Laparoscopic Partial Nephrectomy for Tumors Larger Than 4 cm: A Comparative Study

Oncological and functional outcomes of open versus laparoscopic partial nephrectomy in T1b tumors: A single-center analysis

PURPOSE

This study aims to evaluate the oncological and functional results of open partial nephrectomy (OPN) and laparoscopic partial nephrectomy (LPN) at the T1b clinical stage, which constitutes 25% of renal cell carcinomas (RCC) at diagnosis.

MATERIALS AND METHODS

The characteristics of 63 patients with stage T1b solitary tumor who underwent OPN (41) or LPN (22) were compared. The survival analysis was performed using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to determine the factors affecting disease-free survival. Potential predictive factors, which might affect the postoperative glomerular filtration rate (GFR), were evaluated using multivariate linear regression analysis.

RESULTS

No differences were observed between OPN and LPN groups regarding patient and tumor characteristics. Although the warm ischemia time, intraoperative estimated blood loss, and operation duration were higher in the LPN group, no differences were noted between the two techniques regarding complication rates (p<0.001, p=0.023, p≤0.001, and p=0.190, respectively). The median hospitalization time was shorter in the LPN group than that in the OPN group (4 and 5 days, respectively), with less severe complications. No intergroup differences were observed regarding cancer-specific survival (CSS), disease-free survival (DFS), and overall survival (OS). The evaluation of the factors affecting DFS showed that age was an effective parameter (RR = 1.112, 95% CI: 1.010-8.254), but the surgical technique was not.

CONCLUSION

No differences were observed between OPN and LPN techniques between oncological and functional outcomes in patients with clinical stage T1b RCC.

Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors: a modified R.E.N.A.L nephrometry score adjusted comparison

BACKGROUND

Comparable oncological outcomes have been seen after surgical nephrectomy and thermal ablation of renal tumors recently. However, periprocedural outcome needs to be assessed for aiding treatment decision.

PURPOSE

To compare efficacy rates and periprocedural outcome (technical success, session time, hospitalization time, and complications) after renal tumor treatment with laparoscopic partial nephrectomy (LPN) or radiofrequency ablation (RFA).

MATERIAL AND METHODS

The initial experience with 49 (treated with LPN) and 84 (treated with RFA) consecutive patients for a single renal tumor (diameter ≤ 5 cm, limited to the kidney) during 2007-2014 was evaluated. Patient and tumor characteristics, efficacy rates, and periprocedural outcome were collected retrospectively. The stratified Mantel Haenzel and Van Elteren tests, adjusted for tumor complexity (with the modified R.E.N.A.L nephrometry score [m-RNS]), were used to assess differences in treatment outcomes.

RESULTS

Primary efficacy rate was 98% for LPN and 85.7% for RFA; secondary efficacy rate was 93.9% for LPN and 95.2% for RFA; and technical success rate was 87.8% for LPN and 100% for RFA. Median session (m-RNS adjusted P < 0.001; LPN 215 min, RFA 137 min) and median hospitalization time were longer after LPN (m-RNS adjusted P < 0.001; LPN 5 days, RFA 2 days). Side effects were uncommon (LPN 2%, RFA 4.8%). Complications were more frequent after LPN (m-RNS adjusted P < 0.001; LPN 42.9%, RFA 10.7%).

CONCLUSION

Both methods achieved equivalent secondary efficacy rates. RFA included several treatment sessions, but session and hospitalization times were shorter, and complications were less frequent than for LPN. The differences remained after adjustment for renal tumor complexity.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Treatment outcomes of partial nephrectomy for T1b tumours

PURPOSE OF REVIEW

Nephron-sparing surgery is the standard of care for the treatment of localized renal tumours and is increasingly performed for larger and more challenging lesions. Aim of this review is to analyse the outcomes of partial nephrectomy for the treatment of T1b renal tumours greater than 4 cm in size.

RECENT FINDINGS

No randomized trial has compared the outcomes of partial nephrectomy compared to radical nephrectomy for T1b renal tumours. However, several single, multi-institutional and population-based studies consistently showed similar cancer-specific survival rates for open partial nephrectomy (OPN) and radical nephrectomy for tumours greater than 4 cm in size. A decreased loss in renal function was observed with partial nephrectomy compared to radical nephrectomy for T1b tumours. Laparoscopic partial nephrectomy (LPN) for tumours greater than 4 cm in size was shown to obtain similar short-to-intermediate-term oncological outcomes of laparoscopic radical nephrectomy and OPN in experienced centres, but is associated with longer warm ischaemia time and higher complication rates. The initial series of robot-assisted partial nephrectomy show similar perioperative results and decreased warm ischaemia time compared to LPN, whereas the oncological outcomes are still immature.

SUMMARY

Partial nephrectomy for T1b renal tumours achieves comparable oncological outcomes and better preservation of renal function compared to radical nephrectomy and should be performed whenever technically possible. OPN remains at present the gold standard technique. LPN represents an alternative to OPN in centres with advanced laparoscopic expertise. Robot-assisted partial nephrectomy has the potential to overcome the drawbacks of pure laparoscopic surgery, but larger series and longer follow-up are needed to further define its role in the management of T1b tumours.

Laparoscopic partial nephrectomy: An experience in 227 cases

OBJECTIVE

To evaluate our long-term experience with laparoscopic partial nephrectomy (LPN) and to review the literature.

MATERIAL AND METHODS

We performed a retrospective chart review, evaluating 227 consecutives laparoscopic partial nephrectomies performed between June 1995 and June 2010. Perioperative were recorded along with clinical a oncological outcomes.

RESULTS

Mean age was 56.4 years (18-87) and clinical stages were T1a, T1b and T2 in 90.74% (206/227), 7.48% (17/227) and 1.76% (4/227), respectively. Median blood loss was 250 mL (10-1800). The mean operative time was 108.42 minutes (30-240) and median warm ischemia time was 25 minutes (10-60). The intraoperative complication rate was 2.64% (6/227), 5 (2.2%) secondary to bleeding. The postoperative complication rate was 5.72% (13/227) and bleeding is also the most frequent in 3% (7/227) of the cases. According to the Clavien classification, 1.32% (3/227), 0.88% (2/227) and 3.52% (8/227) were grade I, II and IIIb, respectively. The mean hospital stay was 3.66 days (1-12). Clear cell carcinoma was the most common histological finding in 74.6% (150 patients). TNM clasification was T1a, T1b y T2 in 90.74% (206/227), 7.48% (17/227) and 1,76% (4/227), respectively. No conversion or mortality was reported. Positive surgical margins were found in 4 patients (2.7%), with no local recurrence after long-term follow-up. At a mean follow up of 27 months, one patient had port site and peritoneal recurrence.

CONCLUSION

Laparoscopic partial nephrectomy is a safe and viable alternative to open partial nephrectomy, providing equivalent oncologic outcomes and comparable morbidity to the traditional approach in experienced centers.

Risk factors for postoperative hemorrhage after partial nephrectomy

Purpose

To evaluate the frequency and clinical characteristics of postoperative hemorrhage as a complication of partial nephrectomy.

Materials and Methods

The demographics, physical statistics, tumor size, R.E.N.A.L. nephrometry score, operative method, warm ischemic time, and presence of postoperative hemorrhage and its severity and method of intervention were examined in 300 partial nephrectomy patients in two medical centers (Stanford Medical Center and Kyung Hee University Medical Center) between March 2000 and March 2012.

Results

Of the 300 subjects, 13 (4.3%) experienced postoperative hemorrhage severe enough to require intervention more invasive than transfusion (Clavien grade III or higher). Univariate analysis of the bleeding and nonbleeding groups showed that whereas age, ischemic time, tumor size and stage, body mass index, American Society of Anesthesiologists class, and operative method did not differ significantly, the exophyticity (E) score was significantly higher for severe postoperative hemorrhage (p=0.04). However, multivariate analysis showed none of the factors to differ significantly. In most of the cases requiring intervention, selective embolization was sufficient, but in one case explorative laparotomy and nephrectomy were required. Clinical characteristics varied significantly among severe hemorrhage cases, with time of onset ranging from the first to the 30th postoperative day and symptoms presenting in a diverse manner, such as gross hematuria and pleuritic chest pain. Computed tomography and angiographic findings were consistent with either arteriovenous fistula or pseudoaneurysms.

Conclusions

Severe hemorrhage after partial nephrectomy is rare. Nonetheless, with the great variability in presenting symptoms and time of onset after surgery, surgeons should exercise great vigilance during the postoperative care of partial nephrectomy patients.

Comparison between laparoscopic and open partial nephrectomy: surgical, oncologic, and functional outcomes

The surgical, oncologic, and functional outcomes were retrospectively compared of laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) for the treatment of renal masses. Between January 2006 and November 2011, 115 LPNs and 97 OPNs were performed. The patients' demographics were matched. Their intraoperative and postoperative data, oncologic and renal function outcomes were compared. Surgical time, renal arterial occlusion time, estimated blood loss, and postoperative hospitalization days were shorter in the LPN group (p < 0.01). The total complications were comparable; however, LPN had a higher intraoperative complication due to 12 subcutaneous emphysemas. The LPN group was followed up with a mean time of 29.3 ± 14.4 months and the OPN group with a mean time of 31.2 ± 12.6 months. All patients survived and no distant relapse or metastasis were observed. Kaplan-Meier estimates of 60-month local recurrence-free survival were comparable with 92.4% after LPN and 93.8% after OPN, respectively (p = 0.57). The reduction of glomerular filtration rate was more obvious after LPN at the 3-month follow-up (p < 0.01), but similar between the two groups at the 30.2-month follow-up. LPN provides similar results in oncologic and functional outcomes when compared to OPN. Long-term observations are still required to the oncologic and function outcomes.

Robotic and laparoscopic partial nephrectomy for T1b tumors

PURPOSE OF REVIEW

Laparoscopic and robotic-assisted partial nephrectomy have been widely adopted for the management of small renal masses; however, usage in T1b (greater than 4 cm) lesions is less established. Herein, we report a review on the published series of minimally invasive partial nephrectomies for such renal masses.

RECENT FINDINGS

Several institutions have described laparoscopic and robotic-assisted partial nephrectomy as a safe management option for pathologic T1b lesions. The oncologic results are promising, with low positive margin rates and few cases of progressive disease. Longer-term renal dysfunction does not appear at an increasing rate in this cohort of patients. The safety profile appears acceptable; however, there is a slightly increased rate of complications in these cohorts of patients.

SUMMARY

Laparoscopic and robotic-assisted partial nephrectomy is a well tolerated and viable option for performing minimally invasive surgical extirpation of cT1b renal masses. The oncologic and functional results are excellent with acceptable safety profiles. In patients with such masses minimally invasive partial nephrectomy should be considered for elective and absolute indications. In order to achieve excellent functional and oncologic outcomes with minimal perioperative complications an experienced surgeon with assistant and assessment of tumor with patient comorbidities are important.

Laparoscopic partial nephrectomy for >4 cm renal masses

INTRODUCTION

Laparoscopic partial nephrectomy (LPN) is frequently used to manage cT1a renal masses. While data on safety and long-term oncological outcomes of LPN for T1a tumours are widely available, it is limited for >T1a lesions. We report our experience with LPN for >4 cm renal masses from a Canadian tertiary centre.

METHODS

Between January 2003 and July 2011, 52 consecutive LPN for >4 cm renal masses were performed. Demographic, pathological and clinical data were obtained from a prospectively maintained database.

RESULTS

The mean patient age was 60 years (62% male). Median tumour size was 4.8 (range: 4.2-11) cm. The median surgical time was 145 minutes, and the median estimated blood loss was 100 mL. The median warm ischemia time was 24 minutes. Four (7.7%) cases required conversion to open surgery. One case was converted to total nephrectomy for clinical and pathological evidence of T3 disease. The surgical margin was positive in 1 case (1.9%). Four (7.7%) patients developed a urine leak postoperatively; 3 of them managed with a ureteric stent. Four (7.7%) patients developed postoperative bleeding requiring selective angioembolization. The median hospital stay was 4 days. There was no statistically significant difference between preoperative and postoperative estimated glomerular filtration rate and mean arterial blood pressure (p = 0.5, p = 0.1, respectively).

CONCLUSION

This series demonstrates that LPN although technically challenging has acceptable short-term surgical outcomes. Long-term assessment of oncological outcomes is required. Laparoscopic partial nephrectomy >4 cm renal tumours should not be considered a standard of care, but excellent results can be achieved in well-selected patients and in experienced hands with no impact in renal function or blood pressure.

Novel high-intensity focused ultrasound clamp--potential adjunct for laparoscopic partial nephrectomy

BACKGROUND AND PURPOSE

Partial nephrectomy (PN) can be technically challenging, especially if performed in a minimally invasive manner. Although ultrasound technology has been shown to have therapeutic capabilities, including tissue ablation and hemostasis, it has not gained clinical use in the PN setting. The purpose of this study is to evaluate the ability of a high-intensity ultrasound clamp to create an ablation plane in the kidney providing hemostasis that could potentially aid in laparoscopic PN.

METHODS

A new instrument was created using a laparoscopic Padron endoscopic exposing retractor. Ultrasound elements were engineered on both sides of the retractor to administer high-intensity ultrasound energy between the two sides of the clamp. This high-intensity focused ultrasound (HIFU) clamp was placed 2 to 2.5 cm from the upper and lower poles of 10 porcine kidneys to evaluate its effectiveness at different levels and duration of energy delivery. PN transection was performed through the distal portion of the clamped margin. Kidneys postintervention and after PN were evaluated and blood loss estimated by weighing gauze placed at the defect. Histologic analysis was performed with hematoxylin and eosin and nicotinamide adenine dinucleotide staining to evaluate for tissue viability and thermal spread.

RESULTS

Gross parenchymal changes were seen with obvious demarcation between treated and untreated tissue. Increased ultrasound exposure time (10 vs 5 and 2 min), even at lower power settings, was more effective in causing destruction and necrosis of tissue. Transmural ablation was achieved in three of four renal units after 10 minutes of exposure with significantly less blood loss (<2 g vs 30-100 g). Nonviable tissue was confirmed histologically. There was minimal thermal spread outside the clamped margin (1.2-3.2 mm).

CONCLUSION

In this preliminary porcine evaluation, a novel HIFU clamp induced hemostasis and created an ablation plane in the kidney. This technology could serve as a useful adjunct to laparoscopic PN in the future and potentially obviate the need for renal hilar clamping.

Laparoscopic partial nephrectomy: risk stratification according to patient and tumor characteristics

PURPOSE

Laparoscopic partial nephrectomy (LPN) is the treatment of choice for localized tumors in many centers. We aimed to evaluate differences in complication rates and outcome stratified by risk categories, depending on patient or tumor characteristics.

METHODS

Eighty-one patients who underwent LPN for localized renal tumors between 2004 and 2007 were evaluated. Clinical and pathological data, including localization, size and infiltration depth (classified according to PADUA and RENAL score), at initial radiologic imaging were analyzed. Results were correlated with complications during or after surgery, operative time, warm ischemia time and clinical outcome.

RESULTS

Overall complication rate was 13.6% for LPN (11 patients, Clavien-Dindo classification: II-III). No significant correlations were found for patient-based risk classification models (age > 70 years, ASA-status >2, BMI > 30). A higher mean operative time was observed in centrally located tumors (P = 0.045). Increased hemoglobin loss was observed in central (P = 0.007), PADUA > 8 (P = 0.006) and RENAL > 7 (P = 0.002) tumors. Impaired renal function (creatinine increase in postoperative controls) was associated with tumor diameter > 4 cm (P = 0.023). Only central tumor growth had a significant predictive value for postoperative complications (P = 0.007). In patients with central tumor growth (P = 0.002), PADUA > 8 (P = 0.041) and RENAL > 7 (P = 0.044) scores, hospital stay was prolonged.

CONCLUSIONS

Uni and multifactorial scoring systems have been developed for LPN to identify potentially high-risk patients. In our series, only central tumor growth pattern enabled the prediction of increased operation time, hemoglobin loss, hospitalization as well as postoperative complications.

Oncological outcomes of partial nephrectomy for renal carcinoma greater than 4 cm

PURPOSE OF REVIEW

To provide the clinical evidence and benefits of performing partial nephrectomy for renal tumors greater than 4 cm.

RECENT FINDINGS

Partial nephrectomy was historically performed only for the essential indications of a tumor in a functional or anatomical solitary kidney or in the face of bilateral renal tumors. Partial nephrectomy has now emerged as an oncologically equivalent operation to radical nephrectomy for T1a tumors (<4 cm) with the added benefit of renal functional preservation which can prevent or delay the onset of chronic kidney disease (CKD). CKD is an independent risk factor for hospitalization events, cardiovascular disease, and worse overall survival. Recent evidence has demonstrated that partial nephrectomy also provides equivalent oncological results for larger renal tumors including those of 4-7 cm and even for greater than 7 cm, whenever technically feasible with the continued added benefit of renal functional preservation. Partial nephrectomy is effectively performed using both open surgical techniques and increasingly by minimally invasive approaches although the latter is technically challenging.

SUMMARY

Despite the mounting clinical evidence that partial nephrectomy is an effective and preferable approach to the T1 renal mass, it remains markedly underutilized in the USA and abroad. The overzealous use of radical nephrectomy for the T1 renal mass, by whatever surgical approach, must now be considered detrimental to the long-term health of the kidney tumor patient.