The Impact of Laparoscopic Nephrectomy on Patient Outcome: A Community Perspective

Introduction

S ince the first laparoscopic nephrectomy was described by Clayman and colleagues ¹ in 1991, this approach has been adopted in most academic centers for extirpative renal surgery. ² Rapid uptake of this new technique was based on the clear benefits to individual patients as demonstrated in several large clinical series. ^{3 –5} Although initially recommended for benign disease or small renal masses, as urologists have become more familiar with the procedure and more adept at laparoscopic techniques, the contraindications to the laparoscopic approach have become more limited. ^6,7

Adoption of the technique, however, has not been universal, particularly outside major teaching hospitals because of the perceived difficulty of the technique, the lack of formal training for already established surgeons, and the paucity of clinical mentors/preceptors who can devote the time to teach the procedure. ^{8 –10} This has led some to suggest that laparoscopic surgery remain the domain of the specialist referral center. ¹¹

Geelong is a city of 200,000 people that is located approximately 75 km west of Melbourne, with a greater catchment population of 450,000 extending over 400 km from the South Australian border to the edge of municipal Melbourne (www.barwonhealth.org.au). The region is currently serviced by five urologists, with inpatient procedures being performed at either a single public hospital, Geelong Hospital Barwon Health (360 beds), or one of two private hospitals, St. John of God Hospital (163 beds) and Geelong Private Hospital (75 beds), depending on insurance status and medical needs.

In this report, we describe our experience in establishing a laparoscopic nephrectomy program and the benefits that have accrued to the community living around our regional center.

Patients and Methods

The first laparoscopic nephrectomy was attempted in Geelong in June of 2001. Patients who were eligible for a laparoscopic approach included those with renal tumors that were confined to the kidney with no preoperative evidence of extrarenal extension or renal vein involvement, or benign conditions (mainly nonfunctioning kidney) where extensive adhesions were not anticipated. We identified by casemix coding all nephrectomies that were performed in Geelong for the 10-year period around this date. For the purposes of this report, all nephrectomies that were performed in the study period before this initial attempt are considered “prelaparoscopic,” whereas all nephrectomies that were performed after this case regardless of whether they were performed open or laparoscopically are considered “postlaparoscopic.” Nephrectomies that were performed by pediatric surgeons and partial nephrectomies were excluded.

Case notes and operative reports were reviewed and demographic and operative details were extracted. Kidney pathology as well as tumor size and stage where applicable were culled from the original anatomic pathology reports. All blood transfusions as well as the number of units administered were determined by review of inpatient blood product prescriptions. Complications were recorded prospectively in the patient's discharge summary, but were retrospectively classified and graded according to the Clavien system. ¹² Statistical analysis was performed using SPSS 9.5 using parametric or nonparametric testing as appropriate.

Results

Over the 10-year period, a mean of 34 nephrectomies (range 25–55) were performed in Geelong annually. Of all nephrectomies, 99% were performed by one of six urologists or by a training registrar under their direct supervision. These surgeons differed considerably in their practice and training in laparoscopy. One surgeon, who retired in 1998, performed only open nephrectomies. Two established surgeons were self-taught laparoscopists, through a combination of wet- and dry-lab training and travel to centers of excellence. One established surgeon decided not to train in laparoscopy and referred suitable cases on, but performed open nephrectomy where indicated. One surgeon who commenced in 2003 had limited laparoscopic experience during his general surgical and urology registrar training but received formal training in upper tract laparoscopy during his postgraduate fellowship. One surgeon who commenced in 2006 had considerable experience in simple laparoscopy from his general surgical training (>100 laparoscopic cholecystectomies performed) and was essentially independent in laparoscopic nephrectomy at the end of his urology residency.

In the first 12 months after the initial procedure, 34% of all nephrectomies were attempted laparoscopically, which increased to 58% in the most current time period (Fig. 1). Concomitantly, the number of nephrectomies that were successfully completed laparoscopically has increased from 63% in the first 12 months to 97% currently.

OPEN IN VIEWER

FIG. 1.

Number of nephrectomies performed each year, by approach.

Selected demographic and operative details for the prelaparoscopic and postlaparoscopic cohorts are presented in Table 1. There were no significant differences in sex distribution, age, and insurance status between groups. Since the initial attempt at laparoscopic extirpation, 43% of nephrectomies/nephro-ureterectomies have been successfully completed laparoscopically, 6% were commenced laparoscopically but subsequently converted to open surgery, and 51% were performed as open surgery. Of the 13 patients who needed conversion, 7 were for bleeding, 4 were for failure to progress, 1 was for extensive intra-abdominal adhesions that precluded the establishment of an adequate pneumoperitoneum, and 1 was for a bowel injury that could not be repaired laparoscopically. Given that all but one laparoscopic nephrectomy was performed via a transperitoneal approach, significantly fewer retroperitoneal nephrectomies were performed in the postlaparoscopic era (P < 0.002). There was no significant difference in kidney side nor indication for nephrectomy between the two cohorts, with renal cell carcinoma (RCC) predominating.

The impact of laparoscopy on the surgical outcomes of each cohort is shown in Table 2. Since the introduction of laparoscopy, the mean procedure time for a nephrectomy has increased by exactly 1 hour, with the average operation now taking more than 200 minutes to perform (P < 0.001). In the same period, however, the mean length of stay has been reduced significantly, with an average saving of almost four inpatient days per procedure (P < 0.002). Additional benefits have included a trend toward a decrease in overall transfusion rates (P = 0.06), although the median number of units transfused remains unchanged, and a significant reduction in the incidence of both minor and major complications (P = 0.004 and 0.03, respectively).

The vast majority of patients who received transfusions had open surgery, a reflection both on the technique and the underlying pathology. Of the prelaparosocpic cohort, 31 of the 50 patients transfused had a nephrectomy for renal malignancy. Of these, seven had renal vein involvement, two needed inferior vena cava (IVC) exploration and thrombectomy, two sustained splenic injuries that necessitated removal, two underwent simultaneous vascular procedures, and one was returned to the operating room emergently with a reactive hemorrhage. Of the remainder, seven had surgery for an infected kidney, and two each had large sarcomas or traumatic renal injuries, all of which are associated with a more challenging procedure.

Of the 60 patients who received transfusions in the laparoscopic era, 19 underwent initial laparoscopic dissection, of whom 4 were converted to open surgery because of ongoing bleeding (1 had unexpected renal vein thrombus). This gives a “laparoscopic” transfusion rate of 19/90 (21%), likely reflecting the learning curve of the procedure that has been previously documented by other authors. ^13,14

Of the remaining 41 patients, 4 had surgery for infected kidneys and 2 for renal trauma. The remainder had surgery for RCC or transitional cell carcinoma (TC), of whom 12 had renal vain involvement, 2 underwent IVC thrombectomy, four needed splenectomy for iatrogenic trauma, 3 underwent simultaneous general surgical or vascular procedures, and 2 needed emergent return to the operating room for reactionary hemorrhage.

A breakdown of complications by era is shown in Table 3. There were four deaths in the prelaparoscopic group: Two from postoperative myocardial infarctions, one from generalized sepsis secondary to an iatrogenic colonic injury that was repaired at the time of initial surgery but subsequently leaked, and one from acute renal failure. There were three deaths in the postlaparoscopic era: Two from early postoperative myocardial infarcts and one intraoperative death from uncontrollable hemorrhage in an open nephrectomy for a large RCC that involved the renal vein with an extensive collateral circulation. As expected, the majority of major complications were related to underlying cardiovascular disease, respiratory compromise (particularly in those with open incisions), and renal insufficiency. Notably, the incidence of both major and minor complications has decreased significantly in the postlaparoscopic era, despite the fact that more than half of the cases in this time period were performed by an open approach.

The most common indication for nephrectomy in both the prelaparoscopic and postlaparoscopic era remains RCC, which accounts for approximately two-thirds of all cases. The increasing availability of urinary tract ultrasonography and abdominal cross-sectional imaging over the last two decades has led to a progressive stage migration in surgically treated RCC in contemporary series. ¹⁵ One possible explanation for the observed improvement in surgical outcomes in the postlaparoscopic era is a shift in the size and stage of tumors that were treated in Geelong during the period of study. We therefore examined the size and stage of tumors in patients who underwent a laparoscopic nephrectomy in the postlaparoscopic era (Table 4), as well as compared the size and stage distribution of tumors between the prelaparoscopic and postlaparoscopic cohorts (Table 5). As expected, we found that tumors in patients who were primarily offered a laparoscopic nephrectomy were significantly smaller, with two-thirds of patients having pT₁ disease (P < 0.002). In contrast, patients offered an open approach had a significantly higher proportion of pT₂ (P = 0.0098) and pT_3/4 (P = 0.049) cancers, although it is interesting to note that almost a quarter of patients offered laparoscopic nephrectomy had locally advanced disease. When we compared overall tumor size and stage distribution between those operated on in the prelaparoscopic vs the postlaparoscopic era, however, we found no significant differences.

Discussion

Open nephrectomy has been an established technique for the management of benign and malignant diseases of the kidney for more than 100 years. ^16,17 In uncomplicated cases, much of the morbidity of this procedure is related to the incision, particularly if a flank approach is used. Problems related to acute postoperative pain, limited diaphragmatic excursion and respiratory compromise, chronic wound pain and paresthesia, and an unsightly wound bulge because of poor healing are well recognized. ^18,19 By eliminating the need for a painful subcostal or flank incision, the laparoscopic approach improved dramatically rates of postoperative pain, analgesia requirements, length of hospital stay, and time for convalescence. ^3,20

Given the impressive advantages reported for laparoscopic renal surgery during the preceding decade, we decided to adopt the technique in 2001. Two surgeons who had limited previous laparoscopic experience learned the technique through a combination of skills laboratories and visits to centers of excellence. Although the first procedure was converted to open surgery, we persevered with the approach, eventually establishing an alternative to open nephrectomy in suitable patients. This ability was greatly enhanced by the addition of two surgeons who were facile in the technique in 2003 and 2006. In our first year, 11 nephrectomies were attempted laparoscopically, of which 7 were completed successfully. With increasing experience, the number of laparoscopically attempted nephrectomies steadily climbed, while the conversion rate continued to drop. We favored the transperitoneal approach, because this provided more familiar anatomic landmarks to guide surgery.

Despite our enthusiasm for laparoscopy, we remain conservative in our indications. Although we have no stringent criteria, we favor the approach for most benign conditions and small to median sized renal malignant masses that are confined to the kidney. This is reflected in our findings that more than 60% of higher stage tumors were removed via the open approach in the postlaparoscopic era.

The most striking change that has resulted from the adoption of the laparoscopic approach has been the significant reduction in morbidity experienced by the postlaparoscopic cohort. Although a significant number of open nephrectomies continued to be performed, overall patients enjoyed a significantly reduced length of stay, fewer blood transfusions, and a marked reduction in the rate of complications. Although the length of stay remains high in comparison to American series, this is a reflection of a number of factors, including the high proportion of open nephrectomies still being performed, which are associated with significantly increased lengths of in-hospital stay, the relatively high complication rate we report, as well as inherent differences within the Australian health care system whereby even patients who are undergoing uncomplicated surgeries for benign conditions experience a prolonged in-hospital stay. ^21,22

With the increasingly widespread availability of ultrasonography and CT, the detection of small renal masses has increased dramatically. ²³ We were concerned that the reason for the improved outcomes in the postlaparoscopic cohort was merely a reflection of the more favorable outcomes of these smaller tumors; however, when we compared the tumor characteristic of patients in both cohorts, they were almost identical. The strength of our series lies in our almost complete capture of clinical data of patients who were treated with nephrectomy in our catchment area. The three hospitals included in the study provide medical services to more than 95% of the population living in the catchment area, including initial treatment and follow-up, with complete datasets available for all patients identified. This enables us to evaluate accurately the benefits to the greater community, rather than just the individual patient, of the adoption of laparoscopic surgery.

The drive toward minimally invasive surgery is based on the desire to achieve equivalent results to gold standard operations while reducing morbidity and mortality. ²⁴ With increasing specialization of surgical skills and technical difficulty, this can be achieved, but rarely without prolonged periods of dedicated training. This has led some to advocate a “hub and spoke” model, whereby techniques that may be considered specialized are referred on to larger centers for surgery. While this model may operate efficiently in large urban centers or areas of high population density, it is not practical in countries such as Australia where patients must travel considerable distances for medical care.

When we commenced our program, laparoscopic nephrectomy was not widely available in Australia, and despite our community status, we were in the vanguard of centers to promote the procedure. This entailed not only an intense learning experience for our established open surgeons, but also for the theater staff and residents and nursing staff responsible for preoperative and postoperative care. As with any procedure where the advantages are obvious, however, the procedure became quickly established, both in the urologic community and within residency programs, so that at the end of their training, the majority of Australian residents are now expected to be independent in the procedure.

One criticism of our practice is that with four surgeons performing laparoscopic nephrectomy in our community, the number of nephrectomies performed by an individual surgeon is low. Although it is not known how many laparoscopic nephrectomies must be performed per anum to maintain competence, like many procedures, it is likely that surgeons performing a higher volume will have better outcomes. ²⁵ If we wish to impact further on community benefit, it may mean consolidating experience with both approaches to a limited number of surgeons.