Selective Renal Parenchymal Clamping in Robot-Assisted Laparoscopic Partial Nephrectomy: A Multi-Institutional Experience

Robotic-Assisted Partial Nephrectomy: Techniques to Improve Clinical Outcomes

PURPOSE OF REVIEW

To summarize current options available for robot-assisted partial nephrectomy RECENT FINDINGS: Partial nephrectomy (PN) is a standard treatment option for management of cT1 renal masses. It may be carried out by multiple approaches. Robot-assisted (RA) PN is one such option. The goal of treatment is both correct oncological (negative surgical margins) and functional (preservation of sufficient amount of renal parenchyma of the operated kidney) outcome. Appropriate outcomes depend on multiple factors. There are many, but among others tumor characteristics (size, location, i.e., tumor complexity), patient baseline renal function, patient comorbidities, and performance status etc. Based on all these, the surgeon adapts the intervention for each mass/patient by preoperative planning, absence/use/duration of warm or cold ischemia, perioperative imaging, resection technique adapted to tumor location and depth of invasion, use of hemostatics, type and degree of renal parenchymal closure and others details. Nephroprotective agents have not shown efficacy so far. It should not be forgotten that surgeon's experience plays a key role in the achievement of good results. Although multiple factors have a role in the RA partial nephrectomy, surgeon experience and adaptation of technique of intervention have the crucial role in the achievement of both functional and oncological results.

Robot-assisted partial nephrectomy: How to minimise renal ischaemia

Renal ischaemia research has shown an increase in renal damage proportional to ischaemic time. Therefore, we assessed the importance of renal ischaemic times for warm and cold ischaemia approaches, and explored the different surgical techniques that can help to minimise renal ischaemia in robot-assisted partial nephrectomy (RAPN). Minimising renal ischaemia during nephron-sparing surgery (NSS) is a key factor in preserving postoperative renal function. Current data support a safe warm ischaemia time (WIT) of ≤25 min and cold ischaemic time of ≤35 min, resulting in no significant deterioration in renal function. In general, patients undergoing NSS have increased comorbidities, including chronic kidney disease, and in these patients it is difficult to predict their postoperative renal function recovery. With RAPN, efforts should be made to keep the WIT to <25 min, as minimising the ischaemic time is vital for preservation of overall renal function and remains a modifiable risk factor. Parenchymal or segmental artery clamping, early unclamping or off-clamp techniques can be adopted when ischaemic times are likely to be >25 min, but may not lead to superior functional outcome. Careful preoperative planning, tumour factors, and meticulous surgical technique are critical for optimum patient outcome.

Laparoscopic Partial Nephrectomy: A Narrative Review and Comparison with Open and Robotic Partial Nephrectomy

INTRODUCTION

Kidney cancer ranks among the top 10 most prevalent cancers in Western society, ∼90% of which are renal cell carcinomas. There has been a paradigm shift in the management of small renal masses with strong emphasis now placed on nephron-sparing surgery and increased utilization of laparoscopic approaches to partial nephrectomy. In this review, the current state of laparoscopic partial nephrectomy (LPN) is discussed.

EVIDENCE ACQUISITION

The PubMed database was queried using the MeSH terms "laparoscopy" and "nephrectomy," as well as the search term "partial." A search was performed filtering for "clinical trial," "review," "humans", and "English."

EVIDENCE SYNTHESIS

Articles that discussed intraoperative techniques, functional and oncologic outcomes, and a comparison between robot-assisted partial nephrectomy and LPN were synthesized.

CONCLUSION

LPN reduces ischemia time, affords equivalent functional outcomes, oncologic outcomes, and equivalent complication rates compared with open partial nephrectomy. Future advances in laparoscopic technique and advancements in robotic technology offer potential to improve surgical and patient outcomes.

Optimising renal cancer patients for nephron-sparing surgery: a review of pre-operative considerations and peri-operative techniques for partial nephrectomy

Nonmodifiable factors including pre-operative renal function and amount of healthy renal tissue preserved are the most important predictive factors that determine renal function after partial nephrectomy. Ischaemia time is an important modifiable risk factor and cold ischaemia time should be used if longer ischaemia time is anticipated. New techniques may have a role in maximising postoperative kidney function, but more robust studies are required to understand their potential benefits and risks.

Renal Functional and Perioperative Outcomes of Selective Versus Complete Renal Arterial Clamping During Robot-Assisted Partial Nephrectomy: Early Single-Center Experience With 39 Cases

OBJECTIVE

The objective of this study was to investigate clinical outcomes in patients undergoing selective versus conventional complete renal arterial clamping during robot-assisted partial nephrectomy (RAPN).

METHODS

This study included 19 patients with renal tumors who received RAPN incorporating selective arterial clamping (group 1). The renal functional as well as perioperative outcomes in group 1 were compared with those in 20 patients with renal tumors undergoing RAPN with total clamping of the renal artery (group 2) during the same period.

RESULTS

In group 1, tumor resection under selective arterial clamping could be completed in all patients without intraoperative conversion to conventional RAPN with total clamping. There were no significant differences in the tumor size, RENAL nephrometry score, or preoperative estimated glomerular filtration rate (eGFR) between groups 1 and 2. Furthermore, no significant differences were noted in the estimated blood loss, operative time, or warm ischemia time between the 2 groups. Although there was no significant difference in the rate of decrease in eGFR 4 weeks after RAPN between the 2 groups, the rate of decrease in eGFR 1 week after RAPN in group 1 was significantly lower than that in group 2. The choice of selective or total clamping was also identified as an independent predictor of a postoperative decrease in eGFR by > 10% at 1 week, but not 4 weeks, after RAPN.

CONCLUSIONS

A precise segmental clamping technique is feasible and safe for performing RAPN, resulting in an improved postoperative renal function, particularly early after surgery.

A Literature Review of Renal Surgical Anatomy and Surgical Strategies for Partial Nephrectomy

CONTEXT

A detailed understanding of renal surgical anatomy is necessary to optimize preoperative planning and operative technique and provide a basis for improved outcomes.

OBJECTIVE

To evaluate the literature regarding pertinent surgical anatomy of the kidney and related structures, nephrometry scoring systems, and current surgical strategies for partial nephrectomy (PN).

EVIDENCE ACQUISITION

A literature review was conducted.

EVIDENCE SYNTHESIS

Surgical renal anatomy fundamentally impacts PN surgery. The renal artery divides into anterior and posterior divisions, from which approximately five segmental terminal arteries originate. The renal veins are not terminal. Variations in the vascular and lymphatic channels are common; thus, concurrent lymphadenectomy is not routinely indicated during PN for cT1 renal masses in the setting of clinically negative lymph nodes. Renal-protocol contrast-enhanced computed tomography or magnetic resonance imaging is used for standard imaging. Anatomy-based nephrometry scoring systems allow standardized academic reporting of tumor characteristics and predict PN outcomes (complications, remnant function, possibly histology). Anatomy-based novel surgical approaches may reduce ischemic time during PN; these include early unclamping, segmental clamping, tumor-specific clamping (zero ischemia), and unclamped PN. Cancer cure after PN relies on complete resection, which can be achieved by thin margins. Post-PN renal function is impacted by kidney quality, remnant quantity, and ischemia type and duration.

CONCLUSIONS

Surgical renal anatomy underpins imaging, nephrometry scoring systems, and vascular control techniques that reduce global renal ischemia and may impact post-PN function. A contemporary ideal PN excises the tumor with a thin negative margin, delicately secures the tumor bed to maximize vascularized remnant parenchyma, and minimizes global ischemia to the renal remnant with minimal complications.

PATIENT SUMMARY

In this report we review renal surgical anatomy. Renal mass imaging allows detailed delineation of the anatomy and vasculature and permits nephrometry scoring, and thus precise, patient-specific surgical planning. Novel off-clamp techniques have been developed that may lead to improved outcomes.

Experience of laparoscopic partial nephrectomy using a kidney grasper in selective cases

OBJECTIVE

To evaluate the feasibility of regional cramp in laparoscopic partial nephrectomy, we performed partial nephrectomy using a kidney grasper that enabled the application of ischemia to a limited region of the kidney.

MATERIALS AND METHODS

The subjects were 5 renal cell carcinoma patients. The mean tumor diameter was 15 mm. There were 2 male and 3 female patients. A transperitoneal approach was used in all cases. Following the standard procedure of laparoscopic partial resection, the hilum of the kidney was confirmed and treated to prepare for rapidly applying clamping with forceps. Tumor resection and suture were then performed under partial warm ischemia using a kidney grasper.

RESULTS

Surgery could be completed in 4 patients using this method. In the remaining patient, control of bleeding was considered difficult during tumor resection after applying partial ischemia, and so the procedure was switched to renal artery clamping using bulldog forceps. In the 4 patients in whom a kidney grasper was used, the mean partial warm ischemia time was 23.6 minutes (range, 23-25 minutes), and the mean blood loss was 110 mL (range, 20-260 mL).

CONCLUSIONS

This procedure may be a useful option in ischemia for partial nephrectomy.

Comparison of selective parenchymal clamping to hilar clamping during robotic-assisted laparoscopic partial nephrectomy

OBJECTIVE

To compare perioperative outcomes after robotic-assisted laparoscopic partial nephrectomy (RALPN) with hilar clamping vs parenchymal clamping.

METHODS

A retrospective, single-institution review of the patients undergoing RALPN with hilar or parenchymal clamping was performed. Associations between perioperative factors and clinicopathologic outcomes were determined using the t test, Fisher's exact test, and multivariate linear regression.

RESULTS

In 51 patients undergoing RALPN, 36 (71%) and 15 (29%) were performed with hilar and parenchymal clamping, respectively. Median tumor diameter was 2.8 cm for both groups (range, 1.1-6.1; P = .93). Tumor complexity by nephrometry score was mild (69% vs 80%), moderate (29% vs 20%), and high (2% vs 0%) in the respective groups (P = .65). Operative time was significantly shorter in the parenchymal clamp group (median 245 vs 320 minutes; P <.0001). There was no difference in blood loss and need for transfusion. On multivariate analysis, hilar clamping (P <.01), higher body mass index (P = .01), and higher complexity tumors (P = .02) were significantly associated with longer operative times. The parenchymal clamp group had better preservation of immediate postoperative glomerular filtration rate (GFR) from baseline to postoperative day 2 (median ΔGFR 0 vs -18 mL/min/1.73 m(2), P = .02). These differences from baseline did not persist (median ΔGFR -6 vs -7 mL/min/1.73 m(2), P = .35) at a median follow-up of 6.6 months. Final pathology determination of malignancy (P = .51) and positive margin rates (P = .26) were similar in both groups.

CONCLUSION

Compared with hilar clamping, selective regional ischemia with the parenchymal clamp for mild-moderately complex tumors is feasible and safe during RALPN. Parenchymal clamping is associated with enhanced immediate preservation of GFR and shorter operative times.