CONCLUSIONS

During radical nephrectomy, control of the renal vessels is easier and faster with high lumbotomic access. The suggested risk of tumor cell spread due to manipulation of the kidney before vessel ligature was not confirmed in our study. Because of the shorter surgical time, lower blood loss, lower perioperative and late complication rates and shorter hospital stay involved, lumbotomic access should be preferred to laparotomic access in radical nephrectomy for RCC.

[Does tumour diameter still limit the indications for partial nephrectomy in 2008?]

The indications for partial or radical nephrectomy of a kidney tumour are based on tumour diameter with a cut-off of 4cm. Tumour diameter has been demonstrated to be a continuous prognostic parameter which, ideally, should be integrated into multivariate prognostic models. The 4cm cut-off is reasonable, but was established pragmatically on the basis of series comprising selection biases. At least six series now question the validity of this cut-off, and some of them have demonstrated that partial nephrectomy and radical nephrectomy are equivalent in terms of cancer control for pT1b tumours. Furthermore, the excess mortality induced by broader indications for partial nephrectomy appears to be acceptable. These data appear to suggest that the feasibility of partial nephrectomy should be considered regardless of tumour diameter before proposing the indication for radical nephrectomy.

Ultrasound guided percutaneous microwave ablation for small renal cancer: initial experience

PURPOSE

We evaluated the feasibility, safety and efficacy of ultrasound guided percutaneous microwave ablation for small renal cell cancers.

MATERIALS AND METHODS

A total of 12 patients with a pathologically proven renal cell cancer 1.3 to 3.8 cm in diameter were treated with microwave ablation. A cooled shaft needle antenna was percutaneously inserted into the tumor under ultrasound guidance. One antenna was used for tumors 2 cm or smaller and antennae were used for tumors larger than 2 cm. One thermocouple was placed about 0.5 cm away from the tumor to monitor temperature in real time during ablation. Microwaves were emitted at 50 W for 500 seconds and prolonged as necessary to attain temperatures sufficient to ensure tumor kill. Immediate treatment efficacy was assessed by contrast enhanced ultrasound 1 day after ablation. Short-term efficacy was assessed by contrast enhanced computerized tomography and/or contrast enhanced ultrasound at 1, 3 and 6 months, and every 6 months thereafter.

RESULTS

All tumors were completely ablated at a single session and no complications occurred. No residual tumor or recurrence was observed at a median followup of 11 months (range 4 to 20). The ablation zone was well defined on contrast enhanced imaging and it gradually shrank with time.

CONCLUSIONS

Ultrasound guided percutaneous microwave ablation appears to be a safe and effective technique for small renal cell cancer in select patients.

Watchful waiting for small renal masses

Small renal masses (SRMs; < 4 cm in diameter) account for most renal tumors treated today. Incidental early detection of SRMs by abdominal imaging results in favorable grade and stage migration to renal cell carcinoma, and also increases detection of benign renal tumors. As a result, most SRMs manifest indolent biological behavior with excellent prognosis. Despite the increased use of minimally invasive laparoscopic surgery, nephron-sparing techniques, and percutaneous ablation therapy, selected patients are managed by initial active surveillance, reserving therapy for progression. Older patients and those with competing risks due to medical comorbidities are excellent candidates for active surveillance; their risk of early progression due to growth or metastases appears to be low. Active surveillance should not be recommended for younger, healthier patients until prognostic factors are better defined. Needle core use for improved histopathologic characterization of SRMs should be considered before recommending treatment.

Renal and cardiovascular morbidity after partial or radical nephrectomy

BACKGROUND

To clarify the benefits of nephron-sparing surgery among patients with early-stage kidney cancer, the authors compared the frequency of renal and cardiovascular morbidity after partial or radical nephrectomy.

METHODS

This retrospective cohort study was based on linked Surveillance, Epidemiology, and End Results-Medicare data. The authors identified 10,886 patients who underwent partial or radical nephrectomy between 1991 and 2002. Medical claims were examined for the occurrence of adverse renal and/or cardiovascular outcomes, and multivariate survival models were fit to estimate the association between type of surgery and each clinical outcome, using propensity scores to balance the treatment cohorts with respect to measured patient and disease characteristics. To control for secular trends in the indications for partial nephrectomy, separate analyses were performed based on treatment era (1991-1999 or 2000-2002).

RESULTS

During the study interval, 10,123 patients (93%) and 763 patients (7%) underwent radical or partial nephrectomy, respectively. During 2000 to 2002, patients who underwent partial nephrectomy experienced fewer adverse renal outcomes (16.4% vs 21.8%; adjusted hazard ratio, 0.74; 95% confidence interval, 0.58-0.94), including a trend toward less frequent receipt of dialysis services, dialysis access surgery, or renal transplantation. The likelihood of adverse cardiovascular outcomes did not differ by treatment.

CONCLUSIONS

Among contemporary patients, partial nephrectomy was associated with less clinically apparent renal morbidity than radical nephrectomy. This finding motivates expanded use of partial nephrectomy among patients with early-stage kidney cancer. Given the potential for selection bias and residual confounding in this observational cohort, additional prospective studies will be necessary to validate the current findings.

Impact of microwave tissue coagulation during laparoscopic partial nephrectomy on postoperative renal function

Laparoscopic partial nephrectomy for small renal tumors has been performed with increasing frequency over the past few years. We prospectively evaluated preoperative and postoperative differential renal function in patients with functioning contralateral kidneys who underwent laparoscopic partial nephrectomy using a microwave tissue coagulator without hilar clamping. Seven patients (five men and two women) in this prospective protocol underwent laparoscopic partial nephrectomy for exophytic tumors using a microwave tissue coagulator when the tumor was 2 cm or less in diameter. Renal scanning with 99technetium-labeled diethylenetetraminepentaacetic-acid scan was performed preoperatively and postoperatively at 7 days and 6 months after surgery in all patients. The mean tumor size and surgical duration were 17.0 +/- 2.3 mm and 161.1 +/- 20.5 min, respectively. Intraoperative blood loss was 35.6 +/- 40.7 ml. The preoperative glomerular filtration rate (GFR) and differential split renal function (SF) in the affected kidney were 45.7 +/- 12.8 ml/min and 50.5 +/- 3.3%, respectively. On postoperative day 7 and at 6 months, GFR and SF in the affected kidney were 36.2 +/- 9.0 and 36.8 +/- 10.9 ml/min and 44.3 +/- 4.1 and 45.0 +/- 5.1%, respectively. No postoperative complications occurred. Laparoscopic nonischemic partial nephrectomy using a microwave tissue coagulator has the advantage of technical ease and adequate hemostasis. However, its indication should be restricted to small exophytic renal tumors due to the expected collateral damage causing renal impairment.

[Partial nephrectomy for renal cancers larger than 4 cm]

OBJECTIVE

To compare the results in patients operated by partial nephrectomy (PN) and radical nephrectomy (RN) for renal cancers < 4 cm, between 4 and 7 cm and > 7 cm.

MATERIALS AND METHODS

Retrospective study including 107 patients operated for renal cancer between 1998 and 2004. Demographic characteristics, TNM stage, tumour diameter and type of surgery (PN vs RN) were recorded. The patients' current status was determined and a survival curve was constructed by the Kaplan-Meier method.

RESULTS

35.2% patients were operated by PN and 64.8% were operated by RN. The mean follow-up was 45 months. No significant difference in recurrence-free survival rate was observed between patients operated by PN and RN for tumours < 4 cm (93.3% vs 92.3%, respectively, p = 0.243), or for tumours between 4 and 7 cm (100% vs 89.3%, respectively, p = 0.564) or for tumours > 7 cm (100% vs 85.5%, respectively, p = 0.218).

CONCLUSION

Partial nephrectomy is the standard treatment for tumours < 4 cm, but this study suggests that it is just as effective for tumours up to 7 cm in diameter. Although partial nephrectomy also appears to be a safe treatment for tumours > 7 cm, further studies based on a greater number of tumours in this size category with a longer follow-up are necessary.

[Laparoscopic approach in partial nephrectomy]

Except for segmental parenchymal atrophies, partial nephrectomy is more and more often indicated when treating isolated small renal tumours. During the last few years this technique has been increasingly accepted for the excision of tumours less than 4 centimetres. In order to diminish the operative morbidity, the laparoscopic approach has been proposed. During the last decade, laparoscopic partial nephrectomy "has come to maturity" and this technique is now well standardized. Knowledge and operative skills are required for both trans-peritoneal and extra-peritoneal route. Extra-peritoneal approach is more suitable for posterior lesions or at the level of the lower pole while the trans-peritoneal route is preferred in case of tumours near the renal hilum or on the anterior surface. Different methods offering temporary arrest of renal perfusion have been elaborated. There is a clear tendency for renal parenchyma sectioning without the use of any kind of thermal energy. This allows a better identification of renal lesions. Sectioned collecting system, blood vessels and renal parenchyma are systematically sutured. Despite its complexity, this technique has become reproducible and reliable in specialized laparoscopic centres.

Percutaneous cryoablation of renal cell carcinoma guided by horizontal open magnetic resonance imaging

BACKGROUND

Cryoablation is a treatment option for some patients with small exophytic lesions of the kidney. The purpose of this study is to determine the feasibility, safety, and intermediate-term treatment outcome of percutaneous cryoablation of renal cell carcinoma guided by horizontal open magnetic resonance imaging (MRI).

METHODS

We prospectively used cryoablation to treat 13 patients with radiographically confirmed enhancing small, solid renal tumors (< or =4.8 cm). An argon gas-based cryoablation system was used. One to four cryoprobes with 2 or 3-mm diameters were placed percutaneously into the tumor under local anaesthesia and MRI guidance. Ice ball dimensions were monitored by 2-D MR images. Double freeze-thaw cycles were conducted throughout the procedure. After successful cryoablation, patients were followed on a regular basis to evaluate the treatment's clinical outcome.

RESULTS

Median follow up from time of procedure is 35 months (range, 28-42). In all cases the entire procedure was accomplished without significant morbidity or complications. A mild retroperitoneal hematoma, which subsided spontaneously, was noted in one patient. Follow-up dynamic computed tomography (CT) at 3 months after operation confirmed the absence of enhancement in resolved tumor masses for 11 of 13 cases. None of these 11 patients had clinical evidence of recurrent disease at last follow up. The remaining two patients had lesions with some enhanced areas. Subsequent partial nephrectomy histologically confirmed the presence of vital tumor in, respectively, the center and the periphery of the residual masses. One of these patients developed multiple lung and ipsilateral adrenal metastases 13 months after surgical resection.

CONCLUSIONS

Percutaneous cryoablation of small renal cell carcinomas under horizontal open MRI guidance appears to be safe and feasible. An intermediate-term follow up continues to demonstrate efficacy in most patients; however, a few patients experience incomplete ablation with risk of treatment failure. The ideal candidates for this procedure still need to be determined in longer follow up with diligent observation.

[Solid renal mass up to 4 cm. Analysis of the diagnostic procedures, TNM staging and surgical treatment]

OBJECTIVES

We perform a retrospective review of renal tumors operated with a maximum size of 4 cm to determine if the diagnostic methodology was adequate, the TMN staging prognostic accuracy (UICC 2002) and the goal surgical treatment.

MATERIAL AND METHOD

Between 1984 to 2005, 78 renal units form 74 patients (4 bilateral synchronous) operated at the Service of Urology of the Hospital Alemán de Buenos Aires. Age distribution, sex, presentation form (incidental and symptomatic), diagnostic methodology, laboratory variables, surgical treatment (partial or radical surgery), histopathology, Fuhrman grade, tumor size, bilaterality, multicentricity, TNM staging, evolution and survival (Kaplan Meier) were analyzed.

RESULTS

78 renal units from a total of 192, 40.62% were analyzed. The median age was 58.72 years. 69% were male and 31% female. The presentation form was 91.90 % incidental and symptomatic 8.10% (Hematuria in 5 and lung metastasis in 1). The diagnosis was performing with ultrasound and CT scan 63 cases, in 4 was also used resonance magnetic imaging (RMI) and in 7 ultrasound and RMI. Arteriography was used in 11 cases, 3 showed tumor and 8 were normal. Biopsy was performing in 5 cases, all positive for clear cells carcinoma. Globular sedimentation was the only one laboratory abnormality in 12 cases. Surgical treatment was radical surgery in 35 renal units (44.87%) and conservative surgery in 43 units (55.13%). Pathology clear cells carcinoma (CCC) 79.48%, papillary carcinoma 1.28%, angiomyolipoma (AML) 8.97%, oncocytoma 7.69% and adenoma 2.56%. The Fuhrman grade was 1 in 76.19%; 2 in 20.63% and 3 in 3.18%. Bilateral tumor were found in 4 cases 2 CCC, 1 CCC and AML and 1 CCC and adenoma. Tumor median size was 2.93 cm. Staging was T1a 96.82%, T3a 1.59% and T3aM+ 1.59%. Follow-up could be made in 54 of 61 cases. At median follow-up of 52.25 months, 50 cases were disease free, 3 died by progression at 18, 33 and 82 months and all of them were symptomatic tumors, 1 died by a non related cause. Survival rate was 94%.

CONCLUSIONS

1)Ultrasound and CT scan obtained a highest diagnostic accuracy for solid renal mass. Biopsy in selective cases could contribute to achieve a correct treatment strategy. 2) Conservative surgery was the goal treatment in selected tumors up to 4 cm. and we believe that TNM staging should contemplate the presentation form to improve the prognostic value.

The Role of Imaging in the Surveillance of Urologic Malignancies

Urologic malignancies are common, accounting for approximately 25% of all new cancer cases in the United States. Patients with urologic malignancies require long-term surveillance to detect progression or recurrence as early as possible. The urologist is faced with the task of balancing patient safety and cost-effectiveness, while finding the most practical follow-up regimen. For each urologic malignancy, this article reviews the commonly used radiologic techniques for surveillance and offers recommended follow-up schedules.

Percutaneous radiofrequency ablation of renal tumors: Midterm results in 16 patients

PURPOSE

To evaluate the outcome of 16 patients after percutaneous radiofrequency ablation of renal tumors.

MATERIALS AND METHODS

Sixteen patients (nine women, seven men; mean age, 61+/-9 years) with 24 unresectable renal tumors (mean volume, 4.3+/-4.3 cm3) underwent CT-guided (n=20) or MR imaging-guided (n=4) percutaneous radiofrequency ablation using an expandable electrode (Starburst XL, RITA Medical Systems, Mountain View, CA) with a 150-W generator. The initial follow-up imaging was performed within 1-30 days after RF ablation, then at 3-6 month intervals using either CT or MRI. Residual tumor volume and coagulation necrosis was assessed, and statistical correlation tests were obtained to determine the strength of the relationship between necrosis volume and number of ablations.

RESULTS

Overall, 97 overlapping RF ablations were performed (mean, 3.5+/-1.5 ablations per tumor) during 24 sessions. Five or more RF ablations per tumor created significant larger necrosis volumes than 1-2 (p=.034) or 3-4 ablations (p=.020). A complete ablation was achieved in 20/24 tumors (primary technical success, 83%; mean volume of coagulation necrosis: 10.2+/-7.2 cm3). Three of four residual tumors were retreated and showed complete necrosis thereafter. Three major complications (one percuatneous urinary fistula and two ureteral strictures) were observed after RF ablation. No further clinically relevant complications were observed and renal function remained stable. During a mean follow-up of 11.2 months (range, 0.2-31.5), 15/16 patients (94%) were alive. Only one patient had evidence of local recurrent tumor.

CONCLUSION

The midterm results of percutaneous RF ablation for renal tumors are promising and show that RF ablation is well-suited to preserve renal function.