Francesco Porpiglia, Division of Urology, Department of Clinical and Biological Sciences, University of Turin ‘San Luigi’ Hospital, Regione Gonzole 10, 10043 Orbassano (Turin), Italy. e-mail: email@example.com
Study Type – Therapy (case series)
Level of Evidence 4
What's known on the subject? and What does the study add?
New techniques and instrumentation in laparoscopy including the use of ‘single-port’ devices and natural orifice transluminal endoscopic surgery have been proposed to reduce the invasiveness of these procedures. The introduction of small laparoscopic instruments (<3 mm) continues to further the field. To date, mini-laparoscopic instruments have been used in many urological procedures, e.g. pyeloplasty in the paediatric population. However, data of pure mini-laparoscopic pyeloplasty (mLP) for the treatment of pelvi-ureteric junction obstruction in the adult population are lacking.
In a selected adult population mLP is feasible and safe. Perioperative and 1-year functional results are comparable with those of standard LP, while cosmetic results of mLP are more appreciated by the patients.
• To evaluate perioperative and cosmetic results after pure mini-laparoscopic pyeloplasty (mLP) compared with standard LP (sLP) in an adult population.
PATIENTS AND METHODS
• From April 2009 to June 2010, 12 patients underwent mLP for pelvi-ureteric junction (PUJ) obstruction (PUJO). For comparison, 24 patients that had previously undergone sLP were pooled from our institutional database.
• All patients were assessed preoperatively with physical examination, abdominal ultrasonography, intravenous urography or computed tomography and renal scintigraphy (RS). In all cases, an Anderson-Hynes transperitoneal approach was used.
• After surgery, cosmetic results were assessed using a Patient Scar Assessment Questionnaire (PSAQ), and RS measured reconstructive success at 1-year after LP.
• Demographic and perioperative variables were recorded. Groups were compared using chi-squared and Wilcoxon-Mann-Whitney tests (P < 0.05 was considered significant).
• Baseline characteristics were similar between the groups. There were no differences in operative duration or blood loss. One mLP required conversion to sLP due to minor bleeding.
• Analgesic consumption and the pain visual analogue scale scores were not significantly different between the sLP and mLP cohorts.
• The average postoperative hospital stay for the mLP group was significantly shorter than that for the sLP group (P= 0.024).
• Complication and success rates between the groups were not significantly different.
• PSAQ scores showed that mLP patients were significantly more satisfied with their cosmetic result.
• mLP appears to be safe, feasible and effective in the treatment of PUJOs.
Due to reduced morbidity and shorter hospital stays, laparoscopy has largely replaced open surgery for the treatment of many urological diseases [1,2]. Refinement of technique and instrumentation has continually reduced the invasiveness of laparoscopic surgery since its inception. With this aim, new techniques in laparoscopy including the use of ‘single-port’ devices and natural orifice transluminal endoscopic surgery have been studied [3–6]. The introduction of smaller laparoscopic instruments (≤3 mm) continues to further the field. The 2- and 3-mm ports are virtually incision less and do not require suturing upon closure. The end result for the patient is essentially a ‘scarless’ incision. Moreover, many consider that 2- or 3-mm incisions rather than 5- or 10-mm incisions reduce pain and translate to shorter hospital stays, faster recovery, and diminished wound morbidity. To date, mini-laparoscopic instruments have been used in many urological procedures, including renal cyst decortication, orchidopexy, lymphocele marsupialisation, pelvic lymph node dissection and adrenalectomy [3,7,8].
Since it was first described, the laparoscopic pyeloplasty (LP) has gained popularity for the treatment of PUJ obstruction (PUJO). In fact, several studies have reported equivalent success using laparoscopic vs open techniques [9–11]. However, due to the well-established advantages of minimal invasive surgery, LP has become the first choice for the treatment of PUJO at many advanced laparoscopic centres. Efforts to further reduce invasiveness have resulted in laparoendoscopic single-site (LESS) surgery [12–14]. However, the role of pure mini-LP (mLP; 3-mm instruments) in this setting is relatively unexplored in adult population [14,15].
The aim of the present study was to analyse the perioperative outcomes and cosmetic results of pure mLP in an adult population compared with standard LP (sLP).
PATIENTS AND METHODS
From April 2009 to June 2010, 12 patients underwent mLP for PUJO. Inclusion criteria were as follows: age > 18 years, body mass index (BMI) < 25 kg/m2, no history of major abdominal surgery, a primary PUJO, and no previous surgery on the affected kidney. This series of patients represents our first experience with this technique.
Patients undergoing mLP were compared with 24 (2:1) matched patients undergoing sLP. Comparison patients were taken from our prospectively maintained, Institutional Review Board-approved database of LP procedures performed before October 2005. Matching criteria included gender, age, BMI, and clinical history (primary PUJO, no previous major abdominal or ipsilateral renal surgery).
All patients in both groups were preoperatively assessed with physical examination, abdominal ultrasonography, IVU or CT and renal scintigraphy (RS).
In all cases, an Anderson-Hynes LP using a transperitoneal approach was performed by the same surgeon (F.P.). Under general anaesthesia, the patient was placed in a 45 ° lateral decubitus position, and a pneumoperitoneum was achieved using a Veress needle at the level of the umbilicus. An intra-abdominal pressure of 12–14 mmHg was maintained.
Depending on the patient's body habitus, the initial port (3.9 mm) was placed at or 2 cm lateral to the umbilicus. A 3-mm 30 ° miniature scope was then inserted through the initial port. For procedures on the left renal pelvis, two mini ports were placed under direct vision along the left midclavicular line. When possible in the case of a left PUJO, a transmesocolic approach was used as previously described . In other cases, a standard colon retracting approach was used. For right-sided PUJOs, two mini ports were placed along the right midclavicular line and a fourth port was placed below the xiphoid for the purpose of liver retraction (Fig. 1). The PUJ was reached via an incision in the posterior peritoneum and, if necessary, via a colonic hepatic flexure-reflecting approach.
After resection of the PUJ, suspension of the renal pelvis from the abdominal wall using a straight needle facilitated pelvi-ureteric anastomosis. The posterior portion of the anastomosis was made using a running 5-0 monofilament suture with a 4/8 round needle that was inserted through the mini port. Then, a 6 F JJ ureteric stent was placed over a guidewire and inserted in a retrograde fashion using flexible pneumocystoscopy, as previously described . The anterior portion of the anastomosis was made with a separate running suture. Upon completion of the procedure a 12 F intraperitoneal drain was placed through the umbilical port. All 3.9-mm ports and 3-mm instruments were manufactured by Karl Storz® (Tuttlingen, Germany).
A 12-mm port was placed at or 2 cm lateral to the umbilicus. A 10-mm 30 ° scope was then used to visualize subsequent port placements. In cases of left PUJOs, a 12-mm port (for 5–10 mm instruments) and a 7-mm port (for 5 mm instruments) were placed along the left midclavicular line. When possible, a transmesocolic approach was used. In cases of right PUJOs, two ports (7 and 12 mm) were placed along the right midclavicular line, and a fourth port (5 mm) was placed below the xiphoid for liver retraction. All other steps were performed as described above. Hem-o-Lok® clips were used to ensure haemostasis when necessary.
Apart from the demographic variables we recorded operative duration, blood loss, perioperative complications according to the Clavien-Dindo system , day of catheter removal, pain visual analogue scale (VAS) score and use of analgesics (1 g i.v. paracetamol in vials) for all patients. We recorded only those pain medications required ≥24 h after the procedure. Early postoperative analgesic therapy (<24 h after surgery) that was prescribed by the anaesthesiologist was not considered. Patients were then followed, and length of postoperative hospital stay was recorded.
To evaluate cosmetic results, the Patient Scar Assessment Questionnaire (PSAQ) , a standard scoring system developed for plastic and reconstructive surgery, was administered to all mLP patients 3 months after mLP. Because the scoring system was not readily available at the time of surgery for the sLP group, the PSAQ was administered during control visits at time points >3 months after surgery.
RS was performed 12 months after surgery. The parameters used to determine reconstructive success were clinical resolution of symptoms and radiographic evidence of T1/2 < 20 min on RS .
Groups were compared using chi-squared and Wilcoxon-Mann-Whitney tests for categorical and continuous variables, respectively. Statistical significance was set at P < 0.05. All reported P-values were two-sided.
Baseline characteristics between the two groups, including age, gender, American Society of Anesthesiologists score, side of procedure and BMI, were similar (Table 1).
Table 1. (a) Baseline characteristics of patients and (b) Perioperative and functional results
ASA, American Society of Anesthesiologists; PU, pelvi-ureteric; POD, postoperative day.
(a) Demographic data
Total number of patents
Female, n/N or n (%)
Male, n/N or n (%)
Mean (sd) age, years
Mean (sd) BMI, kg/m2
Median (range) ASA score
Left sided, n/N or n (%)
Right sided, n/N or n (%)
Crossing vessels, n (%)
Significant hydronephrosis (>grade II) at preoperative CT or IVU, n/N or n (%)
Flank pain or renal colic, n/N or n (%)
Recurrent UTI, no. (%)
Patients with significant comorbidities, n/N or n (%)
(b) Perioperative and functional results
Operative duration, min
Time to complete PU suture, min
Blood loss, mL
n/N or n (%):
Transmesocolic approach on the left side
Conversion to hybrid procedure
Conversion to open procedure
VAS score POD 1 to the discharge
Paracetamol, vials per patient
Catheter removal, days
Postoperative hospital stay, days
JJ-stent removal, days
n/N or n (%):
Significant hydronephrosis (> grade II) at 6-month CT (or IVU)
T1/2 < 20′ at renal scintigraphy
Pain relief after intervention in symptomatic patients (%)
Recurrent UTI after surgery
Perioperative outcomes are summarised in Table 2. There were no differences in operative duration or blood loss. There was one mLP case (one of 12) that required conversion to sLP due to minor bleeding that could not be controlled with bipolar forceps. In this case, a 3.9-mm port was exchanged with a 12-mm port such that a suction device and Hem-o-Lok applier could be used. There were no major intraoperative complications and no conversions to open procedures were required in the two groups. Analgesic consumption and the pain VAS score were not significantly different between the sLP and mLP cohorts. The average postoperative hospital stay was significantly shorter for the mLP group compared with the sLP group (P= 0.024, Table 2).
Table 2. Cosmetic results
Cosmetic results, mean (sd)
Satisfaction with appearance
Satisfaction with symptoms
In the mLP group, two of 12 patients had postoperative complications. One individual had a grade I complication according to the Clavien system , a fever treated by antibiotic therapy. The other patient had a grade III complication, a urine leak with collection in the surgical drain and a percutaneous nephrostomy tube was placed. In the sLP group, five of 24 patients (20.8%) had postoperative complications. There were three cases (12.5%) of grade I/II complications (two fevers treated by antibiotic therapy and one serum haemoglobin drop treated by blood transfusion) and two (8.3%) cases of grade III complications: urine leak requiring percutaneous nephrostomy tube placement and gross haematuria requiring percutaneous clot irrigation of the renal pelvis.
No grade > IIIa complications were recorded, and no differences were recorded for overall (P= 0.766) or severe (>grade II, P= 1.000) complications between the two groups.
The PSAQ scores showed that patients who received mLPs were significantly more satisfied with their cosmetic result than those who had sLPs. This was true both for overall and subscale scores (Table 2, Figs 1 and 2).
All patients but one in the mLP group (11/12) had a T1/2 < 20 min on RS performed 1 year after surgery . In addition, all symptomatic patients had clinical resolution of symptoms with a success rate at 1 year postoperatively of 11/12 mLP patients. In the sLP group, all patients but one (23/24; 95.8%) had a T1/2 < 20 min on RS and clinical resolution of symptoms. No significant differences were recorded between the groups in terms of success rates (P= 0.609).
LP was first proposed by Schuessler et al.  in 1993. Due to its favourable result profile and the well-known advantages of minimally invasive surgery, it has become the first choice for the treatment of PUJOs at many centres. To further reduce the invasiveness of such procedures, some authors have proposed the LESS pyeloplasty. To date, most authors have concluded that LESS pyeloplasty is feasible, safe and perioperative outcomes are similar to those of conventional LPs [11–13]. However, cosmetic results of mini-laparoscopic procedures were often not considered or were investigated in a non-standardised way [21–24]. The main drawback of the LESS procedure seems to be the loss of triangulation – the basic rule of laparoscopy. The clashing of instruments, use of additional ports (one or more), and use of articulating instruments make this procedure's learning curve steep.
Miniaturisation of laparoscopic instruments (≤3 mm) has not only reduced the invasiveness of procedures but has also given way to ‘mini-laparoscopic’ surgery. Although previously reserved for diagnostic purposes only, mini-laparoscopic techniques are increasingly used for therapeutic procedures in urology including adrenalectomies, nephrectomies, renal cyst marsupialisations and orchidopexies [3,7,8]. Because reconstructive procedures do not require extraction of a surgical specimen, an increasing number of these may be completed using mini-laparoscopy to reduce surgical scarring. mLP has been proposed in the paediatric population; however, data regarding mLP in the adult population are lacking to date .
Based on the these considerations coupled with our previous LP experience and encouraging experience with mini-laparoscopy , we chose to conduct the current case-control study comparing mLP and sLP performed by one surgeon at a single institution. To ensure patient safely while developing this novel approach, we instituted several inclusion criteria. These included patients that were not obese without previous significant abdominal or renal surgery. The matched-paired analysis allowed us to compare two homogeneous groups. In fact, there were no differences in demographic variables (Table 1).
A transperitoneal approach was used for both the mLPs and sLPs included in the present study. Compared with a retroperitoneoscopic approach, this approach allowed us to increase our operative field and better manage renal abnormalities (e.g. malrotation and crossing vessels) . mLP allows for all traditional steps of a pyeloplasty without losing triangulation and without the use of flexible instruments or special tools.
The results of the present study confirm that mLP is safe in a select adult population. In the present study, mLP operative durations were similar to those of sLPs. Interestingly, this finding is in contrast to previous reports in which the mean operative duration for mini-laparoscopy was ≈20% longer than the standard laparoscopic procedure . Postoperative outcomes including analgesic consumption and pain VAS score were not significantly different between the sLP and mLP cohorts. The average postoperative hospital stay for the mLP group was significantly less than that of the sLP group (P= 0.024), suggesting that mini-laparoscopy could improve postoperative outcomes. In one case, the mLP was converted to a hybrid procedure, which included all 3.9-mm ports except for one, due to minor bleeding that could not be controlled with bipolar forceps. In this case, a 12-mm port was used at the level of umbilicus, and the 3-mm scope was switched to the lateral 3.9-mm port such that it was in the surgeon's right hand. This allowed for the use of standard bipolar forceps, a suction device and the introduction of a 10-mm Hem-o-Lok applier through the 12-mm port. The procedure was completed without further problems. There was one major (>II according to the Clavien System) complication in the mLP group and two in the sLP group (P= 1.000). All applicable complications were managed with a percutaneous approach and did not require re-intervention. The complication rates of both groups in the present study were comparable to published rates for sLP and LESS pyeloplasty [10–16,20].
The PSAQ scores showed a statistically significant advantage for cosmetic results in the mLP group. The fact that the questionnaire was completed after >3 months after surgery by the sLP group (vs ≤3 months after surgery by the mLP group) is potentially a source of bias. However, to our knowledge, few reports have been published with standardised comparisons between mLPs and sLPs. In fact, most studies compare the broad categories of minimally invasive procedures (mini-laparoscopy, LESS) to standard laparoscopic procedures.
Although functional success was not the primary endpoint of the present study, success rates at 1-year functional follow-up for our populations were 11/12 and 23/24 (95.8%) in the mLP and sLP groups, respectively (P= 0.609). These are comparable to published success rates for sLP and LESS [11–13]. Dismembered pyeloplasty success rates range from 90–95% [25–27].
The mini-laparoscopic approach undoubtedly has disadvantages. The image quality provided by the 3-mm scope is not ideal during active bleeding, even if minor, as it causes light absorption and decreases image quality. The suction cannula has poor flow and sometimes fails to maintain a clear surgical field. Furthermore, due to port size limitations, mini-laparoscopic clips and Hem-o-Lok applicators are unavailable. For these reasons, bleeding should be prevented during the preliminary phases of the intervention by exercising meticulous dissection technique around the PUJ. Even if the principles of laparoscopic surgery are respected, no special instruments are needed, and the learning curve for mLP is acceptable, we think that significant laparoscopic experience is required before attempting mLP.
The present study has the following limitations. First, retrospective case-control studies allow for the introduction of confounding variables, selection bias and information bias. Nevertheless, the reader should note that our retrospective data are based on a prospectively maintained database, which should reduce biases. Secondly, the present study is limited by a small sample size and selective enrolment, including certain favourable characteristics, e.g. primary PUJOs, normal BMIs and no previous major abdominal surgeries. Moreover, women mainly composed the population studied: this could have overemphasised the importance placed upon cosmesis. As a result, this report may not accurately represent the general public. Also, concerning the shorter postoperative hospital stays we observed in mLP cohort, the urological staff could have been pushing for quicker discharge for the patients who underwent mLP. Finally, even if satisfaction with cosmetic results was recorded in a standardised fashion, there could have been another bias as the patients who were undergoing mLP were told they were getting a ‘special’ mini-invasive approach with (potentially) excellent cosmesis.
Notwithstanding these limits, the present results show that mLP is safe and effective for the treatment of PUJOs. This approach has improved postoperative outcomes vs sLP such as significantly reduced postoperative hospital stays. Cosmetically, patients in the mLP were significantly more satisfied with their results. We think that this technique, among other minimally invasive options, can play an important roll toward ‘scarless’ surgery. Further studies with a larger sample size are required to confirm the present data. We hope that further studies can also determine the advantage, if any, of this procedure over standard laparoscopy or techniques such as LESS.