Laparoscopic and Robotic Urology
Techniques in laparoscopic donor nephrectomy
Professor David Nicol, Department of Renal Transplantation, Royal Free Hospital, Pond Street, London NW3 2QG, UK. e-mail: firstname.lastname@example.org
What's known on the subject? and What does the study add?
Innovations in laparoscopic surgery have provided transplant surgeons with a range of techniques as well as a vast array of minimally invasive instruments. Whilst randomized control trials have compared open and laparoscopic donor nephrectomy, there is a paucity of high quality data comparing different laparoscopic approaches. This article summarizes the main techniques of laparoscopic donor nephrectomy currently in use and reviews the evidence available for each. In addition, controversial aspects of donor nephrectomy are examined, including the technological advances applicable to this operation.
Increasing numbers of living donor kidney transplants are being performed worldwide, and the majority of donor operations are now laparoscopic. Transperitoneal ‘pure’ and hand-assisted laparoscopic donor nephrectomy are the two most commonly performed procedures, although retroperitoneal approaches are advocated by some centres. Controversy persists with respect to the technical aspects of donor nephrectomy, including both the approach and the method of ligation of the hilar vessels. More recently, robot-assisted, laparo-endoscopic single site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) -assisted donor nephrectomy have also been performed, further increasing the number of options available, but creating uncertainty as to the ideal approach.
delayed graft function
hand-assisted laporoscopic donor nephrectomy
laparo-endoscopic donor nephrectomy
robot-assisted laparoscopic single-site surgery
natural orifice transluminal endoscopic surgery
open donor nephrectomy
robotic-assisted donor nephrectomy.
Renal transplantation is the preferred treatment of most patients with end-stage renal failure . Outcomes after transplantation are superior with the use of live-donor kidneys, compared with those from deceased donors . The technique of laparoscopic donor nephrectomy (LDN) has evolved as a viable alternative to open donor nephrectomy (ODN). The latter procedure may result in a protracted convalescence  and a high rate of long-term complications including wound-related morbidity . Both a recent meta-analysis  and systematic review  have suggested that LDN results in fewer complications, shorter hospital stay and faster return to work compared with ODN.
The ‘pure’ transperitoneal technique of LDN originally described by Ratner et al.  involved the use of standard laparoscopic instruments to approach the kidney via the peritoneal cavity. This has evolved into a range of alternative approaches including hand-assisted transperitoneal , retroperitoneal  and robotic-assisted  donor nephrectomy. These newer techniques have been advocated based on potential advantages including enhanced donor safety and a shorter learning curve for laparoscopic-naïve surgeons .
Over the last decade there has been a rapid increase in the number of live-donor renal transplants, accompanied by an increase in the proportion of the donor operations performed by laparoscopic techniques. In the UK, only 6% of live-donor nephrectomies involved a laparoscopic approach in 2000 . This has risen to approximately 90% in 2010–11 (unpublished data from NHS Blood and Transplant). This parallels the United States, where the percentage of donor operations performed using a laparoscopic approach rose from 49% in 2000 to 92% in 2008 .
In this review, we provide an overview of the current techniques in laparoscopic donor nephrectomy, examining the evidence for these, and future advances in this procedure.
‘PURE’ TRANSPERITONEAL LAPAROSCOPIC DONOR NEPHRECTOMY
The ‘pure’ transperitoneal LDN originally performed by Ratner in 1995  remains the technique of choice in many transplant centres [14–16], particularly those with prior experience of other complex laparoscopic procedures. The procedure is performed in the lateral decubitus position, typically using four laparoscopic ports. For a left nephrectomy, the descending colon is mobilized medially and the ureter identified at the pelvic brim, with preservation of the peri-ureteral tissue to minimize ischaemia and the risk of ureteric complications . The renal artery and renal vein are ‘skeletonized’, and the adrenal and gonadal veins may be ligated at their junction with the renal vein to maximize vessel length. Attachments of the kidney are then divided to achieve full mobilization. The renal vessels are divided, usually with a linear stapler , and the organ is retrieved either by hand or using a retrieval bag, typically through a pfannenstiel incision .
HAND-ASSISTED TRANSPERITONEAL LAPAROSCOPIC DONOR NEPHRECTOMY
Hand-assisted laparoscopic donor nephrectomy (HALDN) was originally described in 2001 , and has similar advantages over ODN with regards to postoperative recovery as ‘pure’ LDN [20,21]. Approximately two-thirds of transperitoneal LDN procedures in the UK are currently performed with hand-assistance (unpublished data from NHS Blood and Transplant). The technique utilises an air-tight port through which one hand of the operating surgeon can be placed, in lieu of two of the instrument ports used in ‘pure’ LDN. The steps involved in HALDN are similar to those in ‘pure’ transperitoneal LDN. The presence of a hand within the peritoneal cavity provides tactile feedback allowing manual manipulation of tissue for dissection and mobilization of the kidney . Potential advantages of HALDN include a shorter learning curve (particularly during the transition from ODN) , shorter operative and warm ischaemic times than ‘pure’ LDN  and the capacity to readily control haemorrhage by manual pressure .
COMPLICATIONS OF TRANSPERITONEAL LDN
LDN appears a safe procedure, with 0% mortality reported in several large series [14–16,23]. There have, however, been deaths following LDN due to haemorrhage , carbon dioxide gas embolism  and pulmonary embolism , and the overall mortality rate is regarded as approximately 0.03% . The risk of a major intra-operative haemorrhage during LDN is 0.6–1.6% [23,27]. Conversion to open surgery has been reported to occur in 0–13% of cases, although in most large series conversion rates of 1–2% are reported [14,16,23,27,28]. LDN has an overall complication rate of approximately 10% [5,29].
‘PURE’ LDN VS HALDN – SUMMARY OF THE EVIDENCE
Currently, there is limited level one evidence comparing these techniques. A systematic review has demonstrated that ‘pure’ LDN results in longer operative (mean difference 30 min, P= 0.02) and warm ischaemic times (mean difference 75 s, P < 0.001) than HALDN . Another review has suggested that ‘pure’ LDN results in higher rates of intra-operative complications (5.2% vs 2.0%, P < 0.01) and conversion to an open procedure (0.8% vs 0.4%, P= 0.047) than HALDN . In contrast, a meta-analysis of laparoscopic nephrectomy for urological indications reported a higher rate of wound complications with HALDN compared with ‘pure’ LDN (2.2% vs 0.5%, P= 0.02) . A large retrospective study (>5000 patients) also demonstrated that the frequency of re-operation for incisional hernia is higher following HALDN compared with LDN (0.5% vs 0.03%, P= 0.001) . Despite these specific findings, there appears to be no overall difference in the incidence of postoperative complications, hospital stay or recipient complications between these two techniques [30,31]. The proposed advantages and disadvantages of ‘pure’ LDN and HALDN, compared with ODN are summarized in Table 1. Large patient series of LDN are summarized in Table 2.
Table 1. Advantages and disadvantages of open donor nephrectomy (ODN), hand-assisted (HALDN) and ‘pure’ laparoscopic donor nephrectomy (LDN)
|Ease of learning||+++||++||+|
|Short operative time||+++||++||+|
|Short ischaemia time||+++||++||+|
|Return to work||+||+++||+++|
Table 2. Large patient series of laparoscopic donor nephrectomy
|Chin et al. ||2007||‘Pure’ transperitoneal||431||86.2%||1.8%||9.8%||DGF 3.0%|
|Harper et al. ||2010||‘Pure’ transperitoneal||750||98.8%||0.4%||5.5%||Not described|
|Jacobs et al. ||2004||‘Pure’ transperitoneal||738||96.0%||1.6%||17.1%||DGF 2.6%|
|Posselt et al. ||2004||‘Pure’ transperitoneal||387||86.0%||0.2%||5.9%||DGF 4.7% PNF 0.3%|
|Dols et al. ||2009||‘Pure’ transperitoneal||283||44.0%||4.6%||11.7%||PNF 1.1%|
|Chandak et al. ||2009||Hand-assisted transperitoneal||144||90.3%||0.7%||16.0%||Not described|
|Buell et al. ||2002||Hand-assisted transperitoneal||100||83.0%||2.0%||22.0%||DGF 3.0%|
|Horgan et al. ||2007||Robotic-assisted transperitoneal||273||98.1%||1.8%||10.3%||PNF 0.7%|
|Gorodner et al. ||2006||Robotic-assisted transperitoneal||209||100%||1.9%||5.7%||PNF 1.0%|
|Kohei et al. ||2010||‘Pure’ retroperitoneal||425||96.5%||0.2%||4.9%||DGF 1.4%|
|Wadstrom et al. ||2011||Hand-assisted retroperitoneal||413||97.6%||2.4%||7.7%||PNF 1.2% DGF 2.9%|
ROBOTIC-ASSISTED TRANSPERITONEAL DONOR NEPHRECTOMY
The use of the da Vinci surgical system to assist in LDN was first reported in 2002 . Robotic assistance provides additional freedom of movement of instruments, three-dimensional vision and elimination of tremor . Robotic-assisted donor nephrectomy (RADN) can be performed as either a ‘pure’ laparoscopic procedure  or with hand-assistance . Its safety has been demonstrated , but there are no large studies comparing RADN with ‘pure’ LDN or HALDN. Advocates of the technique cite improved donor safety and fewer complications , but use of the robotic system has substantial cost implications , and the absence of haptic feedback remains a deterrent to its utilisation by many surgeons .
RETROPERITONEOSCOPIC DONOR NEPHRECTOMY
Retroperitoneal approaches to the kidney by both ‘pure’ laparoscopic  and hand-assisted  techniques have been developed. Approximately one-third of all LDN procedures in the UK are performed using a retroperitoneal approach (unpublished data from NHS Blood and Transplant). It has the potential advantage of improved donor safety compared with transperitoneal LDN, as intra-peritoneal organs such as the colon and spleen are theoretically less likely to be injured . Avoiding entry into the peritoneal cavity may also prevent post-operative complications such as ileus and internal herniation , but the smaller working space compared with transperitoneal LDN means that this technique may be more demanding for the surgeon .
The procedure is commonly performed with hand-assistance, conferring the same potential advantages of shorter operating and warm ischaemic time, and ability to control haemorrhage as HALDN . The surgeon's hand bluntly dissects the peritoneum away from the abdominal wall until the kidney is reached, and after insertion of laparoscopic ports, the nephrectomy is performed in a similar way to transperitoneal HALDN . Despite its proposed benefits in donor safety, retroperitoneoscopic LDN is less commonly performed than transperitoneal LDN, possibly due to the fact that surgeons are more familiar with the transperitoneal approach to the abdominal organs. It is possible, however, to achieve the transition from transperitoneal to retroperitoneoscopic LDN with a short learning curve, without detrimental effects on donor or recipient outcomes .
ANATOMICAL AND TECHNICAL CONSIDERATIONS
In the presence of a single renal artery supplying each kidney, the majority of centres prefer to perform a left LDN , as the shorter right renal vein results in a technically more challenging venous anastomosis in the recipient, leading to a small but significant increase of graft loss at 90 days (right 3.8% vs left 2.5%, OR = 1.49, P < 0.01) . Historically, this also resulted in many centres preferring left LDN even in the presence of multiple left renal arteries . The presence of multiple renal arteries, however, results in higher rates of ureteric complications in the recipient compared with kidneys with a single artery (16.7% vs 3.2%, P= 0.001) . In addition, transplantation of kidneys with multiple arteries has been shown to produce higher rates of graft loss than in organs with single vessels (HR 2.30, 95% CI 1.05, 5.09, P= 0.038) . As ‘pure’ and hand-assisted right LDN have been shown to be feasible and safe [48,49], with shorter operative times than left LDN , right LDN is now regarded as an acceptable alternative to left LDN in the presence of multiple renal arteries supplying the left kidney but not the right . Therefore, it is the practice of many units (including the authors') that in the presence of unilateral multiple renal arteries, the kidney with a single artery is preferred, irrespective of laterality.
OTHER TECHNICAL CONSIDERATIONS
The gonadal vein and vascularity of the ureter
Some surgeons divide the gonadal vein proximally and distally, and include it with the specimen in order to protect ureteric vascularity. This is thought to be the cause of postoperative ipsilateral orchalgia, which occurs in 6.2–9.6% of male donors [52,53]. Large studies, however, have demonstrated that leaving the gonadal vein in situ does not lead to increased ureteric complications in the transplant recipient  and prevents orchalgia .
The routine intra-operative administration of systemic heparin to prevent thrombotic complications in the recipient, such as renal vein thrombosis, is now considered unnecessary by most surgeons. Although there are no randomized controlled trials, retrospective studies have shown identical graft outcome in patients whose donors did not receive heparin, compared with those that did [54–56].
METHODS OF VASCULAR CONTROL
Several devices are available for the ligation and division of the main renal vessels, and the venous tributaries that are encountered during LDN (gonadal, adrenal and lumbar veins) . All of these devices are subject to ‘misfire’ and malfunction. Reported failure rates are 3.0% for staplers, 4.9% for titanium clips and 1.7% for locking clips . Polymer ligating clips have been a popular method of securing the renal artery, as they are cheaper than vascular staplers  and may provide greater vessel length . The use of these clips to ligate the renal artery now contravenes manufacturer's advice, however, following reports of haemorrhage after clip dislodgement . Based on a large multi-centre review, the use of any ‘non-transfixion’ technique to secure the renal vessels (i.e. locking or non-locking clips) appears to be associated with more severe complications following haemorrhage compared with ‘transfixing’ techniques such as linear stapling . Therefore, it is the current practice of most units to ligate and divide the main renal vessels using a vascular stapler.
Stapler misfire rates can be reduced by avoiding the use of titanium clips around the hilar structures , an approach made possible by intra-corporal knot-tying (the authors' current practice), bipolar diathermy, or the use of devices such as the Ligasure (Covidien PLC, Boulder, Co, USA)  to control renal vein tributaries. Stapler misfire usually manifests intra-operatively, which may necessitate rapid conversion to an open procedure to control major haemorrhage . In contrast, clip dislodgement may occur several hours following the procedure resulting in fatal haemorrhage on the ward .
Vascular staplers may be ‘cutting’ such as the Endopath ETS (Ethicon Ltd, Wokingham, UK) and Endo-GIA (Covidien PLC) or ‘non-cutting’ such as the Endo-TA (Covidien PLC). Some surgeons prefer to use non-cutting staplers, which have fewer rows of staples than cutting staplers, to increase vessel length , particularly when controlling the right renal vein . Some of this advantage is lost, however, as the Endo-TA does not articulate . The use of a non-cutting stapler to increase vessel length is corroborated by one in vitro study  but not by another .
METHODS OF SPECIMEN RETRIEVAL
With ‘pure’ LDN, there are two main methods of extraction of the kidney – the use of a specimen retrieval bag or the surgeon's hand. With use of a specimen retrieval bag, minor lacerations have been reported in up to 7% of all organs retrieved . Transection of the renal pelvis by the metal ring contained within these devices has also been reported . The authors' current practice is to insert a hand through the pfannenstiel incision after vessel division, to retrieve manually the kidney under laparoscopic vision without the use of a device. A hand-port device may be used purely for the purpose of specimen retrieval after ‘pure’ LDN, in an attempt to minimize warm ischaemia time .
The use of LESS technology for LDN aims to decrease morbidity, and improve recovery times and cosmesis after living kidney donation . The LESS device, which can accommodate up to four laparoscopic instruments is placed through a 4–5 cm peri-umbilical incision, and the procedure performed using standard or articulating laparoscopic instruments . Comparative studies have shown that LESS LDN results in faster postoperative recovery than ‘pure’ LDN after donation, but is associated with longer warm ischaemic times (which do not appear to affect graft outcome) [71,72] and additional costs .
The use of NOTES within LDN is currently limited to trans-vaginal extraction of the specimen [74,75] and instrumentation through the trans-vaginal port . This is intended to reduce further the trauma of living donation but is obviously applicable only to a sub-set of donors. As experience with these techniques develops and further technological advances arrive, LESS and NOTES may become the next major advances in living kidney donation.
LDN is an established technique of living kidney donation, and in its various forms appears to be the procedure of choice in most transplant centres. It can be safely performed by transperitoneal or retroperitoneal routes, with or without hand assistance. Although there are distinct advantages and disadvantages of each of these techniques, they have similar outcomes for the donor and the recipient. As no particular approach can be identified as clearly superior, surgeons are best performing that in which they have training and experience, in the interests of patient safety.
CONFLICT OF INTEREST