Robotic Versus Laparoscopic Partial Nephrectomy: A Systematic Review and Meta-Analysis

Context

Centres worldwide have been performing partial nephrectomies laparoscopically for greater than a decade. With the increasing use of robotics, many centres have reported their early experiences using it for nephron-sparing surgery.

Objective

To review published literature comparing robotic partial nephrectomy (RPN) with laparoscopic partial nephrectomy (LPN).

Evidence acquisition

An online systematic review of the literature according to Cochrane guidelines was conducted from 2000 to 2012 including studies comparing RPN and LPN. All studies comparing RPN with LPN were included. The outcome measures were the patient demographics, tumour size, operating time, warm ischaemic time, blood loss, transfusion rates, length of hospital stay, conversion rates, and complications. A meta-analysis of the results was conducted. For continuous data, a Mantel-Haenszel chi-square test was used; for dichotomous data, an inverse variance was used. Each was expressed as a risk ratio with a 95% confidence interval p < 0.05 considered significant.

Evidence synthesis

A total of 717 patients were included, 313 patients in the robotic group and 404 patients in the laparoscopic group (seven studies). There was no significant difference between the two groups in any of the demographic parameters except for age (age: p = 0.006; sex: p = 0.54; laterality: p = 0.05; tumour size: p = 0.62, tumour location: p = 57; or confirmed malignant final pathology: p = 0.79). There was no difference between the two groups regarding operative times (p = 0.58), estimated blood loss (p = 0.76), or conversion rates (p = 0.84). The RPN group had significantly less warm ischaemic time than the LPN group (p = 0.0008). There was no difference regarding postoperative length of hospital stay (p = 0.37), complications (p = 0.86), or positive margins (p = 0.93).

Conclusions

In early experience, RPN appears to be a feasible and safe alternative to its laparoscopic counterpart with decreased warm ischaemia times noted.     

Partial Nephrectomy Is Associated with Improved Overall Survival Compared to Radical Nephrectomy in Patients with Unanticipated Benign Renal Tumours

Background

Partial nephrectomy (PN) has been associated with improved overall survival (OS) in select cohorts with localised renal masses when compared to radical nephrectomy (RN). The driving forces behind these differences have been difficult to elucidate given the heterogeneity of previously compared cohorts.

Objective

Compare OS in a subset of patients with unanticipated benign renal masses to minimise the confounding effect of cancer.

Design, setting, and participants

We retrospectively evaluated 2608 consecutive clinical T1 enhancing renal masses that were treated with extirpative surgery at our institution between 1999 and 2006. Of these, 499 tumours (19%) were found to be benign on final pathology. Preoperative data and renal functional data were used to generate a propensity model that was then plugged into a multivariate model of survival. Median follow-up for the entire cohort was 50 mo (interquartile range [IQR]: 32–73).

Intervention

All patients underwent PN or RN.

Measurements

We measured OS and cardiac-specific survival.

Results and limitations

Five-year OS estimates for the PN (n = 388) and RN (n = 111) cohorts were 95% (95% confidence interval [CI], 93–98) versus 83% (95% CI, 74–90), respectively (P < 0.0001). On multivariate analysis, controlling for both comorbidity and age, RN was associated with a 2.5-fold increased risk of death compared to PN (hazard ratio [HR]: 2.5; 95% CI, 1.3–5.1). Postoperative estimated glomerular filtration rate (eGFR) was also an independent predictor of OS and cardiac-specific survival (HR: 0.97; 95% CI, 0.95–0.99 and HR: 0.96; 95% CI, 0.93–0.99, respectively). The retrospective nature of this analysis limits the strength of the conclusions.

Conclusions

PN was associated with better OS when compared to RN in patients with unanticipated benign tumours. This observed survival advantage appears partly to be the result of better preservation of eGFR, but other kidney functions or unmeasured factors may also play a role. These data indicate that PN should be aggressively pursued in any patient where PN is technically feasible.     

Laparoscopic versus Open Partial Nephrectomy: Analysis of the Current Literature

Objectives

To critically review the current scientific evidence about open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN) to define the current role of these techniques in the treatment of renal tumours.

Methods

PubMed and Medline were searched for reports about OPN and LPN that were published from 1990 to 2007 and the most relevant papers were reviewed.

Results

OPN is an established curative approach for the treatment of small renal tumours. LPN is challenging and the technique is still under development. The intermediate-term oncologic and functional outcomes of LPN are similar to those of OPN in experienced centres. However, the ischaemia time is longer in laparoscopy and a long learning curve is needed to decrease the risk of complications. In the first phase of a surgeon's experience with LPN, a careful case selection based on the tumour growth pattern is required.

Conclusion

OPN is today the first treatment option for small renal tumours. LPN is technically challenging, but has been shown to achieve similar intermediate-term cancer cure and renal function results in centres with advanced laparoscopic expertise. Larger series with longer follow-up and prospective randomised studies are needed to confirm the safety and efficacy of LPN.     

Thirty-Day Mortality After Nephrectomy: Clinical Implications for Informed Consent

Background

The existing literature suggests that the surgical mortality (SM) observed with nephrectomy for localised disease varies from 0.6% to 3.6%.

Objective

To examine age- and stage-specific 30-d mortality (TDM) rates after partial or radical nephrectomy.

Design, setting, and participants

We relied on 24 535 assessable patients from the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) database.

Measurements

In 12 283 patients, logistic regression models were used to develop a tool for pretreatment prediction of the probability of TDM according to individual patient and tumour characteristics. External validation was performed on 12 252 patients.

Results and limitations

In the entire cohort of 24 535 patients, 219 deaths occurred during the initial 30 d after nephrectomy (0.9% TDM rate). TDM increased with age (≤49 yr: 0.5% vs 50–59 yr: 0.7% vs 60–69 yr: 0.9% vs 70–79 yr: 1.2% vs ≥80 yr: 2.0%; χ² trend p < 0.001) and stage (0.3% for T1–2N0M0 vs 1.3% for T3–4N0–2M0 vs 4.2% for T1–4N0–2M1; χ² trend p = <0.001). TDM decreased in more recent years (1988–1993: 1.3% vs 1994–1998: 0.9% vs 1999–2002: 0.7% vs 2003–2004: 0.6%; χ² trend p < 0.001) and was lower after partial versus radical nephrectomy (RN) (0.4% vs 0.9%; p = 0.008). Only age (p < 0.001) and stage (p < 0.001) achieved independent predictor status. The look-up table that relied on the regression coefficients of age and stage reached 79.4% accuracy in the external validation cohort.

Conclusions

Age and stage are the foremost determinants of TDM after nephrectomy. Our model provides individual probabilities of TDM after nephrectomy, and its use should be highly encouraged during informed consent prior to planned nephrectomy.     

Huge Isolated Port-Site Recurrence after Laparoscopic Partial Nephrectomy: A Case Report

A 66-yr-old man with pain and swelling in the right flank was referred to our clinic for diagnosis. In 2005, the patient underwent a laparoscopic partial nephrectomy for renal cancer of the lower pole of the right kidney. A computed tomography scan revealed a 20-cm tumor in the right abdominal wall, resulting in a suspected diagnosis of port-site metastasis from the first laparoscopic operation. The patient underwent open surgery, which confirmed the diagnosis. After the operation, the patient recovered rapidly.     

Robotic Partial Nephrectomy with Cold Ischemia and On-clamp Tumor Extraction: Recapitulating the Open Approach

We describe a reproducible technique for achieving cold ischemia with intraoperative tumor assessment during robotic partial nephrectomy (RPN) that recapitulates the open approach: intracorporeal cooling and extraction (ICE).     

Laparoscopic Kidney Transplantation

We present the details of the first laparoscopic transplantation of a kidney from a living, related donor, performed April 16, 2009. Surgical and functional results were acceptable. Surgical time was 240 min (53 min for vascular suture), with blood loss of 300 cm³ and a hospital stay of 14 d. Serum creatinine at discharge was 73 mmol/l. Laparoscopic kidney transplantation is a complex technique that requires previous experience in vascular and laparoscopic surgery. As with all novel procedures, technical modifications will be required to formalize its use and detailed comparisons will need to be made with standard procedures.     

Biochemical Recurrence Following Robot-Assisted Radical Prostatectomy: Analysis of 1384 Patients with a Median 5-year Follow-up

Background

There is a paucity of data on long-term oncologic outcomes for patients undergoing robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa).

Objective

To evaluate oncologic outcomes in patients undergoing RARP at a high-volume tertiary center, with a focus on 5-yr biochemical recurrence–free survival (BCRFS).

Design, setting, and participants

The study cohort consisted of 1384 consecutive patients with localized PCa who underwent RARP between September 2001 and May 2005 and had a median follow-up of 60.2 mo. No patient had secondary therapy until documented biochemical recurrence (BCR). BCR was defined as a serum prostate-specific antigen ≥0.2 ng/ml with a confirmatory value. BCRFS was estimated using the Kaplan-Meier method. Event–time distributions for the time to failure were compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression models were used to determine variables predictive of BCR.

Intervention

All patients underwent RARP.

Measurements

BCRFS rates were measured.

Results and limitations

This cohort of patients had moderately aggressive PCa: 49.0% were D’Amico intermediate or high risk on biopsy; however, 60.9% had Gleason 7–10 disease, and 25.5% had ≥T3 disease on final pathology. There were 189 incidences of BCR (31 per 1,000 person years of follow-up) at a median follow-up of 60.2 mo (interquartile range [IQR]: 37.2–69.7). The actuarial BCRFS was 95.1%, 90.6%, 86.6%, and 81.0% at 1, 3, 5, and 7 yr, respectively. In the patients who recurred, median time to BCR was 20.4 mo; 65% of BCR incidences occurred within 3 yr and 86.2% within 5 yr. On multivariable analysis, the strongest predictors of BCR were pathologic Gleason grade 8–10 (hazard ratio [HR]: 5.37; 95% confidence interval [CI], 2.99–9.65; p < 0.0001) and pathologic stage T3b/T4 (HR: 2.71; 95% CI, 1.67–4.40; p < 0.0001).

Conclusions

In a contemporary cohort of patients with localized PCa, RARP confers effective 5-yr biochemical control.     

R-LESS Partial Nephrectomy Trifecta Outcome Is Inferior to Multiport Robotic Partial Nephrectomy: Comparative Analysis

Background

Trifecta achievement in partial nephrectomy (PN) is defined as the combination of warm ischemia time ≤20 min, negative surgical margins, and no surgical complications.

Objective

To compare trifecta achievement between robotic, laparoendoscopic, single-site (R-LESS) PN and multiport robotic PN (RPN).

Design, setting, and participants

Data from 167 patients who underwent RPN from 2006 to 2012 were retrospectively analyzed.

Outcome measurements and statistical analysis

Primary outcome measurement was trifecta achievement; secondary outcome was the perioperative and postoperative comparison between groups. The measurements were estimated and analyzed with SPSS v.18 using univariable, multivariable, and subgroup analyses.

Results and limitations

Eighty-nine patients were treated with RPN and 78 were treated with R-LESS PN. Baseline characteristics of both groups were similar. Trifecta was achieved in 38 patients (42.7%) in the multiport RPN group and 20 patients (25.6%) in the R-LESS PN group (p = 0.021). Patients in the R-LESS PN group had longer mean operative time, warm ischemia time, and increased estimated glomerular filtration rate (eGFR) percentage change. No significant differences were found between the two groups in days of hospitalization, blood loss, postoperative eGFR, positive surgical margins, and surgical complications. Patients with increased PADUA and RENAL scores, infiltration of the collecting system, and renal sinus involvement had an increased probability of not achieving the trifecta. In regression analysis, the type of procedure and the tumor size could predict trifecta accomplishment (p = 0.019 and 0.043, respectively). The retrospective study, the low number of series, and the controversial definition of trifecta were the main limitations.

Conclusions

The trifecta was achieved in significantly more patients who underwent multiport RPN than those who underwent R-LESS PN. R-LESS PN could be an alternative option for patients with decreased tumor size, low PADUA and RENAL scores, and without renal sinus or collecting system involvement.

Patient summary

In this study, we looked at the outcomes of patients who had undergone robotic partial nephrectomy. We found that conventional robotic partial nephrectomy is superior to R-LESS partial nephrectomy with regard to the accomplishment of negative margins, reduced warm ischemia time, and minimal surgical complications.     

Laparoscopic and Robotic Assisted Radical Cystectomy for Bladder Cancer: A Critical Analysis

Context and Objectives

Interest in laparoscopic assisted radical cystectomy (LRC) and robotic assisted radical cystectomy (RRC) is increasing at select centers worldwide. In this update we present the recent worldwide experience and critically evaluate the role of minimally invasive radical surgery for patients with bladder cancer.

Evidence Acquisition

English-language literature between 1992 and 2007 was reviewed using the National Library of Medicine database and the following key words: laparoscopic, laparoscopic-assisted, robotic, robotic-assisted, and radical cystectomy. Over 102 papers were identified, 48 of which were selected for this review on the basis of their contribution to advancing the field with regard to three criteria: (1) evolution of concepts, (2) development and refinement of techniques, and (3) intermediate- and long-term clinical outcomes. These were evaluated with respect to current techniques and perioperative, functional, and oncological outcomes. Our initial experience is also reported.

Evidence Synthesis

Minimally invasive techniques can adequately achieve the extirpative aspects of LRC and extended template lymphadenectomy. At most institutions the reconstructive urinary diversion is now typically being performed extracorporeally through a minilaparotomy. Perioperative data indicate that minimally invasive techniques are associated with reduced blood loss, slightly increased operating time, and shorter hospital stay without any significant difference in postoperative complications compared with open surgery. Intermediate-term oncological outcomes appear to be comparable with the open approach. Worldwide experience continues to increase; >700 surgeries have already been performed.

Conclusion

LRC or RRC with extracorporeally constructed urinary diversion is a safe and effective operation for appropriate patients with bladder cancer. Perioperative and functional outcomes are comparable with open surgery. More focus on extended lymphadenectomy is necessary to routinely achieve higher node yields. Surrogate and intermediate oncological outcomes are encouraging, and long-term assessment is ongoing.     

Assessment of Risk Factors for Complications of Laparoscopic Partial Nephrectomy

Objective

Laparoscopic partial nephrectomy (LPN) is a technique that is emerging as an attractive option for the treatment of renal tumors ≤4 cm. We retrospectively analyzed our experience with LPN to identify patient and tumor features that correlate with a higher risk of complications.

Material and methods

From January 2001 to May 2007, 90 patients underwent LPN at our institution for a clinically localized renal tumor. A retrospective chart review was carried out. Clinical and pathological information were collected for each patient, including patient age and body mass index, tumor size, location and pattern of growth (cortical vs. corticomedullar), surgical approach (transperitoneal vs. retroperitoneal), warm ischemia time, technique that was used to achieve hemostasis, maximum thickness of the margin of resection, and histology. Statistical analysis (chi-square test, Fisher exact test, Mann-Whitney U test, linear regression model) was performed to test the correlation between the above-mentioned variables and the occurrence of complications.

Results

Twenty-two patients (24.4%) had surgical and/or medical complications in our series. The only variable that was found to significantly correlate with a higher number of complications was a corticomedullar tumor growth pattern as opposed to a cortical growth pattern (p = 0.02).

Conclusions

LPN is an attractive alternative to open partial nephrectomy for the treatment of small renal tumors. On the basis of our experience, the selection of patients with cortical renal lesions seems to be required to reduce the risk of complications and therefore maximize the advantages of this minimally invasive but challenging procedure.     

Vascular Anomalies During Laparoscopic Renal Surgery: Incidence and Management of Left-Sided Inferior Vena Cava

Background:

Left-sided inferior vena cava (IVC) is an unusual abnormality that may be clinically significant during renal surgery.

Methods:

We report the unique case of a patient with a centrally located left renal mass who underwent laparoscopic radical nephrectomy. During the hilar dissection, unusual vascular anatomy was encountered. The patient was noted to have a left-sided inferior vena cava with multiple renal veins and anomalous tributaries. Laparoscopic radical nephrectomy was performed without complication.

Discussion:

The embryology of a left-sided inferior vena cava is reviewed, and the safety and feasibility of a laparoscopic approach is discussed.     

Laparo-Endoscopic Single-Site Left Transperitoneal Adrenalectomy

A 53-yr-old woman presented with abdominal pain. Ultrasonography, computed tomography, and an endocrinologic work-up revealed a 4-cm nonfunctional left adrenal mass. A TriPort laparoscopic adrenalectomy was performed.     

Retropubic,Laparoscopic, and Robot-Assisted Radical Prostatectomy: A Systematic Review and Cumulative Analysis of Comparative Studies

Context

Despite the wide diffusion of laparoscopic radical prostatectomy (LRP) and robot-assisted laparoscopic radical prostatectomy (RALP), only few studies comparing the results of these techniques with the retropubic radical prostatectomy (RRP) are currently available.

Objective

To evaluate the perioperative, functional, and oncologic results in the comparative studies evaluating RRP, LRP, and RALP.

Evidence acquisition

A systematic review of the literature was performed in January 2008, searching Medline, Embase, and Web of Science databases. A “free-text” protocol using the term radical prostatectomy was applied. Some 4000 records were retrieved from the Medline database; 2265 records were retrieved from the Embase database;, and 4219 records were retrieved from the Web of Science database. Three of the authors reviewed the records to identify comparative studies. A cumulative analysis was conducted using Review Manager software v.4.2 (Cochrane Collaboration, Oxford, UK).

Evidence synthesis

Thirty-seven comparative studies were identified in the literature search, including a single, randomised, controlled trial.With regard to the perioperative outcome, LRP and RALP were more time consuming than RRP, especially in the initial steps of the learning curve, but blood loss, transfusion rates, catheterisation time, hospitalisation duration, and complication rates all favoured LRP. With regard to the functional results, LRP and RRP showed similar continence and potency rates. Similarly, no significant differences were identified between LRP and RALP, while a single, nonrandomised, prospective study suggested advantages in terms of both continence and potency recovery after RALP, compared with RRP. With regard to the oncologic outcome, LRP and RALP were associated with positive surgical margin rates similar to those of RRP.

Conclusions

The quality of the available comparative studies was not excellent. LRP and RALP are followed by significantly lower blood loss and transfusion rates, but the available data were not sufficient to prove the superiority of any surgical approach in terms of functional and oncologic outcomes. Further high-quality, prospective, multicentre, comparative studies are needed.     

Complete Histologic Remission after Sunitinib Neoadjuvant Therapy in T3b Renal Cell Carcinoma

The authors present the first case report of complete histologic remission after neoadjuvant sunitinib treatment on primary renal tumour and vena cava thrombus. A 78-yr-old woman with an Eastern Cooperative Oncology Group (ECOG) score of 0 presented with a T3b renal tumour. She refused surgical treatment but agreed to percutaneous biopsy and medical treatment. A Fuhrman III renal cell carcinoma was histologically confirmed on percutaneous biopsy, and sunitinib treatment was administered over 6 mo. A significant objective response was observed for tumour size and thrombus. The patient finally accepted surgical treatment. Pathologic examination concluded with a complete response of primary tumour and thrombus.     

Successful Sorafenib Treatment for Metastatic Renal Cell Carcinoma in a Case with Chronic Renal Failure

Treatment options for patients with end-stage renal disease (ESRD) and metastatic renal cell carcinoma (mRCC) are limited. We report the case of a 69-yr-old male who was treated with sorafenib after failure of immunotherapy. The treatment has resulted in remission with stable disease for 13 mo so far. Sorafenib seems to be a safe treatment option for patients with ESRD and mRCC, but further studies are required.     

Comprehensive Standardized Report of Complications of Retropubic and Laparoscopic Radical Prostatectomy

Background

The lack of standardized reporting of the complications of radical prostatectomy in the literature has made it difficult to compare incidences across institutions and across different surgical approaches.

Objective

To define comprehensively the incidence, severity, and timing of onset of medical and surgical complications of open retropubic prostatectomy (RP) and laparoscopic radical prostatectomy (LP) using a standardized reporting methodology to facilitate comparison.

Design, setting, and participants

Between January 1999 and June 2007, 4592 consecutive patients underwent RP or LP without prior radiation or hormonal therapy. Median follow-up was 36.9 mo (interquartile range: 20.3–60.6).

Intervention

Open or laparoscopic radical prostatectomy.

Measurements

All medical and surgical complications of radical prostatectomy were captured and graded according to the modified Clavien classification and classified by timing of onset.

Results and limitations

There were 612 medical complications in 467 patients (10.2%) and 1426 surgical complications in 925 patients (20.1%). The overall incidences of early minor and major medical and surgical complications for RP were 8.5% and 1.5% for medical and 11.4% and 4.9% for surgical complications, respectively. The overall incidences of early minor and major medical and surgical complications for LP were 14.2% and 2.3% for medical and 23.1% and 6.6% for surgical complications, respectively. On multivariate analysis, LP approach was associated with a higher incidence of any grade medical and surgical complications but a lower incidence of major surgical complications than RP. Six hundred fifty-two men (14.2%) visited the emergency department, and 240 men (5.2%) required readmission. The main limitation is the retrospective nature.

Conclusions

With standardized reporting, the incidence of some complications is higher than recognized in the literature. Although most complications are minor in severity, medical and surgical complications are observed in approximately 10% and 20% of patients, respectively. Accurate reporting of complications through a standardized methodology is essential for counseling patients regarding risk of complications, for identifying modifiable risk factors, and for facilitating comparison across institutions and approaches.     

Long-Term Rates of Undetectable PSA with Initial Observation and Delayed Salvage Radiotherapy after Radical Prostatectomy

Background

Randomized trials have shown an improvement in progression-free survival rates with adjuvant radiation therapy (ART) after radical prostatectomy for patients with a high risk of cancer recurrence. Less is known about the relative advantages and disadvantages of initial observation with delayed salvage radiation therapy (SRT).

Objective

To examine the results of SRT in a large single-surgeon radical prostatectomy series.

Design, Setting, and Participants

From a radical prostatectomy database, we identified 859 men with positive surgical margins (SM+), extracapsular tumor extension (ECE), or seminal vesicle invasion (SVI) who chose to defer ART. Following a period of initial observation, 192 ultimately received SRT for prostate-specific antigen (PSA) progression.

Measurements

Survival analysis was performed to examine the outcomes of initial observation followed by SRT.

Results and Limitations

In patients with SM+/ECE and SVI, the 7-yr PSA progression-free survival rates with observation were 62% and 32%, respectively. Among those who had PSA progression, 56% and 26%, respectively, maintained an undetectable PSA for 5 yr after SRT. The long-term rates of undetectable PSA associated with an SRT strategy were 83% and 50% for men with SM+/ECE and SVI, respectively. In the subset of 716 men who did not receive any hormonal therapy, the corresponding long-term rates of undetectable PSA were 91% and 75%, respectively.

Conclusions

Following radical prostatectomy, initial observation followed by delayed SRT at the time of PSA recurrence is an effective strategy for selected patients with SM+/ECE. Some patients with SVI may also benefit from this strategy. However, additional prospective studies are necessary to further examine the survival outcomes following SRT.     

Predicting Occult Multifocality of Renal Cell Carcinoma

Background

Multifocal renal cell carcinoma (RCC) has been reported in up to 25% of all radical nephrectomy specimens. Modern imaging tends to underestimate the rate of multifocality. Recognition of multifocality before treatment may guide physicians and patients to the type of intervention and tailor long-term follow-up.

Objective

Our aim was to develop and assess preoperative nomograms to predict occult multifocal RCC.

Design, setting, and participants

We evaluated 560 consecutive patients undergoing radical nephrectomy for clinically localized suspected sporadic RCC between 2000 and 2008 in a tertiary center. Clinically manifest multifocal lesions were excluded. Logistic regression models were used to assess the potential risk factors of occult multifocality with and without pathologic variables that may be available with preoperative biopsy. Nomograms were developed and assessed for diagnostic properties.

Interventions

All patients underwent radical nephrectomy.

Measurements

Assessments of risk factors for occult multifocal RCC were obtained using regression models and nomograms.

Results and limitations

The incidence of occult multifocality was 7.9%. Significantly associated predictors of multifocality were male gender, family history of malignancy other than RCC, radiographic size of the lesion, histologic subtype other than clear cell, and Fuhrman grade IV. The two designed nomograms had 0.75 and 0.82 concordance indices, respectively.

Conclusions

Our data suggest that occult multifocal RCC is more frequently associated with small (2–4 cm) renal lesions. Male gender, family history of kidney cancer, histologic subtype, and grade are strongly associated with an increased risk of occult multifocal RCC. The developed nomograms had good predictive accuracy that was enhanced when combined with pathologic variables.     

Renal Tumor Contact Surface Area: A Novel Parameter for Predicting Complexity and Outcomes of Partial Nephrectomy

Background

The contact surface area (CSA) of a tumor with adjacent renal parenchyma may determine the complexity and thus the perioperative outcomes of partial nephrectomy (PN).

Objective

We devised a novel imaging parameter, renal tumor CSA, and correlate it with perioperative outcomes in patients undergoing PN.

Design, setting, and participants

Of 200 patients undergoing PN for a tumor (January 2010 to August 2011), 162 had renal protocol computed tomography scanning data available. CSA was calculated using image-rendering software (Synapse 3D, Fujifilm), and interobserver variability was determined between three independent observers.

Outcome measurements and statistical analysis

CSA was correlated to baseline demographics and perioperative outcomes as a continuous and categorical variable using multivariable logistic regression analysis. The ability of CSA to predict adverse perioperative events was compared with demographic factors and nephrometry scoring systems.

Results and limitations

The mean tumor size was 3.1 cm; CSA was 18.3 cm². CSA ≥20 cm² correlated with adverse tumor characteristics (greater tumor size, volume, and complexity) and perioperative outcomes (more parenchymal volume loss, blood loss, and complications) compared with CSA <20 cm². On multivariable logistic regression, CSA independently predicted operative time, complications, hospital stay, and renal functional outcomes. This predictive ability of CSA was superior to the other parameters evaluated.

Conclusions

CSA is a novel imaging parameter that quantifies the CSA of renal tumor with adjacent parenchyma. Our preliminary data indicate that CSA correlates with PN outcomes. If validated externally in a larger cohort, CSA could be incorporated into future versions of nephrometry scoring systems.

Patient summary

In this study we outline the method of calculating the contact surface area (CSA) of renal tumors with the surrounding normal kidney using image-rendering software. We found that CSA correlates with a number of important surgical outcomes including operative time, loss of renal function, and complications.