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

Abstract

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.

Introduction

Kidney cancer ranks among the top 10 most prevalent cancers in the United States, ∼90% of which are renal cell carcinomas. Of the estimated 63,990 new cases in 2017, 14,400 people are estimated to die from the disease, making renal cell carcinoma the deadliest of genitourinary malignancies.¹ Extirpative therapy is currently the mainstay treatment for renal cell carcinoma. Traditional open surgery is widely utilized for the management of most renal tumors; however, laparoscopic surgery has demonstrated significant promise in improving several perioperative metrics associated with open renal surgery.²

In 1991, Clayman pioneered laparoscopic renal surgery by performing a radical nephrectomy utilizing an entirely minimally invasive approach.³ As our understanding of renal cell carcinoma has matured, there has been a paradigm shift in the management of small renal masses with strong emphasis now placed on nephron-sparing surgery.⁴ The direct association between diminished kidney function and cardiovascular disease emphasizes the importance of nephron-sparing surgery for renal masses smaller than 4 cm.^5,6 Concomitant with this change in surgical management is increased utilization of laparoscopic approaches to partial nephrectomy.

Increased use of cross-sectional imaging has been associated with a steep rise in the incidental detection of small renal masses. Tissue ablation techniques, such as radiofrequency ablation and cryoablation, have emerged as alternatives to nephron-sparing surgery and can be implemented through laparoscopic or percutaneous approaches.⁷

In this review, the current state of laparoscopic partial nephrectomy (LPN) is discussed with a specific focus on minimizing renal ischemia, functional, and oncologic outcomes. In addition, comparison is made primarily with the open surgical technique; however, we also discuss the evolution of minimally invasive renal surgery with the advent of the DaVinci surgical robot platform. In this context, emphasis is placed on the impact of robot-assisted nephron-sparing surgery on perioperative and oncologic outcomes relative to conventional laparoscopy.

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 “humans” and “English” on March 24, 2016. We identified 1022 potential articles.

The studies were initially screened for duplicates. Studies that focused on adult patients with kidney cancer, those that discussed functional and oncologic outcomes for LPN, and those that compared outcomes between LPN, open partial nephrectomy (OPN), or robot-assisted laparoscopic partial nephrectomy (RPN) were chosen. Studies that were not original investigations and those that did not evaluate the relevant outcomes and intervention were excluded from this review. Case reports and animal experimental studies were excluded. References of searched articles were also evaluated for potential inclusion (Fig. 1). Two independent reviewers completed this process and all disagreements were resolved by their consensus.

FIG. 1.

PRISMA flow diagram.

Evidence Synthesis

Minimizing renal ischemia

Clamping of the renal hilar vasculature is traditionally performed during partial nephrectomy to enhance observation and minimize bleeding during tumor resection. In this, however, lies risk for ischemia-reperfusion injury of remnant nephrons. Canine models and several clinical studies in the setting of a solitary kidney indicate 20 to 25 minutes to be the acceptable upper limit for warm ischemia time, although each additional minute of hilar clamping could confer significantly higher risk of acute kidney injury and chronic kidney disease.^8
–10 There are mixed results with regard to warm ischemia time in LPN vs OPN. Gill et al. showed a mean warm ischemia time of 30.7 minutes in the LPN compared with 20.1 minutes in the OPN cohort, a difference that was found to be statistically significant.² Conversely, Springer and associates demonstrated differing results, with a median warm ischemia time of 11.7 minutes in the LPN group and 14.4 minutes in the OPN group.¹¹ With experience, equivalent outcomes are obtained whether approached laparoscopically, robotically, or in an open manner.

Warm ischemia time remains a modifiable risk factor and efforts should be made to minimize potential impact on renal function. Several techniques have been described that reduce the effect of or decrease warm ischemia time. These include renal hypothermia, early unclamping, selective renal arterial clamping, parenchymal compression plus clamping, and off-clamp nephron-sparing surgery.

Renal hypothermia and cold ischemia

Renal hypothermia serves to cool the kidney in situ to 10 to 25°C with the intention of minimizing tissue-related ischemic injury associated with hilar clamping.¹² Gill et al. first reported their experience with laparoscopic renal hypothermia through placement of a large endoscopic bag around the kidney into which ice slush could be introduced. Nevertheless, although renal hypothermia is clinically feasible and relatively effective, it can be cumbersome to achieve as the introduction and evacuation of ice through a laparoscopic approach are technically difficult. As such, cold ischemia is not commonly utilized with minimally invasive partial nephrectomy (PN). To overcome these challenges, several variations to traditional renal hypothermia with ice slush have since been described and include renal artery cold saline perfusion and retrograde instillation of cold saline through ureteral catheters^13

–16 These studies have shown comparable renal function utilizing renal hypothermia when compared with experts' warm ischemia series, despite longer ischemia time in the renal hypothermia studies. Ramirez and colleagues. corroborated these findings in a recent study with ice slush cooling during RPN, having found a 12.9% improvement of estimated glomerular filtration rate (eGFR) postoperatively with cold ischemia among patients undergoing RPN with warm ischemia. However, there was no difference at 6-month follow-up.¹⁷ As such, renal hypothermia may provide the surgeon extended ischemia time, with similar long-term postoperative renal function as warm ischemia or shorter duration.

Hilar control/early unclamping

Early release techniques involve removal of vascular clamps after initial closure of the resection base with a running suture. Subsequent renorrhaphy is performed with the kidney perfused. In contrast, traditional hilar clamping encompasses completion of the renorrhaphy, including closure of the collecting system and parenchymal defect before the release of the arterial clamp.¹⁸ Multiple studies have shown decreased warm ischemia time (13.9 vs 31.1 minutes and 16.7 vs 22.3 minutes) when compared with traditional hilar clamping without an increase in postoperative complications.^19,20 Early unclamping may provide the additional benefit of decreasing risk of renal artery pseudoaneurysm. With an incidence of 1.7% to 2.6%, renal artery pseudoaneurysms, although rare, can lead to significant postoperative hemorrhage.²¹ In a study of 61 patients, Kondo et al. demonstrated a significantly decreased rate of renal artery pseudoaneurysm associated with early unclamping on multivariable analysis (hazard ratio 0.27; p = 0.01).²² The mechanism by which renal artery pseudoaneurysms form after partial nephrectomy remains unclear. One mechanism proposed is inadequate hemostasis within the resection bed. In this respect, early unclamping may reduce risk of pseudoaneurysm formation by providing the surgeon information regarding arterial bleeding from the resected bed before renorrhaphy is performed. An alternative theory for pseudoaneurysm formation involves the disruption of arterioles when suturing the renal sinus or parenchyma with larger laparoscopic needles.²²

Selective arterial ischemia

Clamping of arterial branches distal to the main renal artery permits selective ischemia of the tumor, while maintaining perfusion to the remnant normal renal parenchyma. Selective artery clamping, however, is technically demanding. Shao and colleagues were able to perform selective artery clamping on 81.6% of LPN cases; however, they were limited by variations of vascular segmentation, proximity of the tumor to the hilum, and bleeding from the parenchymal defect not easily controlled by segmental artery clamping.²³ The technical difficulty involved thus limits the utility of selective artery clamping and may lead to increased rates of perioperative blood transfusion (24% vs 6%).^23

–26 In addition, Komninos et al. demonstrated that selective arterial clamp techniques result in only transient improvement of renal function compared with clamping of the main renal artery clamp. Specifically, selective arterial ischemia resulted in a percentage change in eGFR of −2% compared with −8% in the main artery clamp cohort 3 months postoperatively, with no significant difference after 6 months.²⁷ There are no current studies that directly compare selective arterial ischemia between LPN and RPN cohorts. However, Martin and colleagues found no differences in operative blood loss, transfusion rates, or postoperative complications between selective artery clamping and total artery clamping in combined LPN and robotic cohorts.²⁸

Renal artery clamping

Clamping of both renal artery and vein during partial nephrectomy prevents venous backflow, enabling both better observation of the renal tumor margins and occlusion of secondary arteries. A commonly employed variation to this approach is selective clamping of the renal artery to enable retrograde flow of venous blood at low oxygen tension. Animal models reveal benefit to selective arterial clamping. Studies performed in the porcine model have demonstrated decreased serum creatinine on postoperative days 1 and 3 when compared with complete hilar clamping. Significantly less reduction in glomerular volume density was also observed with selective arterial clamping in the rat model.^29,30 Similar results have been observed in human subjects undergoing selective arterial clamping.³¹ A recent study by Funahashi et al. examined effective renal plasma flow through Tc-99m-MAG3 scintigraphy preoperatively and at 1 week and 6 months postoperatively for 58 patients. Although they observed a decrease in Tc-99m-MAG3 uptake of the operated kidney at 1 week postoperatively that correlated with duration of warm ischemia, the artery-only clamp group had significantly less decrease when ischemia time was limited to 25 minutes (88.1% vs 102.5%, p = 0.001).³²

Parenchymal compression

Parenchymal compression has been used to provide regional ischemia and avoid vascular occlusion during partial nephrectomy.³³ Gill and colleagues first proposed this technique utilizing a double loop tourniquet. In a subsequent report, Simon et al. reported the use of a novel laparoscopic parenchymal clamp that enabled similar regional tissue compression.^34,35 Tumors most amenable to this technique are those situated in polar locations or those that are exophytic and situated along the lateral contour of the kidney, identical to the ideal location for lesions that can be managed by radiofrequency ablation and cryoablation. Parenchymal compression in 20 patients undergoing RPN resulted in no significant difference in preoperative and immediate postoperative glomerular filtration rate (86 mL/min/1.73 m(²) vs 78 mL/min/1.73 m², p = 0.33) or 6-month GFRs (86 mL/min/1.73 m(²) vs 78 mL/min/1.73 m², p = 0.54).³⁶ A similar report on perioperative outcomes after RPN comparing hilar clamping and parenchymal clamping in 51 patients found parenchymal clamping to be associated with improved immediate preservation of GFR (ΔGFR 0 vs −18 mL/min/1.73 m², p = 0.02) and shorter median operative times (245 vs 320 p < 0.0001).³⁷

Off-clamp technique

Off-clamp partial nephrectomy carries the theoretical benefit of avoiding ischemia-related nephron injury during tumor resection. The trade-off, however, is an increased risk of intraoperative blood loss.^38

–42 Initial functional assessment of off-clamp surgery in the setting of laparoscopy was carried out by Guillonneau et al., who compared 12 patients undergoing off-clamp LPN vs 16 patients undergoing traditional LPN (Table 3).³⁸ Increased mean operative time (179.1 minutes vs 121.5 minutes, p = 0.004) and blood loss (708.3 mL vs 270.3 mL, p = 0.014) was demonstrated with off-clamp surgery, however, the study also demonstrated a lower increase in serum creatinine (0.09 vs 0.2, p = 0.05) was also observed, attesting to the perioperative functional benefit derived from the off-clamp technique. Results surrounding long-term functional benefit of off-clamp surgery remain controversial. The solitary kidney model has demonstrated that off-clamp surgery has a <10% decrease in late GFR when compared with the clamping group (60.9% vs 17.7%, p = 0.002).⁴³ As such, it would follow that off-clamp surgery would maximize renal functional preservation. Studies in the setting of elective PN have also shown improved eGFR after off-clamp surgery vs on-clamp surgery (5.8% vs 11.4%, p = 0.046).⁴¹ However, more extended longitudinal follow-up of this cohort revealed no significant difference in eGFR or the rate of chronic kidney disease between the on-clamp and off-clamp cohorts with 5 years follow-up⁴²; instead, recovery of renal function was observed among those who underwent hilar clamping. The suggested absence of long-term benefit implies that the physical conservation of nephron units may be a more critical determinant of renal function.

Table 3.

Tumor Characteristics of Off Clamp and On Clamp Comparative and Noncomparative Series

	Tumor dimensions (cm)		Tumor staging (histopathologic)			Tumor location
Guillonneau and colleagues³⁸	Off clamp (12)	On clamp (16)	pT1		17	Off clamp (12)		On clamp (16)
	2.0 ± 0.56	2.52 ± 0.88				Upper	1	6
			pT3a		1	Lower	10	3
						Interpolar	1	6
Rais-Bahrami et al.³⁹	Off clamp (126)	On clamp (264)		Off clamp (126)	On clamp (264)		Off clamp (126)	On clamp (264)
			T1a	87 (79.1)	178 (87.7)
	2.4 ± 1.0	4.6 ± 2.2	T1b	8 (57.1)	37 (77.1)	Upper pole	42	101
			T2	2 (100)	10 (76.9)	Interpolar	38	84
	Off clamp (101)		T1b/T2	10 (62.5)	47 (77)	Lower pole	46	78
Simone et al.⁴⁰						Off clamp (101)
	2.4 (1.5–4)		Benign tumors		30	Upper pole	56
			pT1a clear RCC		58	Lower pole	40
			pT1a type 1 papillary RCC		8
			pT1a chromophobe RCC		3	Interpolar	5
	Off clamp (150)	On clamp (289)	pT1b clear RCC		2
George et al.⁴¹			n/a				Off clamp (150)	On clamp (289)
	2.7 (0.4–9)	3.3 (0.5–13.5)				Upper pole	42	89
						Interpolar	33	61
						Lower pole	43	70
						Unavailable	32	69
Shah et al.⁴²	Off clamp (106)	On clamp (209)	n/a				Off clamp (106)	On clamp (209)
	3.0 (1.7)	3.4 (1.7)				Upper	34 (33)	76 (37)
						Interpolar	31 (31)	67 (33)
						Lower	37 (36)	62 (30)

RCC = renal cell carcinoma.

Advancements in conventional laparoscopy have led to the development of off-clamp laparoendoscopic single-site partial nephrectomy. Schips and colleagues demonstrated that off-clamp laparoendoscopic single-site surgery for single, small, exophytic, cortical renal masses is a safe and feasible procedure providing no significant variation in serum creatinine and estimated glomerular filtration rate between preoperative and follow-up values. Additionally, the study demonstrated high levels of patient cosmetic satisfaction.⁴⁴

Functional outcomes

A fundamental goal of LPN is the preservation of renal function. Numerous studies have compared the functional outcomes of the laparoscopic approach with traditional open surgery. The largest of series comparing perioperative outcomes was performed by Gill et al., who demonstrated among 1800 patients undergoing PN a significantly lower operative time, decreased intraoperative blood loss, and a shorter hospital stay associated with LPN.² However, LPN was associated with increased postoperative morbidity, including increased risk of conversion to radical nephrectomy when compared with OPN. Early functional and oncologic outcomes were equivalent between both techniques. Long-term studies evaluating renal functional and cancer control echo these findings and show no significant difference in postoperative eGFR between LPN and OPN at 5 and 10 years follow-up.^11,45,46 Nevertheless, LPN requires technical expertise to ensure optimal perioperative outcomes.

There are differing reported complication rates after LPN and OPN. Marszalek and colleagues observed that although intraoperative complications were more common in the LPN group (p = 0.05), no differences in frequency of postoperative complications, such as urinoma or renal hemorrhage (p = 0.8), were appreciated compared with OPN.⁴⁵ Gill and colleagues, however, reported a postoperative complication rate after LPN that was 1.66 times higher than that after OPN (p < 0.0001).⁴⁷ In a series by Springer et al., a median complication rate of 4.1% was seen in the LPN arm compared with 5.9% after OPN (p = 0.04). Notably, urine leakage occurred in three patients (1.7%) after LPN and in five patients (2.9%) after OPN. In addition, two patients (1.2%) required postoperative blood transfusions in the LPN group compared with 4 (2.4%) in the OPN group (p = 0.03).¹¹

Oncologic outcomes

Long-term oncologic outcomes of LPN have been shown to be comparable with OPN in several reports (Table 1). Most recently, Springer and colleagues observed that the 5-year cancer-specific and overall survival of LPN and OPN to have been 91% vs 88% and 94% vs 91%, respectively.¹¹ These results were corroborated by Marszalek et al. who reported an overall survival of 96% vs 85% (p = 0.1) in patients undergoing LPN vs OPN, respectively.⁴⁵

Table 1.

Long Term Oncologic Outcomes Analyzing Laparoscopic and Open Partial Nephrectomy

	Approach	Cohort size	Median follow-up (month)	Mean tumor size (cm)	Pathologic tumor stage	Positive margins (rate)	Overall survival	Cancer-specific survival	Recurrence-free survival
Gill et al.²	LPN	514	14.4	2.7	n/a	2.85%	n/a	99.3% (3 years)	97.7% (3 years)
Gill et al.²	OPN	676	33.6	3.5	n/a	1.26%	n/a	99.2% (3 years)	96.4% (3 years)
Marszalek et al.⁴⁵	LPN	81	43.2 (mean)	2.8	pT1 only: 100	4.0%	96% (5 years)	n/a	96.2% (5 years)
Marszalek et al.⁴⁵	OPN	66	42 (mean)	2.9	pT1 only: 100	2.0%	85% (5 years)	n/a	94.5% (5 years)
Springer and colleagues¹¹	LPN	170	45.7	2.8	pT1a: 143pT1b: 27	1.2%	94% (5 years)	91% (5 years)	n/a
Springer and colleagues¹¹	OPN	170	45.7	2.9	pT1a: 136pT1b: 34	1.7%	92% (5 years)	88% (5 years)	n/a
Lane et al.⁴⁶	LPN	625	79.2	2.6	pT1a: 395pT1b: 35pT2 or higher: 31	1.0%	78% (10 years)	n/a	96.9% (10 years)
Lane et al.⁴⁶	OPN	916	93.6	3.5	pT1a: 499pT1b: 192pT2 or higher: 51	0.3%	72% (10 years)	n/a	92.3% (10 years)

LPN = laparoscopic partial nephrectomy; n/a = not available; OPN = open partial nephrectomy; RPN = robot-assisted laparoscopic partial nephrectomy.

Similar cancer control has also been demonstrated by several noncomparative studies (Table 2). A review of 800 patients undergoing LPN by Gill and colleagues observed an overall survival and cancer-specific survival of 90% and 99%, respectively, resulting in significant congruence with another large series evaluating outcomes after RPN.^47,52 Mukkamala and colleagues reviewed the oncologic outcomes associated with minimally invasive PN, encompassing LPN, RPN, and hand assisted, and found an overall survival of 95.6%, 89.1%, and 70.7% at 2, 5, and 10 years, respectively.⁵³ In summary, LPN and OPN oncologic outcomes are similar, and the surgical approach does not influence overall survival, nor is it associated with recurrence.

Table 2.

Noncomparative Oncologic Outcomes of Laparoscopic Partial Nephrectomy

	Approach	Cohort size	Median follow-up (month)	Mean tumor size (cm)	Positive margins (rate)	Overall survival	Cancer-specific survival	Recurrence-free survival
Moinzadeh and colleagues⁷¹	LPN	100	42	3.1	1.5%	86% (3 years)	100% (3 years)	100% (3 years)
Lane et al.⁵⁴	LPN	58	68.4	2.9	2.7%	86% (5 years)	100% (5 years)	97.3% (5 years)
Gill et al.⁴⁷	LPN	800	36	3.1	1.0%	90% (5 years)	99% (5 years)	97.8% (5 years)
Khalifeh and colleagues⁵²	RPN	134	n/a	3.0	1.0%	90.2% (5 years)	99% (5 years)	n/a
Mukkamala et al.⁵³	LPN, RPN, hand assisted	417	39.6	2.9	5.5%	70.7% (10 years)	n/a	88.3% (10 years)

There lies an inherent risk of tumor violation during partial nephrectomy. As such, positive surgical margin (PSM) remains a real concern. The risk of PSM during LPN is estimated to range between 1.0% and 7.8%.^2,54
–56

Comparisons of LPN and OPN yield mixed results with respect to incidence of PSM. Although many studies demonstrate no significant difference in PSM rate, a large series by Springer et al. observed lower PSM rate after LPN (1.2 vs 1.7, p = 0.09).^45,46 Interestingly, a recent study evaluating RPN shows that the PSM rate to be even lower than with LPN (3.2% vs 9.7% p < 0.001)⁵¹; however, these data contradict previous findings in which there were no statistical difference in PSMs between RPN and LPN.^48
–50,57 Although debate remains regarding the significance of PSM, surgeons must take steps to ensure negative surgical margins, as this constitutes the trifecta of PN.⁵⁸ Achievement of negative surgical margins does not necessitate wide excisional margins or intraoperative frozen sections. A multicenter, retrospective comparative analysis of 982 patients undergoing traditional OPN with extensive margins and 537 patients undergoing simple enucleation showed no significant difference in progression-free survival and cancer-specific survival.⁵⁹ With regard to intraoperative frozen sections, Gordetsky et al. recently recommended against the use of frozen section because of the relatively high false negative rate; indeed the sensitivity of frozen section for final PSM on the tumor specimen has been reported to be as low as 30%.^60,61 Intraoperative ultrasonography is a valuable tool during LPN that aids in tumor identification and guidance of tumor extripation.⁶² Ultrasound probes have been more recently developed for the robotic platform as well, with comparable perioperative outcomes and surgical margin rates as the laparoscopic ultrasound probe. One purported advantage of the robotic ultrasound probe is the ability for the surgeon to control the probe, which is in contrast to laparoscopic ultrasound probes, which is generally controlled by the bedside assistant.⁶³

Robotic outcomes

RPN is a popular approach to treat small renal masses, affording the surgeon three-dimensional optics and articulating wristed instrument motion. These advancements have lessened the technical challenges posed by LPN and have shortened the surgical learning curve. For instance, the sliding clip technique has become the most common technique during the renorrhaphy for robotic partial nephrectomy, demonstrating significant improvements over operative and warm ischemia time. This technique involves a pretied knot at the end of a 15 cm 0 or 1 suture. In addition, a LapraTv is applied above the knot, and a Weck Hem-o-lock above that. During the final throw of the renorrhaphy, a second Hem-o-lock is applied by the assistant, and the robotic needle driver is used to slide the Hem-o-lock clip over the suture to tighten the suture. A final LapraTv is used to secure the second Hem-o-lock.⁷²

The advent of the robotic platform for minimally invasive partial nephrectomy has significantly reduced use of the laparoscopic approach.⁶⁴ It has been further demonstrated that the easier learning curve associated with RPN may have encouraged increased utilization of nephron-sparing surgery in the management of renal mass.⁶⁵ Nevertheless, the data do not support superiority of RPN over LPN from a perioperative outcomes standpoint. Two recent meta-analyses found RPN to be a feasible and safe alternative to laparoscopy with decreased warm ischemia time and no difference in operative, estimated blood loss, hospital stay, or complications.^48,66 However, these conflict with a more recent review, showing RPN with significantly lower rate of conversion, shorter warm ischemia time, smaller change of eGFR, and shorter length of stay.⁴⁹ Still, these studies are qualified by significant heterogeneity in surgeon experience and intraoperative technique, limited follow-up time, lack of prospective, randomized comparison, and increased cost associated with RPN.^48

–51

Comparison Between Techniques

Open, laparoscopic, and robotic approaches each have distinct advantages over the others in certain clinical scenarios. As mentioned previously, achieving renal hypothermia through the laparoscopic approach is often cumbersome, and results in similar long-term postoperative renal function as warm ischemia.¹⁷ Open surgery circumvents these challenges with direct application of the ice slush. Also, patients with chronic renal insufficiency are best suited with the robotic approach. Several studies describe warm ischemia times that are shorter by 2.7 to 4.3 minutes in patients undergoing RPN.^48,49,66 Laparoscopic and open surgeries are amenable to patients with obesity, with one study showing no difference in operative time, warm ischemic time, estimated blood loss, hospital stay, or complications. Other studies have demonstrated no significant difference in obese patients undergoing LPN compared with nonobese patients undergoing LPN.^67,68 Lastly, hilar tumors are amenable to laparoscopy. In the hands of an experienced laparoscopic surgeon, LPN can be utilized for hilar tumors with preservation of perioperative outcomes and no significant difference in functional and oncologic outcomes.^69,70

The main limitation of this review is that the majority of the included studies were retrospective and nonrandomized. However, overcoming this limitation may not be realistic, and would necessitate prospective randomized studies comparing LPN with OPN and RPN. In addition, this study could not take into account differences of surgical technique that may exist among different institutions.

Conclusion

Since its first case report in 1991, laparoscopic renal surgery has undergone a multitude of advancements with numerous reported variations in technique. LPN affords equivalent ischemia time, functional outcomes, oncologic outcomes, and equivalent complication rates compared with OPN. Future advances in laparoscopic technique and advancements in robotic technology offer potential to improve surgical and patient outcomes.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

Abbreviations Used

References

“Cancer Stat Facts: Kidney and Renal Pelvis Cancer.” Surveillance, Epidemiology, and End Results Program, Surveillance Research Program, seer.cancer.gov/statfacts/html/kidrp.html. April 22, 2017.

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