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Keywords:

  • kidney transplantation;
  • allograft;
  • warm ischaemia;
  • natural orifice transluminal endoscopic surgery;
  • NOTES

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References

Objective

  • To present outcomes of a randomized, patient-blinded controlled trial on Pfannenstiel laparoendoscopic single-site (LESS) vs conventional multiport laparoscopic live donor nephrectomy.

Patients and Methods

  • Patients presenting as left kidney donors between January 2009 and November 2011 were randomized to LESS donor nephrectomy (LESS-DN: n = 15) or conventional laparoscopic donor nephrectomy (LDN: n = 14).
  • Patients were blinded to the surgical approach preoperatively and attempts to continue patient blinding postoperatively were made by applying dressings consistent with multiple conventional laparoscopic incisions for all patients.
  • De-identified data related to the operation, peri-operative course and postoperative follow-up were prospectively collected and compared between the two groups with an intention-to-treat analysis.

Results

  • There were no significant differences between the groups when comparing operating time, estimated blood loss (EBL), i.v. fluid administration, renal allograft warm ischaemia time (WIT), length of hospital stay (LOS) and total inpatient analgesic requirements.
  • Quantitative pain assessment was not significantly different on postoperative day (POD) #0, however, it was significantly lower in the LESS-DN group, beginning on POD #1 (P < 0.05).
  • The changes in haematocrit and serum creatinine in the two groups were not significantly different, and there were no blood transfusions in either group, nor was there a decline in estimated glomerular filtration rate to <60 mL/min per 1.73 m2 of body surface area in any patients.
  • Two patients in the LESS-DN group were converted to conventional LDN, both because of failure to progress effectively.
  • All allografts were functional at the time of transplantation and revascularization, with no cases of hyperacute rejection.

Conclusions

  • Peri-operative variables including EBL, WIT and LOS were equivalent when comparing Pfannenstiel LESS-DN with conventional LDN.
  • Patient-reported visual analogue pain scale scores were significantly lower in the LESS-DN group beginning on the first postoperative day.

Abbreviations
LESS

laparoendoscopic single-site

LDN

laparoscopic donor nephrectomy

LESS-DN

LESS donor nephrectomy

EBL

estimated blood loss

WIT

warm ischaemia time

LOS

length of hospital stay

VAPS

visual analogue pain scale

POD

postoperative day

Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References

Laparoendoscopic single-site (LESS) surgery has received a great deal of attention in the last several years. As a ‘bridge’ to pure natural orifice transluminal endoscopic surgery (NOTES), LESS is a promising logical step in the progression of minimally invasive surgery. Given the reduction in the number of incisions used to perform minimally invasive procedures, it is reasonable to conclude that cosmesis is improved when using LESS techniques; however, this is further dependent upon the single-site approach used and, furthermore, may be of varying importance to different patient and operative indications [1]. Given the novelty of LESS in urological practice and the paucity of randomized controlled studies, there has been debate as to whether LESS offers any additional, tangible benefits with respect to peri-operative outcomes and convalescence.

The vast majority of data comparing LESS with conventional multiport laparoscopic surgery comes in the form of case–control studies, with limited population sizes. In most, if not all, of these studies, there has been no clear benefit to LESS with respect to peri-operative outcomes after LESS nephrectomy, pyeloplasty, adrenalectomy, sacrocolpopexy and live donor nephrectomy [2-6]. With respect to laparoscopic donor nephrectomy (LDN) vs LESS donor nephrectomy (LESS-DN), a collection of case–control studies have led to differing conclusions regarding the potential peri-operative benefits of LESS-DN, specifically with regard to convalescence [7-9]. A prospective randomized trial has been performed comparing transumbilical LESS-DN with multiport LDN, showing improved early pain relief and shorter hospital stays for LESS-DN with comparable graft function [10].

The ‘mini-Pfannenstiel’ approach to LESS-DN attempts to maximize cosmetic benefits, which may be of particular importance to potential kidney donors [11]. Given the need for an extraction incision, we posit that the umbilicus may not be the most favourable site for a 5–7-cm incision. Placed at a suprapubic position, the Pfannenstiel LESS approach can result in no visible scars when a patient is clad. To date, no randomized controlled studies have sought to determine if this approach has any benefit over traditional LDN. Moreover, no previous urological literature has attempted to blind patients to their randomization to the multiport laparoscopy or LESS approach. In the present study, we report the results of a prospective randomized, patient-blinded comparison of Pfannenstiel LESS-DN vs conventional multiport LDN.

Patients and Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References

Patient Selection and Inclusion Criteria

All patients who presented for living donor nephrectomy between January 2009 and November 2011 underwent extensive preoperative medical and psychological evaluations as per our institutional protocol. Briefly, these evaluations consistently included a standard history and physical examination, appropriate laboratory evaluation, serological assessments, and three-dimensional CT of the abdomen and pelvis with an angiographic contrast phase for detailed assessment of renal vascular anatomy and parenchymal volume for the potential allograft specimen. Multiplicity of renal vessels was not an exclusion criterion if the patient was otherwise deemed a candidate for LDN based upon anatomy. In cases of duplicated renal arteries or complex venous drainage, ex vivo reconstruction was performed by the transplant surgery team as necessary. Patients who were deemed more appropriate for right-sided donor nephrectomy, determined by relative renal function, size, nephrolithiasis or vascular configuration, were excluded from this randomized study. No other strict exclusion criteria were used.

Randomization Protocol and Data Collection

The research protocol for randomizing potential living renal donors to either multiport LDN or LESS-DN was submitted to and approved by our institutional review board. Sample size calculations using power analysis outlined an intended sample size of 40 subjects per randomized treatment arm, with an 80% power to detect a decrease in pain of ≥38% with a preset significance level α of 0.05. Patients were invited to be included in the present study at the time of counselling about the procedure involved in being a laparoscopic living renal donor. If informed consent to participate in the study was obtained, the subject was randomized by the surgical team via opaque envelope method to LPN or LESS-DN on the morning of surgery. Patients were not informed of which approach would be used before induction of general anaesthesia or after the completion of the procedure. After 3 years, the study was terminated but failed to accrue the intended number of patients for randomization.

Data were prospectively collected after patients had provided informed consent and had been officially enrolled into one of the randomized arms of the study. De-identified data on the operation, peri-operative course and postoperative follow-up for each patient were maintained in a database corresponding to the patient number assigned to each subject at the time of enrolment. The data maintained in the anaesthesia record including operating time, estimated blood loss (EBL), volume of intra-operative i.v. fluid administrationand warm ischaemia time (WIT) were assessed immediately after the culmination of the surgergy. Postoperative pain assessment using a patient-reported visual analogue pain scale (VAPS) was performed routinely by nursing staff and daily means were recorded at the end of each day, whilst the patient remained in hospital. Inpatient analgesic use was assessed via the medication administration record and all analgesics given were quantified in their equivalent value of milligrams of morphine.

Surgical Technique

Our techniques for standard multiport LDN and LESS-LDN using a Pfannenstiel approach have been previously described in detail [11, 12]. For both surgical techniques, patients were placed under general anaesthesia after appropriate i.v. access had been obtained, and a nasogastric or orogastric tube was placed for decompressive purposes. Regional anaesthesia techniques, including epidural or local nerve blocks, were not used, but the Pfannenstiel incision was routinely infiltrated with local anaesthetic by the surgical team.

Patients were placed into a modified lateral decubitus position, with all pressure points adequately padded, and secured to the operating table to allow secure rotation of the operating table towards the operating surgeon (Fig. 1). Veress needle access was obtained via the umbilicus or subcostal space, establishing pneumoperitoneum. Then, in the LDN cohort, three to four trocars were inserted as shown in Fig. 2A. For the LESS-DN cohort, a Pfannenstiel incision measuring 5–7 cm was made, through which either a GelPoint device or a series of three traditional trocars were placed within the single-site incision (Fig. 2B). In all LESS-DN cases, we used a 5-mm Olympus Deflectible-Tip EndoEYE™ laparoscope (Olympus America, Center Valley, PA, USA) which facilitated the use of two 5-mm trocars and a single 12-mm trocar. The 12-mm trocar allowed the introduction of an Multifire Endo GIA™ stapling device (Covidien, Norwalk, CT, USA) and EndoCatch bag (US Surgical Corp., Norwalk, CT, USA) for expeditious specimen removal (Fig. 3A). The endoscopist's hands were positioned in a dependent position, with downward deflection of the laparosocopic tip, providing a near ‘bird's eye view’ of the operative field, to maximize extracorporeal working space for the operating surgeon (Fig. 3B). Bariatric laparoscopic instruments were occasionally required for sufficient length to reach above and adequately free attachments to the upper pole; otherwise standard rigid laparoscopic instrumentation was used in most cases. In rare circumstances, flexible graspers and/or scissors were used to overcome the challenges of triangulation encountered during LESS cases.

figure

Figure 1. Patient positioning for left-sided LDN or LESS-DN.

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figure

Figure 2. (A) Port placement for left-sided LDN. (B) Pfannenstiel port placement for left-sided LESS-DN.

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figure

Figure 3. (A) Deflectible-tip laparoscope. (B) Use of the deflectable tip laparoscope with the endoscopist's hands in dependent position and intracorporeal scope tip deflected downward. (C) This positioning allows maximum working space for the operating surgeon.

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In both the multiport LDN and LESS-DN cases, the renal allograft specimens were extracted via a 5–7-cm Pfannenstiel incision. Patients undergoing LDN had butterfly stitches and overlying bandages placed over the 3–4 laparoscopic port-site incisions as well as over the Pfannenstiel extraction site. Patients undergoing a LESS-DN had ‘sham’ butterfly stitches and bandages placed at the umbilical, sub-xiphoid and anterior axillary line locations that had been used as trocar sites in multiport LDN cases, so as to blind the patients and patient care teams postoperatively to the surgical approach used. Postoperatively, all patients were given i.v. narcotic analgesics in the form of patient-controlled analgesia pumps or analgesia administration as required, which was changed to an oral analgesic regimen once oral intake was resumed.

Data Analysis

Continuous variables were represented as mean ± sd values and were compared across the two patient groups using Student's t-tests. Categorical variables were represented as number of observations. These variables were compared using chi-squared and Fisher exact probability testing, based upon frequency of observations. A P value of 0.05 was considered to indicate statistical significance. All statistical analyses were performed using SPSS for Windows version 16.0 (SPSS Inc., Chicago, IL, USA). Intention-to-treat analysis was performed according to patients' original randomization group, despite conversion of LESS-DN to LDN in some cases.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References

A total of 14 patients were randomized to the LDN group and 15 to the LESS-DN group. Patient demographic and preoperative data are shown in Table 1. There were no significant differences between the LDN and LESS-DN patient groups with regard to preoperative variables including sex distribution (P = 0.06), age (P = 0.95), body mass index (P = 0.85), American Society of Anesthesiologists score (P = 0.88), and multiplicity of major renal vessels (arterial, P = 0.65; venous, P = 0.48).

Table 1. Patient demographic and preoperative data
 LDNLESS-DNP
  1. Continuous variables were compared using Student's t-test and categorical variables were compared using chi-squared and Fisher's exact probability testing, based upon frequency of observations. ASA, American Society of Anesthesiologists; BMI, body mass index.

No. of patients1415-
Sex, n  0.06
Male116
Female39
Mean (sd) age, years41 ± 1141 ± 140.95
Mean (sd) BMI, kg/m227.3 ± 427.6 ± 50.85
Mean (sd) ASA score1.5 ± 0.631.5 ± 0.520.88
Arterial anatomy, n  0.65
Single1113
Multiple32
Venous anatomy, n  0.48
Single1315
Multiple10

A comparison of peri-operative variables and postoperative measures of pain and analgesic use between the two surgical approaches is shown in Table 2. There was no significant difference between the groups when comparing operating time, EBL, volume of intraoperative i.v. fluid administration and WIT. All allografts were functioning at the time of transplantation and revascularization, with no cases of hyperacute rejection. Length of hospital stay (LOS) postoperatively and total inpatient morphine equivalents administered were not significantly different when comparing the two randomized patient groups.

Table 2. Peri-operative data and measures of postoperative pain
 LDNLESS-DNP
  1. *Intraoperative serosal tear oversewn via LESS approach, resulting in prolonged postoperative ileus. Continuous variables were compared using Student's t-test and categorical variables were compared using chi-squared and Fisher's exact probability testing, based upon frequency of observations.

No. of patients1415
Mean (sd) operating time, min128 ± 28143 ± 320.21
Mean (sd) EBL, mL146 ± 77139 ± 870.80
Mean (sd) i.v. fluid, mL2807 ± 7223060 ± 7140.36
Mean (sd) WIT, min5 ± 1.15.3 ± 2.30.67
Mean (sd) LOS, days2.1 ± 0.62.4 ± 1.10.44
Mean (sd) total morphine equivalents, mg84 ± 4298 ± 1460.74
Mean (sd) change in haematocrit, %−4.4 ± 4.3−6.5 ± 4.00.18
Cases requiring transfusion, n00
Mean (sd) change in serum creatinine, mg/dL0.50 ± 0.170.56 ± 0.220.43
Conversions, n  
Standard laparoscopy2
Open surgery00
Complications, n01*1
Mean (sd) VAPS score   
POD #04.3 ± 2.74.1 ± 1.70.82
POD #13.5 ± 2.61.7 ± 1.70.04
POD #23.1 ± 2.11.2 ± 1.30.02

The mean (sd) change in haematocrit from preoperative assessment to the measurement on postoperative day (POD) #1 was −4.4 (4.3)% in the LDN group vs −6.5 (4.0)% in the LESS-DN group, P = 0.18. There were no transfusions performed in either group. The mean (sd) change in serum creatinine level between the preoperative assessment and the end of the inpatient postoperative period was 0.50 (0.17) mg/dL in the LDN group vs 0.56 (0.22) in the LESS-DN group, P = 0.43. No patients had a decline in estimated GFR to <60 mL/min per 1.73 m2 of body surface area.

Two patients in the LESS-DN group were converted to conventional LDN, both as a result of failure to progress effectively. There was only one documented complication during the study. In the LESS-DN group one patient had an intra-operative serosal tear which was immediately recognized and oversewn using the LESS approach. This patient subsequently experienced a postoperative ileus, lengthening the LOS to 5 days.

On POD #0, no significant difference was found in quantitative pain assessment between the LDN and LESS-DN groups, (mean [sd] VAPS score 4.3 [2.7] vs 4.1 [1.7], respectively, P = 0.82); however, on POD #1 and POD #2, patients in the LESS-DN group reported significantly less pain than those in the LDN group (mean [sd] VAPS score on POD #1: 1.7 [1.7] vs 3.5 [2.6], respectively, P = 0.04 and on POD #2: 1.2 [1.3] vs 3.1 [2.1], respectively, P = 0.02).

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References

Limited data exist to determine objectively what benefits, if any, the LESS surgical approach confers to patients compared with conventional laparoscopy. As with most innovations in surgical disciplines, most new techniques are introduced via small feasibility studies, followed by case–control studies, with few, if any, prospective randomized trials providing level 1 evidence to prove the advantages or disadvantages of proposed technical ‘advancements’ in the field.

Unfortunately, in the absence of level 1 evidence data, great claims about the alleged reduced morbidity of a technique, such as claims that robotic surgery is superior to laparoscopy in this respect, are often touted widely, and propagated in the form of advertisements, but these are never proven with stringent data measures in a prospective manner. In other circumstances, the magnitude of a given benefit of a new technical advance may be so large that a randomized trial is deemed to be a purely academic point such as assessment of LOS for open vs laparoscopic radical nephrectomy. In the case of LESS surgery, the potential benefits over traditional laparoscopic surgery are likely to be incrementally smaller than the step to laparoscopy from open surgery, if they exist at all. Nevertheless, this should not minimize these potential benefits, as physicians and patients alike may seek out small incremental benefits in peri-operative morbidity, convalescence or cosmesis, which LESS has been touted to offer. However, to uncover small incremental benefits between techniques, it is particularly important to pursue large-scale studies with sufficient power in a retrospective case–control setting or prospective randomized control studies to avoid bias. Attempts to blind patients and staff overseeing the postoperative care of such patients is also particularly important to further overcome observer biases, which may exist when patients undergo a cutting-edge, or state-of-the-art procedure that comes with inherent expectations of heightened success.

To that end, we sought to perform a prospective randomized controlled comparison of LDN with LESS-DN. In the literature, a previous randomized evaluation of peri-umbilical LESS-DN compared with LDN has been reported [10]. In the present study, all LESS-DN procedures were performed via a Pfannenstiel incision paralleling the extraction site we used for the LDN arm, making this the first randomized study evaluating LESS-DN performed with this single-site approach. Previous studies on surgery performed via a Pfannenstiel incision have reported this to have superior cosmetic and pain-related convalescence outcomes when compared with low-midline incisions [13, 14].

Additionally, unique to this randomized study of LESS-DN are the efforts made to blind patients and care givers in the postoperative setting to the operative technique that subjects were randomized to undergo. After consenting to participate, patients were explicitly not informed which study arm they would be randomized to, nor did peri-operative dressings or postoperative management differ across the two groups. In the two cases of converting LESS-DN to standard laparoscopy, data was interpreted with an intention-to-treat analysis along with other patients randomized to the LESS-DN group.

Reviewing the literature regarding advantages of LESS over conventional laparoscopy with respect to peri-operative outcomes and convalescence, the majority of the urological literature focuses upon renal surgery: donor nephrectomy, radical or simple nephrectomy, partial nephrectomy and pyeloplasty [15]. Of these, randomized studies have only been conducted to evaluate LESS-DN and LESS simple nephrectomy [10, 16]. Evaluation of these studies as well as other comparative studies in the literature was conducted by a recent systematic review and meta-analysis which demonstrated LESS nephrectomy to be safe and effective with some significant improvements [17]. Specifically, patients undergoing LESS-DN were found in meta-analyses to experience less postoperative pain, lower analgesic requirement, shorter convalescence and improved cosmesis.

Similarly, in the present study, we showed equivalent peri-operative parameters, including operating time, which was longer for LESS-DN in some previously reported case–control series. Although patients randomized to undergo LESS-DN were found to have significantly lower VAPS scores on POD #1 and POD #2, the total inpatient analgesic requirement was not significantly different. This discrepancy is an interesting finding; however, it does correspond directly to findings reported by Kurien et al. [10] who also compared LESS-DN with LDN in a randomized manner. In our patient population, this could potentially be explained by the protocol to provide patients with standing doses of ketorolac in addition to standard patient-controlled analgesic or an as-required analgesic regimen. The basal analgesic dosing provided by our protocol may diminish the realized differences between patient-administered or patient-prompted dosing of analgesics.

Evaluation of intra-operative conversions and peri-operative complications showed no significant difference between the two groups of patients. Rates of conversion to multiport laparoscopy (combining ‘reduced-port’ and ‘conventional laparoscopy’) has been reported in a large international, multi-institutional series to be 18.6% for LESS urological surgery overall and 21.2% specifically for LESS-DN [18]. In our series, 2/15 patients required conversion to conventional laparoscopy. No patient in the study required conversion to open surgery which is consistent with the large multi-institutional experience of 61 cases with no open conversions. Morbidity beyond the expected convalescence from the operation occurred in a single patient in the LESS-DN group, who had an inadvertent bowel serosal tear requiring intra-operative management, which resulted in a postoperative ileus and prolonged LOS compared with other patients in the same group and compared with the LDN group. Complication rates for LESS-DN have been reported as 2% for intraoperative complications and 8% for postoperative complications in the largest series reported [9, 18, 19].

Limitations of the present randomized study include the sample size. Enrolment was ended owing to slow patient accrual. In many cases, patients refused to be randomized requesting to undergo either LESS-DN or LDN when given the option. Furthermore, evaluation of the data showed no change in the convalescence measures (LOS, VAPS score and inpatient analgesic requirements) at different points of preliminary data analyses. Since intended accrual for randomization was not fully met, conclusions found can be considered as hypothesis-generating and should promote further investigation in this arena.

Another major limitation of the present study is the limited follow-up on convalescence extending beyond hospital discharge and assessing outpatient analgesic use, quality-of-life measures and time to returning to work and other routine activities. These data were not consistently available. We were also limited in allograft specimen and transplant recipient follow-up beyond initial function at the time of implantation. Follow-up of the recipient outcomes was not incorporated into our protocol of evaluating donor nephrectomy technique as the transplant recipients were not a part of the consent process for the donor's inclusion in the study.

In conclusion, in this study of randomized living renal donors, we have shown equivalent peri-operative parameters when comparing LESS-DN with LDN, including WIT, EBL and LOS. Patients in the LESS-DN group had lower in-hospital, patient-reported VAPS scores beginning on POD #1.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Conflict of Interest
  8. References
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