Laparoscopic vs open partial nephrectomy in consecutive patients: the Cornell experience

Authors


Michael Palese, The Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1272, New York, NY, 10029, USA.
e-mail: Michael.Palese@MountSinai.org

Abstract

OBJECTIVE

To compare a contemporary series of laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) at one institution, to evaluate the size and types of tumour in each group and the early outcome after each procedure, as LPN is replacing open radical nephrectomy as the standard of care for uncomplicated renal tumours but partial nephrectomy remains significantly more difficult laparoscopically, especially if the goal is to duplicate the open surgical technique.

PATIENTS AND METHODS

We retrospectively analysed the records of all patients who underwent partial nephrectomy at our institution from January 2000 to April 2004, identifying 66 who had LPN and compared them with 59 who had OPN (mean age at LPN and OPN, 62.1 and 64.2 years, respectively; 70% men in each group). Variables analysed included operative time, blood loss, creatinine levels before and after partial nephrectomy, time to resuming clear liquids and regular diet, length of stay, tumour size, tumour pathological type and complications. Groups were compared using Student's t-test, with P < 0.05 taken to indicate significance.

RESULTS

Of those having LPN, 59% had right-sided tumours, vs 53% in the OPN group; the respective mean tumour size was 2.2 and 3.4 cm, the mean operative duration 144 and 239 min (both P < 0.001), and the mean estimated blood loss 236 and 363 mL (P = 0.09). Seven patients in the OPN group had obligatory partial nephrectomy for either a solitary kidney (two) or azotaemia (five). No patient in the LPN group required an obligatory partial nephrectomy. Serum creatinine levels were measured before and 1 and 2 days after surgery, and were 88, 88 and 97 µmol/L for the LPN group, and 97, 106 and 106 µmol/L for the OPN group. Clear fluids were started a mean of 41 h after surgery, a regular diet resumed 76 h after and discharge was 129 h after surgery in the OPN group; the respective values for the LPN group were 24 h (P = 0.01), 49 h (P = 0.2) and 82 h (P < 0.001). Complications were similar in both groups but the pathological subtypes differed.

CONCLUSIONS

LPN offers early functional advantages over OPN in terms of earlier resumption of diet and slightly earlier discharge. However, the two groups of patients were clearly not evenly matched for size nor pathological subtypes, with larger, malignant subtypes more predominant in the OPN group. These results suggest that while LPN is a safe, effective treatment for small renal tumours, obligatory partial nephrectomy or large tumours continue to be performed using open techniques with good results.

Abbreviations
(L)(O)PN

(laparoscopic) (open) partial nephrectomy.

INTRODUCTION

Laparoscopic radical nephrectomy is replacing open radical nephrectomy as the standard of care for uncomplicated renal tumours. Partial nephrectomy remains a significantly more difficult procedure laparoscopically, especially if the goal is to duplicate open surgical technique. The first laparoscopic partial nephrectomy (LPN) was reported in 1991 and the initial experience was positive [1–3]. In their initial experience with six cases, Winfield et al.[4] completed four LPNs; while their operative duration was considerably longer, convalescence was considerably shorter than the historical experience with open partial nephrectomy (OPN). This initial series provoked tremendous interest in LPN.

The many debates comparing the merits of laparoscopic radical nephrectomy to OPN in situations of elective partial nephrectomy suggest that many surgeons avoid LPN because the procedure is difficult. However, advances in surgical sealants, haemostatic agents and laparoscopic vascular clamps have greatly simplified LPN. Furthermore, the hand-assisted devices give the operating surgeon greater control and tactile feedback, which may make urologists more comfortable when performing LPN.

We reported our initial experience with hand-assisted laparoscopic nephrectomy [5]; our initial experience with 11 patients required only one conversion to the open technique. Only four of the 11 tumours were malignant and there were no positive margins. A recent report of 30 consecutive hand-assisted LPNs showed the success of this procedure (no open conversions) and the safety (no recurrences, few minor complications) of this technique [6].

We designed our study as a retrospective review of all patients who had LPN by two surgeons (J.J.D., R.E.S.) over a 4-year period, comparing these patients with all those having OPN by one surgeon (E.D.V.) at our institution. Specifically, we assessed our initial practice patterns for selecting which patients had OPN or LPN, and were also interested in detecting any differences in the populations, and assessed early complication rates, especially after recent evidence suggesting that a ≈ 30% complication rate in LPN [7].

PATIENTS AND METHODS

We retrospectively analysed the records of all patients who had partial nephrectomies at our institution from January 2000 to April 2004, identifying 66 patients who had LPN and 59 consecutive patients who had OPN (mean age at LPN and OPN, 62.1 and 64.2 years, respectively; 70% men in each group). Hand-assisted LPN was as previously described [5]; during the most recent 34 LPNs we used hilar clamping half the time, at the discretion of the operating surgeon. Intraoperative frozen sections were analysed routinely during this period, and re-resection for margin status was used as needed. Haemostasis was achieved with a combination of suturing large vessels with 3/0 and 4/0 braided absorbable sutures, argon-beam coagulation and adjunctive haemostatic agents, including Gelfoam (Pfizer, New York, NY, USA), Surgicel (Johnson and Johnson, New Brunswick, NJ, USA) Tisseal (Baxer International, Lakewood, IL, USA) and Bioglue (Cryolife Inc., Kennesaw, GA, USA).

Patients were included based on their surgical status; all were included regardless of tumour size or obligatory vs elective surgery. Data were taken from a prospectively gathered database for the LPN group and from a retrospectively created database for the OPN group. Data analysed included demographic information, radiographic tumour size estimates, operative duration, estimated blood loss, creatinine levels before and after partial nephrectomy, analgesic requirements, complications and pathological subtypes. We also assessed whether the partial nephrectomy was elective or obligatory, from the preoperative notes and clinical characteristics .

The two groups were compared using Student's t-test for continuous variables and the chi-square test for categorical variables, with P < 0.05 taken to indicate statistical significance.

RESULTS

The demographic and laboratory data are shown in Table 1; 46 men had LPN and 41 OPN; 59% of patients in the LPN group had right-sided tumours, vs 53% in the OPN group. The mean tumour size for the OPN group was 3.4 cm compared to 2.2 cm for the LPN group (P < 0.001). Serum creatinine levels were not significantly different between the groups before surgery, nor did they increase significantly afterward. Blood loss was less in the LPN group, but the difference was not significant. Seven patients in the OPN group had obligatory partial nephrectomy for either a solitary kidney (two) or azotaemia (five). No patient in the LPN group required an obligatory partial nephrectomy.

Table 1.  The demographics and laboratory data for the LPN and OPN groups, and the pathological subtype of renal cancer
VariableOPNLPNP
N 59 66 
Mean (sd):
Age, years 64.2 (12.3) 62.1 (11.7) 
Operative duration, min239 (57.8)144 (38.4)<0.001
Creatinine, µmol/L
before partial nephrectomy 97 (62) 88 (18) 
1 day after106 (67) 88 (18) 
2 days after106 (68) 97 (27) 
Estimated blood loss, mL363 (241)236 (382)0.09
Pathological subtype, n
Clear cell carcinoma 30 18 
Papillary carcinoma  5 15 
Chromophobe carcinoma  4  2 
Unclassified  1  3 
Lymphoma  0  2 
Oncocytoma 10  4 
Benign solid/cystic lesions  5 10 
Angiomyolipoma  3  5 

In the LPN group three procedures were done via the standard laparoscopic approach with one conversion to hand-assisted laparoscopy, and 63 were via a hand-assisted approach from the beginning. Hilar clamping was used half the time, with a mean (range) warm ischaemia time of 18.2 (7–60) min. The largest tumour treated laparoscopically was 4.5 cm. There was one positive margin on final pathology. In the OPN group, hilar clamping was used in 45 of the 59 patients; the mean cold ischaemia time was 32.4 (25–40) min. The largest tumour treated was 13 cm, during an obligatory partial nephrectomy .

Fifty-two patients required epidural patient-controlled analgesia after surgery and three further patients had i.v. patient-controlled analgesia in the OPN group. In the LPN group only 18 patients required i.v. patient-controlled analgesia and the remainder were managed with toradol i.v. and oral narcotics.

After OPN, clear fluids were started at a mean of 41 h, a regular diet resumed at 76 h and discharge was at 129 h; the respective values in the LPN group were 24 h (P = 0.01), 49 h (P = 0.2) and 82 h (P < 0.001).

In the LPN group, one splenic injury was managed laparoscopically, one patient required a delayed laparotomy for bleeding, two had ileus (>4 days without tolerating oral intake) and two required Jackson-Pratt drains for 5 days for a prolonged urine leak, one of whom was stented with a JJ stent, with prompt resolution of symptoms. The overall complication rate was 9%.

In the OPN group, five patients had ileus and four developed UTIs; one developed pneumonia and one had a prolonged hospitalization complicated by a postoperative myocardial infarction and a urine leak, and required a JJ stent. Notably, this patient was a diabetic with chronic renal insufficiency and a tumour in a solitary kidney. The overall complication rate was 19%.

The distribution of pathological subtypes is also shown in Table 1. The most commonly diagnosed tumours in the OPN group were clear cell carcinomas (30), 10 oncocytomas, five papillary tumours, and five benign cysts. One metanephric adenoma was resected in this group. In the LPN group, clear cell carcinoma was again the most common type diagnosed, followed by papillary carcinomas, benign solid or cystic lesions and angiomyolipomas. Seven patients in the LPN group had no pathology reports available.

DISCUSSION

Partial nephrectomy is considered the standard of care for renal masses of <4 cm diameter in patients with solitary kidneys, nonfunctional contralateral kidneys or with azotaemia [8]. With further technical refinements, nephron-sparing surgery is now applied to elective lesions of ≤ 4 cm with a normal contralateral kidney and normal renal function [9–14].

Since the initial description of laparoscopic radical nephrectomy its popularity has increased [1]. This procedure has been widely used in patients, especially poor operative candidates with smaller tumours [15]. A recent report addressed the comparison of elective OPN and LPN at one institution [16]; these authors found that the laparoscopic approach led to a faster recovery and shorter hospital stay, but long-term renal function was better in the OPN group.

Several recent reports established the safety and efficacy of LPN for small renal tumours [2,6,7,16–18]. If there is involvement of the collecting system that requires repair, this can also be done during LPN [19]; such procedures were successfully completed but took longer, had longer warm ischaemia times, greater blood loss and the patients had a longer hospital stay than patients not requiring calyceal repair [19]. Renal vascular clamping decreases operative times and blood loss during LPN [20]. These advances and experience with this technique have combined to popularize the technique of LPN. Despite the interest, the ‘gold standard’ of nephron-sparing surgery remains OPN [14]. Long-term follow-up data support the widespread use of nephron-sparing surgery in both obligatory and elective situations.

The present study sought to identify our practice pattern during the emergence of LPN at a tertiary-care institution, evaluating the safety and efficacy of LPN vs the standard OPN. We were also interested in determining any differences in pathological outcome associated with either procedure. The patients treated by OPN had a mean stay of ≈ 5 days, resumed clear liquids 2 days after surgery and started eating solid food 3 days after. Patients treated by LPN resumed clear liquids 1 day after surgery, a regular diet the next day and most were discharged home 3 days after LPN. The differences for resumption of fluid intake and discharge were significant. Creatinine levels were not significantly higher in either group after surgery. These data support the general idea that laparoscopic surgery is less morbid and allows for a faster recovery than open surgery, and support previously published data [16].

Despite these advantages, the groups were not equivalent; the LPN was significantly faster than OPN and the blood loss less, but the tumours were significantly larger in the OPN group. The OPN group also had a greater risk of having clear cell carcinoma. These factors may account for the longer surgery and greater blood loss, by increasing the degree of difficulty of the procedure. Importantly, the primary renal tumours of higher malignant potential (clear cell carcinoma, papillary, chromophobe and unclassified) were slightly over-represented in the OPN than in the LPN group (Table 1). These data are consistent with the size difference, as larger tumours in general are more likely to be classified as carcinoma. Furthermore, seven patients in the OPN group had obligatory nephron-sparing surgery for a solitary kidney or azotaemia, compared to none in the LPN group. All of these data suggest that the OPN group represented higher-risk tumours in a higher-risk population.

As this group represents our emerging experience with a difficult new procedure, these comparisons are not surprising. Initially, only small peripheral tumours were attempted laparoscopically. Tumours of >4 cm that had a suggestion of extension into the parenchyma were treated by open surgery. As we gained experience with the LPN technique and were convinced of its safety, we began to apply this technique to more centrally located lesions.

The Cleveland Clinic experience comparing LPN and OPN was also recently reported [21]; their data were similar, in that tumours in the open group were larger and more patients in the open group had obligatory partial nephrectomies. Blood loss was greater and the hospital stay longer in their open group. All of these differences were significant. Furthermore, the open group in their series had more clear cell carcinomas, while the laparoscopic group had more benign tumours. All of these data are consistent with our experience.

LPN represents a viable option for small renal masses in general; for those patients requiring obligatory partial nephrectomy, or those with large tumours involving the collecting system, we continue to offer OPN, but as we gain additional experience with this challenging technique, we are expanding the indications for LPN and have begun to treat centrally located tumours with LPN. Clamping the renal artery is left to the discretion of the operating surgeon for both OPN and LPN, but is recommended for larger, centrally located tumours. We consider that laparoscopic radical nephrectomy is not a substitute for OPN. When partial nephrectomy is indicated a partial nephrectomy, whether OPN or LPN, should be performed.

In conclusion, LPN offers significantly shorter convalescence and less morbidity, with excellent functional outcomes compared to OPN. Both techniques are viable options for treating small renal masses in elective nephron-sparing surgery. However, for obligatory partial nephrectomy or large centrally located tumours, we recommend OPN be used in all but the most experienced centres.

CONFLICT OF INTEREST

None declared.

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