A Randomized, Prospective, Parallel Group Study of Laparoscopic vs. Laparoendoscopic Single Site Donor Nephrectomy for Kidney Donation

Abstract

Few prospective, randomized studies have assessed benefits of laparoendoscopic single site donor nephrectomy (LESS-DN) over laparoscopic donor nephrectomy (LDN). Our center initiated such a trial in January 2011, following subjects randomized to LESS-DN vs. LDN from surgery through 5 years post-donation. Subjects complete recovery/satisfaction questionnaires at 2, 6, and 12 months post-donation; transplant recipient outcomes are also recorded. 100 subjects (49 LESS-DN, 51 LDN) underwent surgery; donor demographics were similar between groups, and included a predominance of female, living unrelated donors, mean age of 47 years who underwent left donor nephrectomy. Operative parameters (overall time, time to extraction, warm ischemia time, blood loss) were similar between groups. Conversion to hand-assist laparoscopy was required in 3 LESS-DN (6.1%) vs. 2 LDN (3.9%; P=0.67). Questionnaires revealed 97.2% of LESS-DN vs. 79.5% of LDN (P=0.03) were 100% recovered by two months after donation. No significant difference was seen in satisfaction scores between the groups. Recipient outcomes were similar between groups. Our randomized trial comparing LESS donor nephrectomy to LDN confirms that LESS-DN offers a safe alternative to conventional LDN in terms of intra- and post-operative complications. LDN and LESS-DN offer similar recovery and satisfaction after donation.

Introduction

Laparoscopic donor nephrectomy (LDN) has become the standard of care at most major academic centers due to significant improvement in donor morbidity compared to open donor nephrectomy (ODN). Traditionally performed via 3 to 5 small incisions, advantages of LDN include decreased morbidity, improved cosmesis, and shorter recovery times. Long term studies confirming equivalent complication rates and graft outcomes to ODN have helped increase the potential pool of living kidney donors (1–5).

Laparoendoscopic single site (LESS) surgery represents the next step in the evolution of laparoscopic surgery, performed through a single small incision, often partially concealed at the umbilicus. In addition to cosmetic advantages, patients may experience less postoperative pain and fewer port site related complications. Several institutions have reported using LESS for live donor nephrectomy (LESS-DN) and other therapeutic/reconstructive renal procedures, showing similar perioperative outcomes and equivalent complication rates, with varying results related to donor recovery and cosmesis (6–10). Meta-analysis of 27 studies comparing LESS vs. laparoscopic nephrectomy in patients undergoing radical or partial nephrectomy for cancer, donor nephrectomy, or mixed procedures found LESS to be a safe and effective alternative with potential benefits of reduced pain, shorter recovery, and improved cosmesis (11).

To date, the largest trial comparing transumbilical LESS-DN to conventional LDN randomized 50 living kidney donors and utilized a primary endpoint of pain scores (assessed for 96 hours after surgery) (12). The study found that LESS-DN patients did benefit from less pain and shorter hospital stays compared to the conventional group, with equivalent graft function in the kidney recipients. There was a longer warm ischemia time in the LESS-DN group, and donor quality of life, body image, and cosmesis scores were similar between groups. This trial excluded donors undergoing right donor nephrectomy, those with multiple vessels, and initially excluded donors with a BMI > 25 kg/m² (relaxed to > 27 kg/m²).

Another trial randomized 29 patients to LESS-DN (utilizing a Pfannenstiel incision) or conventional LDN, blinding the donor and post-operative caregiver by utilizing sham butterfly stiches and bandages over the LESS-DN group’s non-existent port site incisions (13). The primary endpoint of this study was also pain scores, however the study was terminated prior to enrollment of the targeted 40 subjects per arm. Results included no difference in intra-operative variables, length of stay (LOS), or post-operative pain medication. The LESS-DN group reported lower pain scores on post-operative days (POD) 1 and 2.

Our center began utilizing LESS-DN as the standard of care in August 2009, after having performed more than 1,000 LDN procedures since 1998. Retrospective review of our experience with 50 LESS-DN compared to 50 matched LDN showed that donors may benefit from LESS-DN in the areas of faster return to pre-donation baseline functional status (defined as time to 100% recovery) and improvement in surgical scar satisfaction (14). Recovery parameters in the LESS-DN vs. LDN groups, respectively, included time to return to work (11.0 ± 2.7 vs. 11.6 ± 3.1 days; P=0.32), normal activities (18.5 ± 3.3 vs. 19.6 ± 3.5 days; P=0.10) and donor feeling of “100% recovery” (24.4 ± 5.3 vs. 27.0 ± 4.9 days; p=0.01). When rating their overall surgical scar satisfaction, the LESS-DN group gave higher mean ratings (9.78 vs. 7.19, p=0.004).

Based on our initial experience, we hypothesized that LESS-DN offers a safe alternative to LDN for both donors and the recipients of their organs. In order to more formally assess LESS-DN vs. LDN from the donor’s perspective, we designed a randomized, controlled, parallel group trial with a primary objective to compare donor recovery and satisfaction between LESS-DN and LDN in subjects undergoing living donor nephrectomy for the purpose of transplantation.

MATERIALS/METHODS

This clinical trial is registered at www.clinicaltrials.gov (NCT01236326), and the protocol is approved by the Institutional Review Board of Weill Cornell Medical College (protocol # 1009011249). Informed consent was obtained from each participant prior to enrollment.

Participants

Inclusion criteria included all potential kidney donors who were scheduled to undergo donor nephrectomy during the period that the study was open to enrollment, and were consented to participate by their physician. There were no exclusion criteria. Consenting subjects were randomized by the research coordinator using stratified and blocked randomization generated by the study statistician (described below): LDN (Group 1), and LESS-DN (Group 2). The left kidney was chosen preferentially if renal vasculature and function were comparable. Right organs were chosen if there were multiple vessels on the left or if there was more than 10% difference in function, as measured by scintigraphy.

All LDN donors underwent transperitoneal laparoscopic nephrectomy in the lateral decubitus position. Initial abdominal access was achieved using a Veress needle. The peritoneal cavity was insufflated to 10 to 15 cm H2O. Three port sites (1 × 12 mm and 2 × 5 mm ports) were used for dissection. The Endo-GIA™ stapler (Coviden, Mansfield, MA) was used to divide the renal artery and vein. The kidney was removed through a 5 to 6 cm Pfannenstiel incision using an EndoCatch™ bag (Coviden, Mansfield, MA). For right nephrectomy, exposure is achieved by dividing the triangular and coronary ligaments to retract the liver, kocherizing the duodenum and incising the peritoneum along the lateral line of Toldt. To maximize venous length the Endo-TA stapler (US Surgical, Norwalk, CT) is used to divide the right renal vein flush with the vena cava. For hand-assisted laparoscopy (HAL), access is achieved via a GelPort^® device (Applied Medical, Rancho Santa Margarita, CA) placed through the Pfannenstiel incision.

For LESS-DN procedures, patients are placed in a modified flank position. A 5 cm vertical periumbilical incision is made with the abdominal skin on stretch. After creating a vertical midline anterior rectus fasciotomy, the abdomen is entered. The GelPOINT^® device (Applied Medical, Rancho Santa Margarita, CA) with 3 trocars already in place is inserted into the abdomen and pneumoperitoneum is established. Two 5 to 10 mm and one 15 mm trocar are used. A bariatric 10 mm rigid laparoscope is used through the 15 mm port with a right angle attachment for the light cord to maximize space for triangulation. For right LESS-DN, a fourth trocar is placed through the GelPOINT^® and a Diamond-Flex^® retractor (Carefusion, Waukegan, IL) is used for exposure after mobilization of the right lobe of the liver. After kocherization of the duodenum to expose the inferior vena cava the remainder of the procedure is similar to left LESS-DN except that division of the right adrenal vein is typically not needed. For conversion to HAL, access is achieved via the pre-existing periumbilical incision and 2 to 3 extra-umbilical trocars are then added.

The LESS-DN surgical technique essentially duplicates standard LDN. For left LESS-DN the descending colon, pancreas and spleen are mobilized generously en bloc without the need for continuous retraction. The ureter and gonadal vein are identified and lifted off the psoas muscle together, maintaining periureteral attachments, and dissected toward the hilum. If present, the lumbar vein is divided between titanium clips. As in LDN, the renal vein is skeletonized, the adrenal vein is divided between titanium clips and the adrenal gland is released from the upper pole. The renal artery is dissected down to its aortic origin and the interaortocaval region is skeletonized. Lastly, the posterior attachments are dissected free from the kidney. A 12 mm trocar replaces one 5 mm trocar in anticipation of using the Endo GIA^® vascular stapler.

When the recipient team is ready, the ureter and gonadal vein are divided together at the pelvic brim. The renal artery and then the vein are divided using the vascular stapling device. An EndoCatch™ bag is introduced. The allograft is gently entrapped and extracted by removing the gel cap. The graft is perfused with ice-cold Custodial HTK solution (Odyssey Pharmaceuticals, East Hanover, NJ). If needed, the fascial incision is extended 1 to 2 cm to facilitate graft removal with care taken to leave the overlying skin intact. Fascia and skin are closed in standard fashion after ensuring adequate hemostasis. No articulating or specialized laparoscopic instruments are needed and no extra-umbilical incisions are made.

The primary endpoint of the study was patient self-reported “return to 100%”, as measured by the number of days post-surgery that the patient reports return to 100% functioning capacity. Secondary objectives included operative data, post-operative data (within 30 days), donor subjective questionnaire, long-term follow-up (30 days to 5 years), and kidney transplant recipient outcomes.

The operative time to allograft extraction was the interval from operative field skin preparation to organ extraction. The total operative time was the interval from skin preparation to skin closure. Warm ischemia time was the interval from renal artery occlusion to back-table perfusion with CUSTODIOL HTK. The LOS was the interval from admission to the hospital prior to donation until discharge. Operative complications included any unexpected event leading to injury to the donor or donor kidney. Patients were discharged once tolerating a regular diet, able to ambulate, and pain was controlled. Pain scores were measured using a visual analog pain scoring system.

Questionnaires (Supplemental Figures 1A and 1B) were administered anonymously by mail to reduce chance of bias (questions were previously part of routine post-operative visits with donor surgeon). The 2-month questionnaire assessed recovery time parameters, which include the time to return to work, “normal” activity, and “100% recovery” and questions regarding how the donors rated their surgical scar satisfaction and overall satisfaction with the donation process (both on a scale of 1 (displeased) to 10 (extremely pleased)). Donors were asked to indicate any new medical issues since donation and any hospital re-admissions that occurred. The 6 and 12-month questionnaires again assessed satisfaction with the scar(s) and donation process, and inquired about any new medical issues (such as development of hernia, hypertension, renal insufficiency, bowel obstruction, chronic pain, urethral stricture) or hospitalizations.

Kidney transplant recipient outcomes included assessment of ureteral complications or delayed graft function (DGF) (defined as need for dialysis within 7 days of transplant), patient and graft survival and graft function (serum creatinine) at 1, 3, 6, and 12 months after transplant.

Data Collection

Clinical data was recorded in the electronic medical record and/or paper chart on the day of the operation and throughout the subject’s hospital stay and outpatient follow-up visits. These clinical variables were then transcribed into the secure electronic database for this study. Questionnaires contained the subject’s identification number and initials, and were mailed to study subjects with a self-addressed stamped envelope to encourage return. Upon receipt by the research coordinator, questionnaire data was entered into the secure electronic study database.

Statistical Considerations

Sample size

The primary endpoint of the study was the mean/median number of days post-surgery required for each group to return to 100% functioning capacity. From preliminary data of our entire LESS-DN experience, the mean (± SD) number of days required for return to 100% capacity was 21.4 ± 5.3 and 29.6 ± 4.9 in the LESS-DN and LDN groups, respectively (i.e., mean difference between groups = 8.2 days). With approximately 50 patients in each group, this study allowed for the detection of a mean difference in the number of days required for return to 100% capacity (between the two groups) of ≥ 3 days with 80% power and a two-sided alpha level of 5%. A 95% confidence interval for the mean difference in the number of days required for return to 100% capacity between the two groups could be constructed to be within ± 2.1 days of the true difference in the mean number of days required for return to 100% capacity.

Statistical Analysis

Descriptive statistics stratified by LESS-DN/LDN group status, were calculated for 1) demographic factors, 2) intraoperative complications and parameters, and 3) postoperative parameters and convalescence. The two-sample t-test and Wilcoxon rank-sum test was used to compare the mean and median number of days required for return to 100% capacity, respectively, between the two groups. Secondary endpoints were compared using the two-sample t-test, Wilcoxon rank-sum test, chi-square test, or Fisher’s exact test, as appropriate. All p-values are two-sided with statistical significance evaluated at the 0.05 alpha level. Ninety-five percent confidence intervals were calculated to assess the precision of the obtained estimates. All analyses were performed in SAS Version 9.3 (SAS Institute Inc., Cary, NC) and STATA Version 13.0 (StataCorp, College Station, TX).

Randomization

Stratified and blocked randomization was performed in this study. Randomization was stratified by the following three parameters: 1) laterality, 2) BMI ≥ 30, and 3) vascular complexity (> 1 artery). A series of randomized blocks of 4 was generated for each laterality/BMI/vascular complexity stratum with a 1:1 allocation ratio. This provided insurance that after 4 patients were enrolled in any given laterality/BMI/vascular complexity stratum, there were 2 patients assigned to the LESS-DN group and 2 patients assigned to the LDN group.

RESULTS

Recruitment

Enrollment began January 2011 and ceased May 2012; 105 subjects were enrolled and randomized during this period. Five subjects were withdrawn due to donation not going forward (n=4; 3 in LDN group and 1 in LESS-DN group) and 1 subject who had elective gynecologic surgery at the same time as the nephrectomy (LDN group), leaving 100 subjects for analysis. All donors will be followed for 5 years after donation; this initial report presents one-year of follow-up data for donors and the recipients of their kidneys.

Donor Demographics

Table 1 summarizes the demographic characteristics of the living donors; mean age at donation was 47 years, and the majority were female and not related to the recipient. Less than 10% of donors underwent right nephrectomy, about 70% had a BMI less than 30 kg/m², and 12% of donor kidneys had multiple arteries.

Table 1.

Donor Demographics

	Conventional LDN N=51	LESS-DN N=49	P
Age at Donation (years)	47.4 ± 11.5	46.8 ± 11.9	0.78
Gender (female), n (%)	29 (56.9%)	29 (59.2%)	0.81
Race, n (%)			0.36
African American	9 (17.6%)	5 (10.2%)
Caucasian	31 (60.8%)	28 (57.1%)
Hispanic	9 (17.6%)	10 (20.4%)
All Other	2 (3.9%)	6 (12.2%)
Relationship to Recipient, n (%)			0.67
Living Related	24 (47.1%)	21 (42.9%)
Living Unrelated	27 (52.9%)	28 (57.1%)
Side of Donation (left), n (%)	48 (94.1%)	45 (91.8%)	0.71
BMI < 30, n (%)	36 (70.6%)	36 (73.5%)	0.75
Multiple Arteries, n (%)	6 (11.8%)	6 (12.2%)	0.92

Operative Characteristics, Inpatient Stay, and Complications

Table 2 summarizes the operative characteristics; overall operative time, time to extraction, need for extension of the fascial or skin incision, warm ischemia time, and estimated blood loss were similar between groups. Two patients (one per group) experienced intra-operative bleeding. The LDN patient with bleeding required conversion to HAL and transfusion, however no additional sequelae were evident. The LESS-DN patient with bleeding required conversion to HAL, experienced post-operative hypoxia, and later developed an incisional hernia at the hand-assist port site, requiring surgery approximately one-year after donation.

Table 2.

Operative Characteristics and Post-Operative Follow-Up

	Conventional LDN N=51	LESS-DN N=49	P
Overall Operative Time (min), median (range)	138 (101–214)	138 (112–240)	0.99
Time to Extraction (min), median (range)	102 (62–204)	103 (57–200)	0.85
Need for Extension of Fascial Incision (yes), n (%)	6 (11.8%)	6 (12.2%)	0.92
Need for Extension of Skin Incision (yes), n (%)	5 (9.8%)	4 (8.2%)	1.0
Warm Ischemia Time (min), median (range)	3.2 (2.3–4.8)	3.1 (2.8–5.3)	0.31
Estimated Blood Loss (mL), median (range)	50 (5–1500)	50 (5–500)	0.33
Transfusion Requirement (yes), n (%)	1 (2.0%)	0 (0%)	1.0
Intraoperative Complications, n (%)	1	1	1.0
Bleeding	1 (2.0%)	1 (2.0%)
Conversion to Hand Assist Laparoscopy, n (%)	2 (3.9%)	3 (6.1%)	0.67
Bleeding	1	1
Difficult dissection/failure to progress	1	1
Difficult mobilization (splenic attachments to upper pole)	-	1
Postoperative Complications (1st 30 days), n (%)	3 (5.6%)	6 (12.2%)	0.31
Hypoxia	-	3
Ileus	1	-
Neuropathy	1	-
Pulmonary Embolism	1	-
Superficial Surgical Site Infection	-	2
Urinary Retention	-	1
Visual Analog Pain Scores at Discharge, median (range)	2 (0–8)	3 (0–7)	0.20
Analgesic Requirements
Morphine (total # mg received), median (range)	3 (0–13)	2 (0–8)	0.68
Oral Narcotic (total # tablets received), median (range)	8 (1–22)	10 (1–18)	0.70
Length of Stay (days), median (range)	2.3 (1.4–4.4)	2.3 (1.3–4.5)	0.16
Follow-Up (months), median (range)	13.6 (0.1–27.3)	16.0 (0.1–32.0)	0.55
Re-Admission (n)
Pulmonary Embolism	1	-
Meningioma	1	-

Two patients in the LDN group (3.9%) required conversion to HAL (1 for bleeding (described above), and 1 for difficult dissection) vs. 3 patients in the LESS-DN group (6.1%; P=0.67) (for bleeding (described above), difficult dissection, and difficult mobilization). The second patient in the LDN group that required conversion to HAL reported need for a hernia repair in the 1-year questionnaire, stating that it was “unrelated to surgery”.

Visual analog pain scores prior to discharge, analgesic requirements, and LOS were similar between the two groups. Post-operative complications varied between the two groups as described in Table 2; 1 was considered severe (pulmonary embolism in LDN patient; readmitted several days after discharge). One other LDN patient was readmitted several months after donation for a benign meningioma.

Donors had a median follow-up of 14 months after donation (range 0.1 to 32 months). Complications reported by patients on their follow-up questionnaires are reported in Table 3; there were no striking differences. The one hernia in the LDN group was reported in at 12 months by a patient who had conversion to HAL for difficult dissection. Specific details about this hernia are not known since the patient did not seek care at our center, however the patient stated that it was “unrelated to surgery”. In the LESS-DN group, two patients at the 6-month mark and one at the 12-month mark reported hernias. All patients sought care at our center and two were deemed to be incisional hernias, one of which occurred at a non-umbilical port site in a patient that required conversion to HAL for bleeding.

Table 3.

Re-Admissions, New Health Issues and Surgeries Reported by Patients after 30 Days

Time Point	Conventional LDN N=51	LESS-DN N=49
2 months	Ongoing effects of nerve damage from blood draw (neuropathy ongoing from 1st 30 days postop) Ongoing treatment for pulmonary embolism (ongoing at 6 months) Emergency Department visit for abdominal pain* Suture “sticking out”	Numbness to left of incision Weight loss/decreased appetite Pain (related to being hit by car) (ongoing at 6 & 12 months)
6 months	Allergic reaction to glue used on scars Meningioma surgery* Fatigue Numbness of left inner thigh (“not major”) Feeling of “high heart rate” Muscle cramps in legs	Fatigue (ongoing at 12 months) “Stomach bulge” (non-incisional hernia; surgery at 12 months)* Incisional pain Incisional hernia (surgery between months 6 and 12)* Emergency Department visit for dehydration (gastroenteritis)
12 months	Iron deficiency anemia Hernia repair (deemed to be unrelated to donation) Gallstones Surgery to straighten deviated septum Frequent bathroom trips (seeing a urologist)	Incisional hernia (patient with bleeding/HAL; at non-umbilical port site)*

^*Patient sought care at transplant center

Donor Subjective Outcomes

Convalescence data reported by donors at 2 months post-donation is summarized in Table 4. Response rate was approximately 75% in each group. Both groups reported similar time on pain medication, days to return to work, days to normal day-to-day activities, and days to feeling 100% recovered. More donors in the LESS-DN group reported feeling 100% recovered by 2 months post-donation (97.2% vs. 79.5% of LDN patients; P=0.03).

Table 4.

Donor Convalescence Data

	Conventional LDN N=51	LESS-DN N=49	P
# Responders to 2 Month Questionnaire, n (%)	39 (76.5%)	36 (73.5%)	0.73
Days on Oral Pain Medication after Discharge, mean (SD)	7 ± 8	6 ± 4	0.60
Days before going back to work, mean (SD)	27 ± 18	24 ± 14	0.44
Days to normal day-to-day activities, mean (SD)	33 ± 25	30 ± 17	0.51
Recovered by 2 months after donation, n (%)	31 (79.5%)	35 (97.2%)	0.03
Days to 100% recovered, mean (SD)	45 ± 22	43 ± 15	0.67

As shown in Figures 1A and 1B, donor surgical scar satisfaction and overall satisfaction with the donation process was similar between groups. When asked “Based on your experience, would you recommend that a friend or family member in a similar situation undergo kidney donation?” results were similar: at 2 months, 100% of LDN and 97% of LESS-DN responded “yes”; at 6 months 100% of LDN and 94% of LESS-DN responded “yes”; at 12 months, 95% of LDN and 97% of LESS-DN reported “yes”.

Figure 1.

(A) Donor satisfaction score for surgical scar as assessed via blinded questionnaire at 2, 6, and 12 months after donation in the LDN vs. LESS-DN groups. (B) Donor overall satisfaction with donation process as assessed via blinded questionnaire at 2, 6, and 12 months after donation in the LDN vs. LESS-DN groups.

Donor Kidney Function

Figure 2 shows the pre-and post-donation serum creatinine values, which were similar at all time points.

Figure 2.

Donor serum creatinine (mg/dL) as assessed at baseline, post-donation hospital discharge, and 6 and 12 months post-donation in the LDN vs. LESS-DN groups.

Transplant Recipient Outcomes

Outcome data for the recipients of the donated kidneys is summarized in Table 5. More than 10% of kidneys were shipped to other transplant centers through participation in kidney-paired donation, which limits the granularity of data obtained for those recipients. We were able to obtain patient and graft survival, DGF, and serum creatinine data for 12 of 14 recipients outside of our center. Recipients of kidneys procured via LDN had a higher rate of DGF vs. LESS-DN (9.8% vs. 0%, P=0.057). All 5 cases of DGF appeared related to the recipient’s intra- and/or post-operative course (urine leak; cardiogenic shock in recipient; difficult renal vein anastomosis prolonging warm ischemia time; hemodynamic abnormality; intra-operative hypotension requiring multiple pressors and fluids). One recipient in each group developed a urine leak requiring surgical repair; a second LESS-DN recipient required ureteral re-implantation for ureteral stricture. Serum creatinine at 1, 6, and 12 months post-transplant are similar between groups.

Table 5.

Recipient Outcomes

Total	Conventional LDN N=51	LESS-DN N=49	P
Recipients at Cornell n (%)	43 (84.3%)	44 (89.8%)	0.60
Recipients at Outside Transplant Centers n (%)	8 (15.7%)	5 (10.2%)
Delayed Graft Function (yes), n (%)	5 (9.8%)	0 (0%)	0.057
Ureteral Complications* (yes), n (%)	1 (2.3%)	2 (4.5%)	1.0
Serum Creatinine (mg/dL), mean (SD)
1 month	1.4 ± 1.0	1.4 ± 0.5	0.71
6 months	1.3 ± 0.3	1.4 ± 0.5	0.32
12 months	1.2 ± 0.3	1.3 ± 0.5	0.23
Follow-Up (months), mean (SD)	18.3 ± 5.3	18.6 ± 5.6	0.82
Patient Survival, n (%)	50 (98.0%)	48 (98.0%)	1.0
Graft Survival, n (%)	50 (98.0%)	48 (98.0%)	1.0

^*Data available for Cornell recipients only

One recipient in each group lost their graft and expired, both losing their graft to acute kidney injury in the setting of critical illness shortly before death (one due to cardiogenic shock on POD 4 and the other due to fulminant Clostridium difficile colitis on POD 129).

DISCUSSION

Single port laparoscopy represents the next frontier in minimally invasive surgery, with potential to further reduce donor morbidity by eliminating extra-umbilical trocar sites. Since donors are healthy people undergoing surgery for purely altruistic reasons, any reduction in morbidity is beneficial to the field of living donation. Overall, the results of our randomized, controlled trial demonstrate that in experienced hands, LESS-DN provides outcomes that are similar to those of patients undergoing LDN. Based on our center’s prior experience with the LESS-DN procedure, it appeared that LESS-DN and LDN were equivalent in terms of outcomes and complications for the donor, and equivalent graft function in the recipient. This prior experience is confirmed by this randomized controlled trial. The similarities in operative parameters between the two groups demonstrate the fact that the learning curve with the LESS-DN procedure had already been seen with our earlier experience.

The main goal of our study was to assess the potential benefits to the donor afforded by the utilization of the LESS-DN procedure. Unlike our early experience, our trial did not observe any significant differences in the donors’ feelings about their recovery or cosmesis. A higher percentage of patients in the LESS-DN group reported feeling 100% recovered at 2 months post-donation (97.2% vs. 79.5% of the LDN group; P=0.03), however the time to feeling 100% recovered was similar between groups. This discrepancy might be related to missing data for 3 patients in the LDN group who reported not being fully recovered at 2 months, but who did not provide the actual time it took them to recover, despite multiple attempts to gather this information. Interestingly, the use of a blinded questionnaire administered by mail revealed a significantly longer time to recovery for all parameters, suggesting that asking these questions at clinical visits (the methodology utilized/reported in our prior publications) may have biased the responses (i.e. Donors may have felt pressure to respond positively when asked face-to-face).

It is difficult to compare our results to the randomized study performed by Kurien and colleagues due to some inherent differences in study design (12). Our study included patients excluded by Kurien, specifically those undergoing right donor nephrectomy, those with multiple arteries, and the fact that almost 30% of our donors had a BMI ≥ 30 kg/m². The primary endpoint (pain scores) in the Kurien study was assessed over a 96-hour period; the median LOS for our patients was 2.3 days (55 hours). Interestingly, the differences in pain scores noted by Kurien occurred only after 48 hours (at the 60, 72, and 90 hour mark). We also cannot compare the lack of difference in LOS in our study to Kurien’s results given that their reported length of stay was 3.92 days in the LESS-DN group and 4.56 days in the LDN group. Our program’s short LOS may reduce the chance of observing a difference between our groups.

Similar to the Kurien study, the randomized controlled trial performed by Richstone and colleagues focused on pain scores (13). This study utilized the Pfannenstiel incision as the extraction site for both procedures and for the LESS-DN group, was also the “single site” for placement of laparoscopy instruments, as opposed to the umbilicus as the single-port in our and Kurien’s studies. The Richstone study was terminated early due to accrual difficulties.

Several limitations to our study may affect our results. First was our inability to secure complete data on the donor questionnaires, since approximately 25% of subjects did not return their 2-month questionnaire, despite multiple requests and reminders. Another critique may be that we did not utilize a validated tool to assess donor recovery and satisfaction. However, we are unaware of such a tool being available, and did not feel that a standardized quality of life survey fit the study’s needs. We were interested in maintaining the same questions and time frame that were utilized and reported in our prior publications. The only difference was the administration of questionnaires via mail. As discussed above, sending the questionnaire by mail revealed a significantly longer time to recovery for all donor parameters (1.7 to 2.5× longer), as compared to previously asking these questions face-to-face, suggesting that previous responses may have been biased by donors feeling pressure to respond positively when asked at a visit. As mentioned, the “time to 100% recovery” data is discrepant with the percent-recovered data, possibly due to the missing data from 3 patients in the LDN group who were not fully recovered at 2 months post-donation. In addition, our ability to ensure clinical donor follow-up was suboptimal, a challenge faced by many transplant centers (15). As a result of the lessons learned during this study, our center has since re-structured our donor follow-up process.

There are several strengths to our study; first is the inclusion of patients undergoing right donor nephrectomy, donors with multiple arteries, and donors with a BMI ≥ 30 kg/m². Follow-up of the donors in our study is more thorough and longer than seen in previously published trials. Comparatively, the response rate of > 70% for the questionnaires at the 2-month mark is excellent. A component of the retrospective comparison performed by Barth and colleagues included administration of the 36-Item Short Form Health Survey as well as customized questions about pain, convalescence and satisfaction (10). Their survey return rate was 45%, and it is important to note that patients completed these surveys retrospectively, which may have affected their ability to respond accurately regarding events that occurred in the past. Our prospective capture of convalescence data is a strength of our study.

Compared to the significant benefits seen in the transition from ODN to LDN, the benefits seen with refinements in the laparoscopic procedure, such as LESS-DN, would be expected to be much smaller. However, any small benefit or improvement that can be provided to a patient undergoing surgery for purely altruistic reasons is important, especially if the perceived improvement may further reduce barriers to living kidney donation. In experienced hands, LESS-DN offers a safe alternative to traditional LDN and offers similar donor recovery and satisfaction.

Abbreviations

DGF

Delayed Graft Function

HAL

Hand Assist Laparoscopy

LESS

Laparoendoscopic Single Site

LESS-DN

Laparoendoscopic Single Site Donor Nephrectomy

LDN

Laparoscopic Donor Nephrectomy

LOS

Length of Stay

ODN

Open Donor Nephrectomy

POD

Post-Operative Day