EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Laparoscopic living-donor nephrectomy is now widely used because of its many beneficial features. Currently, there are 2 major techniques: the laparoscopic intraperitoneal approach and the retroperitoneoscopic approach. There is no evidence to support one particular approach over another. Therefore, in this study, we conducted a systematic literature review with the aim of defining which technique is superior.

Materials and Methods: The Embase, PubMed, and Cochrane literature databases were searched for English language articles published between January 1994 and January 2013 using the terms “laparoscopic donor nephrectomy,” “retroperitoneoscopic donor nephrectomy,” and “live donor nephrectomy.” A meta-analysis was undertaken, and I2 statistical analyses were used to describe the percentage of variation across studies due to heterogeneity rather than chance.

Results: With the use of our selection criteria, 55 papers on the laparoscopic intraperitoneal approach and 6 papers on the retroperitoneoscopic approach were included in this study. We found significantly lower transfusion rate, fewer patients with delayed graft functions, less vessel injuries, and less conversion to open surgical procedure with the retroperitoneoscopic approach than with the laparoscopic intraperitoneal approach.

Conclusions: From this review, a high degree of study heterogeneity was identified, suggesting an urgent need for consistency in reporting laparoscopic living-donor nephrectomy. Results of the meta-analyses may define a better technique for the future. The retroperitoneoscopic approach may be better than the laparoscopic intraperitoneal approach with fewer complications and fewer patients with delayed graft function. Further study of laparoscopic living-donor nephrectomy is recommended to define a standard and thus to minimize the surgical morbidities.

Key words : Laparoscopic donor nephrectomy, Living kidney donor, Retroperitoneoscopic donor nephrectomy

Laparoscopic living-donor nephrectomy has been widely accepted as a safe procedure with multiple benefits, and kidney graft function has been shown to be comparable to that shown in patients who undergo open donor nephrectomy.^1-6 Currently, there are 2 major techniques for laparoscopic donor nephrectomy: the laparoscopic intraperitoneal approach (LIA) and the retroperitoneoscopic approach (RA). In addition, a hand-assisted technique has also been applied to each of these 2 approaches. There is no evidence supporting one particular approach over the other. In the era of open donor nephrectomy, a retroperitoneal approach using a flank incision is the usual approach,^7-9 as the kidney is located in the retroperitoneal space, and less frequently as an intraperitoneal approach with a midline or subcostal incision. Therefore, the aim of this study was to conduct a literature review on the techniques used for laparoscopic living-donor nephrectomy and to perform a meta-analysis to compare the outcomes and complications associated with LIA versus RA. The hand-assisted technique was not included in our review.

Materials and Methods

The Embase, PubMed, and Cochrane literature databases were searched for English language articles published between January 1994 and January 2013 using the terms “laparoscopic donor nephrectomy,” “retroperitoneoscopic donor nephrectomy,” and “live donor nephrectomy.” Inclusion criteria were as follows: (1) a case series of 100 or more cases and (2) donor nephrectomy performed using either LIA or RA without hand assistance. We collected the following data: intraoperative variables (length of time of surgical procedure, kidney warm ischemia time, estimated blood loss, blood transfusion rate, and whether there was conversion to open surgical procedure), operative complications (vessel injury, adjacent organ injury, bowel injury, chylous ascites), whether a repeat operation was needed, length of hospital stay, and whether patients required readmission. In addition, data on ureteral complications, delayed graft function, and graft loss in the recipients were included. Review papers that repeated cohorts were excluded. Data extraction was conducted by the same author using an established data collection spreadsheet (Table 1). When more than 1 paper described the same study, the publication with the most comprehensive data was used.

Statistical analyses
Meta-analysis was undertaken using the Meta Package in R Version 3.0.1.¹⁰ We used I2 statistics to describe the percentage of variation across studies due to heterogeneity rather than chance.¹¹ When high I2 statistics indicate substantial heterogeneity, meta-analysis is often omitted, or a random effects model can be used; however, results must be interpreted with caution. The random effects model assumes that the effects in the different models follow a distribution, and confidence intervals combine between-study and within-study variances.¹² The outcomes of intraoperative variables, donor surgical complications and graft-related urologic complications, delayed graft function, and graft loss in the recipients were summarized using means and 95% confidence intervals.

Overall, 1084 papers for LIA and 75 papers for RA were identified in the literature search. Excluding the papers with case volumes of less than 100 patients, 66 papers that reported on use of LIA and 11 papers that reported on use of RA met our selection criteria. After we excluded studies that used the hand-assisted technique, 55 papers that reported on use of LIA and 6 papers that reported on use of RA were included in this review. A summarized diagram for the literature search is shown in Figure 1.

Details of included papers are listed in Table 1. Most of the published studies (90.2%) reported on use of LIA, which has been much more widely used than RA in living-donor nephrectomies in the United States, North America, Australia, and the United Kingdom. The RA has been used in Asia and some European countries.

There were no significant differences between these 2 surgical approaches in terms of surgical time, kidney warm ischemia time, estimated blood loss, bowel injury, chylous ascites, rate of repeat surgical procedures, ureteral complications, and graft loss. However, patients whose surgeons used RA had significantly lower transfusion rates, fewer reports of delayed graft function, less vessel injury, and less conversion to open surgical procedure than patients whose surgeons employed LIA. It was noted that the length of hospital stay was longer when RA was used. Our meta-analysis results are detailed in Table 2.

Living-donor nephrectomy is a unique surgical procedure in that healthy people are subjected to surgical risks for the benefit of others, usually a family member or a friend. Before the laparoscopic era, living-donor nephrectomy was performed by open surgical procedure using a flank incision and a retroperitoneal approach to the kidney. The major complication rate was about 2%.^9,70 Alternative techniques have included using a midline or subcostal abdominal incision via the intraperitoneal approach.

Since 1994, minimal invasive laparoscopic living-donor nephrectomy has gradually become the preferred technique due to its multiple benefits: less pain, better cosmetic outcome, quicker convalescence, and fewer complications.^{71,
72} The successful application of laparoscopic donor nephrectomy has reduced some distress to living kidney donors with equally successful outcomes of kidney graft function.^2,4-6Over the past 2 decades, laparoscopic living-donor nephrectomy has been widely accepted and become the standard of care in most transplant units.

Currently, there are various laparoscopic techniques for living-donor nephrectomies including LIA and RA, with or without hand-assisted techniques. In this review, we found that LIA has been more widely used than RA (9:1). Its popularity has been explained by a better working space, the easy orientation of abdominal anatomy under laparoscopic vision, and the possible influence of general surgeons who are more accustomed to the intraperitoneal approach. However, in open donor nephrectomy, the retroperitoneal approach with flank incision has been often used because it provides direct access to the kidney without entering the intraperitoneal cavity and interfering with abdominal organs.^{2, 8} This advantage of direct access to the kidney also applies to the RA in minimally invasive donor nephrectomy.

In 1994, living-donor nephrectomy with RA was first reported by Yang and associates.⁷³ It has been widely used in Japan, India, and China.^14-17 In view of the kidney’s anatomy, this approach provides quick access to the renal artery and renal vein. The ureter is usually visualized after establishing the workspace. Kidney dissection can be conducted without needing to retract the spleen on the left side or retract the liver on the right side. Therefore, the risk of lacerating the spleen or liver is completely preventable. Disturbance to the bowel can also be avoided, as there is no need to enter the intraperitoneal cavity. In addition, this approach is favored in dealing with lumbar veins as it allows direct visualization during donor nephrectomy.^15-17Therefore, the risk of vessel injury during donor nephrectomy is less when using the RA.

This literature review demonstrates that vessel injuries are fewer and thus blood transfusion rates are lower when RA is used. Rates of conversion to open surgical procedure and delayed graft function are also lower in patients who had RA. This result may be partly related to the surgeon’s experience as more experienced surgeons have less vessel injury and surgical complications. There was no significant difference in terms of surgical time, kidney warm ischemic time, and ureteral complications between the 2 approaches. The finding of a fewer number of vessel injuries with RA is similar to that reported in a systematic review by Fan and associates⁷⁴ in a comparison of laparoscopic intraperitoneal versus retroperitoneoscopic radical nephrectomy for renal cell carcinoma, in which the overall intraoperative complication rate was demonstrated to be significantly lower (odds ratio, 2.12; P = .003) and the surgical time was shorter with RA. These results are consistent with the anatomic explanation, as the retroperitoneal approach provides direct access to the renal hilum, whereas the intraperitoneal approach requires mobilizing the colon. Furthermore, use of RA avoids conversion to open surgical procedures due to adhesions from previous abdominal surgical procedures. It also preserves the donor’s virgin abdomen and thus reduces the chance of complications during any future abdominal surgical procedure. The longer hospital stays in studies of RA are probably due to coverages differences in health care systems.

The limitation of this study is that most of the papers were clinical retrospective studies. Some surgical parameters were missing. Therefore, the high degree of study heterogeneity is obvious, suggesting that there is an urgent need for consistency and standard procedures in reporting the outcomes of laparoscopic living-donor nephrectomy. This will ensure that the results can be combined in meta-analyses that assess the outcomes of new surgical procedures to define a criterion standard technique.

In conclusion, use of RA in living-donor nephrectomy has the advantages of quick access to renal vessels, better visualization of lumbar veins, and less interference with abdominal organs. Our meta-analysis shows that blood transfusion rates are lower and delayed graft function, vessel injuries, and conversions to open surgical procedure are fewer in patients who had RA. Therefore, in living-donor nephrectomy, RA may be better than LIA. Further study of the techniques for living-donor nephrectomy is recommended to define a standard and thus, to minimize the surgical risks and complications.

Volume: 14 Issue: 2 April 2016

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