Laparoendoscopic Single-site Adrenalectomy Research Articles

Comparison of Laparoendoscopic Single-Site Adrenalectomy with the Aid of Intracavitary Retractors and Multiport Laparoendoscopic Adrenalectomy.

Objective: To evaluate the operative outcome of the use of intracavitary retractors in transumbilical laparoendoscopic single-site (LESS) adrenalectomy in comparison with the conventional multiport laparoendoscopic procedure. Methods: Between July 2021 and December 2023, 34 patients underwent transumbilical LESS adrenalectomy with intracavitary retractors, while 47 patients underwent conventional multiport laparoscopic adrenalectomy. Comprehensive data were compared, including demographics, intraoperative outcomes, perioperative complications, postoperative visual analog pain scale score, analgesic requirement, and short-term measures of convalescence. Results: Baseline characteristics were similar between the groups. All procedures were successfully completed without additional access or open conversion. The mean operative time and estimated blood loss for LESS adrenalectomy were comparable with multiport adrenalectomy. The LESS group had significantly shorter incision length (3.07 cm versus 5.16 cm, P < .01), lower postoperative pain scores (3.29 versus 4.91, P < .01), less analgesic drug use (29% versus 53%, P = .03), and better cosmetic scores (9.29 versus 7.28, P < .01). No significant differences were observed in time to resume oral intake, time to ambulation, or postoperative hospital stay. Complication rates were similar between the groups. Conclusion: The utilization of intracavitary retractors in transumbilical LESS adrenalectomy has demonstrated feasibility, effectiveness, and the potential to reduce technical complexities with satisfactory cosmetic effects. This technique enhances visualization of the surgical field without the need for extra ports.

Comparison of Chief Surgeons' and Assistants' Feelings of Fatigue Between Laparoendoscopic Single-site and Conventional Laparoscopic Adrenalectomy.

Our objective was to compare the surgical staff's feelings of fatigue between laparoendoscopic single-site adrenalectomy (LESS-A) and conventional laparoscopic adrenalectomy (CLA) before and after surgery. Data were collected for surgical procedures performed between June 2011 and September 2017 (57 LESS-A and 37 CLA). Each procedure in both groups was performed by the same chief surgeon. The subjective fatigue feelings of the key members of the surgical team (chief surgeon, scopist, assistant surgeon) were assessed using the "Jikaku-sho shirabe" questionnaire, which contained questions about work-related feelings of fatigue. It consisted of 25 subjective items for 5 factors drawn from factor analysis (drowsiness, instability, uneasiness, local pain or dullness, and eyestrain). For each item, the participants were requested to estimate the intensity of their feelings using a five-point rating scale before and after surgery. There was no significant difference in operative time (p = 0.231) between the LESS-A and CLA procedure groups. For the chief surgeon, local pain or dullness (p = 0.603) and eyestrain (p = 0.086) were similar between the LESS-A and CLA procedures. The scopists and assistant surgeons in the LESS-A group did not suffer local pain or dullness (p = 0.793 and p = 0.240, respectively). They did, however, suffer more eyestrain than those in the CLA group (p = 0.001 and p = 0.001, respectively). Although LESS-A is generally considered to be a technically difficult procedure, the results of this study demonstrate that the feelings of physical fatigue are roughly equivalent between LESS-A and CLA procedures.

582 - Clinical usefulness of preoperative computed tomography parameters to predict the surgical outcomes of laparoendoscopic single-site adrenalectomy

582 - Clinical usefulness of preoperative computed tomography parameters to predict the surgical outcomes of laparoendoscopic single-site adrenalectomy

Effect of preoperative computed tomography parameters and obesity on surgical outcomes of laparoendoscopic single-site adrenalectomy.

The aims of the present study were to (1) analyse preoperative computed tomography (CT) parameters, (2) investigate whether obesity and CT parameters affect surgical outcomes in patients undergoing LESS lateral retroperitoneal adrenalectomy, and (3) further establish the optimal cutoff point of CT parameters for tolerable operating time. Between January 2010 and August 2016, patients who underwent LESS adrenalectomy through the retroperitoneal approach in our hospitals were included. Patients' demographic data, preoperatively measured CT parameters (the depth and horizontal width to the adrenal gland in the axial view of abdominal CT, the vertical height in the coronal view of CT, and the angle of the depth and horizontal width), and intraoperative (operative time and blood loss) and postoperative (hospital stay and complications) parameters were retrospectively reviewed. Linear regression was performed to determine factors that potentially affect surgical outcomes. In 116 patients, depth was the only CT parameter associated with surgical outcomes. Large depth (P = 0.005; 95% CI 1.739-9.256) and high BMI (P = 0.012; 95% CI 0.357-2.851) were factors significantly associated with longer operative time. The area under the ROC curve for the depth was 0.69 (P = 0.002), and the cutoff point 10.48cm may be the tolerable operating time. Our results suggest a depth limit of 10.48cm for the optimal prediction of operating time less than 90min; although obese patients and deeper adrenal glands had longer operative time, LESS adrenalectomy could be performed in the obese patients without increased blood loss, prolonged hospital stay, or increased pain.

Transumbilical laparoendoscopic single-site adrenalectomy: A feasible and safe alternative to standard laparoscopy

Standard multi-port laparoscopic adrenalectomy (LA) is considered the gold standard for benign adrenal tumors. Single-site LA has been proposed as a feasible and safe alternative because of lower invasiveness, improved cosmetics, less pain and shorter hospital stay. The objective was to evaluate and compare results of single-site transumbilical laparoendoscopic adrenalectomy with standard LA for adrenal tumors. One hundred consecutive adrenalectomies from 93 patients, performed between March 2009 and June 2017, were laparoscopically excised: 59 by standard multi-port LA (group 1) and 41 by transumbilical laparoendoscopic single-site adrenalectomy (group 2). Data gathered included demographics, comorbidities, preoperative imaging, tumor characteristics, perioperative data, surgical complications, pathology and follow-up. IBM SPSS Statistics 23 software was used and p value < 0.05 was considered significant. Patients of group 2 were younger (48.7 ± 13.9 versus 59.7 ± 15.1 years; p < 0.001) and had fewer comorbidities (p < 0.05). Mean tumor diameter in group 2 was lower than those of group 1 (27.52 ± 14.3 versus 47.9 ± 30.6 mm; p < 0.001). Tumor laterality did not influence the choice of technique nor the surgical morbidity. All procedures were successfully completed, although one standard LA needed conversion to open surgery. Mean operative time, hemorrhagic losses, postoperative opioid analgesic requirement and hospital stay were not statistically different between groups. Most patients in group 2 (31 patients, 85.4%) did not require drainage, compared to 14 (25.4%) patients of group 1 (p < 0.001). Patients who underwent single-site LA resumed normal diet earlier (1.0 ± 0.2 versus 1.6 ± 0.7 days; p < 0.001). There were no reoperations and no perioperative mortality. Overall mean follow-up time was 94.9 ± 3.1 months, not statiscally different between groups (p = 0.7). Our results revealed that transumbilical approach for laparoendoscopic single-site adrenalectomy for adrenal tumors is a feasible and safe alternative to standard laparoscopic adrenalectomy.

Longitudinal analysis of laparoendoscopic single-site adrenalectomy and conventional laparoscopic adrenalectomy regarding patient-reported satisfaction and cosmesis outcomes

To compare longitudinal patient-reported cosmesis of laparoendoscopic single-site adrenalectomy (LESS-A) to that of conventional laparoscopic adrenalectomy (CLA). A total of 23, 15, and 9 patients underwent transumbilical LESS-A (TU-LESS), subcostal LESS-A (SC-LESS), and CLA, respectively. A questionnaire was administered asking the patient to assess wound pain (0: not painful to 10: very painful), satisfaction (0: not satisfied to 10: very satisfied), and cosmesis (0: very ugly to 10: very beautiful) on the basis of a visual analogue scale. We mailed questionnaires to all patients who received LESS-A and CLA at postoperative 1, 3, 6, 9, and 12 months. No significant differences were observed in the pain scores between TU-LESS, SC-LESS, and CLA at every time point. In the CLA group, the cosmesis and satisfaction scores were significantly lower at postoperative 3 months (p=0.0033, 0.0130). There were no significant inter-group differences in the cosmesis score between the three groups after postoperative 6 months. However, the satisfaction score of SC-LESS decreased after postoperative 3 months and was significantly lower at postoperative 9 and 12 months (p=0.0333, 0.0160). The difference between the satisfaction scores of each procedure gradually increased after postoperative 6 months. This study is the first comprehensive longitudinal analysis of patient-reported satisfaction and cosmesis outcomes between LESS-A and CLA. The resulting data provide important insights into the improvement in satisfaction in patients who underwent TU-LESS. These findings can facilitate the treatment decision-making process for patients who are considering laparoscopic adrenalectomy.

Clinical Usefulness of a Self-Retaining Internal Organ Retractor for Laparoendoscopic Single-Site Adrenalectomy.

Although laparoendoscopic single-site adrenalectomy (LESS-A) is feasible, it is still considered as a challenging procedure because of technical limitations. Making an optimal retraction is one of major obstacles in LESS-A, and it sometimes requires additional ports or needlescopic devices. Internal organ retractor (IOR) is a novel retraction device that is applied intracorporeally without additional port. In this study, we investigated the clinical usefulness of IOR in LESS-A. Medical records of 73 consecutive patients who underwent LESS-A from March 2009 to December 2014 were reviewed. Twenty-two patients underwent LESS-A with IOR and 51 patients without IOR. Mean age, body mass index, tumor size, operation time, estimated blood loss, and hospital stay were not significantly different between two groups. In IOR group, median number of applied IOR was 2.0 (1.0-3.0) per single operation. Mean time for application and removal was 80.0 and 46.5 seconds for a single IOR, respectively. There were no complications related to the IOR. In without IOR group, there were nine cases that needed needlescopic trocars, six cases that needed 5 mm or larger trocars, and one case that was converted to hand-assisted laparoscopy. However, we did not use any needlescopic instrument or additional trocar in IOR group. There was no case of open conversion in both groups. LESS-A could be done effectively and safely using IOR. IOR system maintained optimal retraction throughout the operation. Its application and removal are intuitive and take only a few minutes. We think IOR system is an attractive retraction method in LESS-A.

Comparisons of surgeons’ and assistants’ fatigue after laparoendoscopic single-site versus conventional laparoscopic adrenalectomy: A single surgeon’s experience

Comparisons of surgeons’ and assistants’ fatigue after laparoendoscopic single-site versus conventional laparoscopic adrenalectomy: A single surgeon’s experience

A Single-Institution Experience with Laparoendoscopic Single-Site Retroperitoneal Adrenalectomy

Aims: Laparoendoscopic single-site (LESS) adrenalectomy has become a feasible choice for adrenal lesions and can substitute for conventional open adrenalectomy. This report shares our surgical experience and describes the characteristics of adrenal tumors after LESS retroperitoneal adrenalectomy. Subjects and Methods: Between January 2010 and August 2016, 123 patients underwent an LESS adrenalectomy by retroperitoneal approach in our hospital. We retrospectively reviewed the records of these patients and analyzed the characteristics of adrenal tumors. The incision is below the 12th rib in the posterior axillary line and is about 2.3–3.2 cm in length. A 5 mm 30° rigid laparoscope and other conventional laparoscopic instruments are manipulated through a commercial port. No postoperative drain is placed. Results: Among 123 patients, the mean operative time was 114.1 ± 31.1 min, and mean blood loss was 65.1 ± 68.7 ml. Mean hospital stay was 5.4 ± 1.2 days. The postoperative course was uneventful without complications. Among all adrenal tumors undergoing surgery, Conn's disease is the most common (68.3% Conn's disease, 19.5% nonfunctioning, 4.9% Cushing's disease, 3.3% pheochromocytoma, and 0.8% malignancy). We found that left-side adrenal tumors (64.2%) were more common than right-side tumors (35.8%). Conclusions: Our experience shows that retroperitoneal LESS adrenalectomy is promising. Conn's disease accounts for more than half of adrenal tumors undergoing surgery. In the future, further comparative study is warranted to define the role of LESS in adrenal surgery.

Factors affecting operative efficiency and post-operative convalescence in laparoendoscopic single-site (LESS) adrenalectomy.

Laparoendoscopic single-site (LESS) adrenalectomy is a novel challenging technique which is still under clinical evaluation. Initial reports have revealed its superiority in patient convalescence. In addition, it has been reported that some patient or anatomic factors might affect the ergonomics of LESS adrenalectomy. The aim of this study is to investigate the possible factors that might affect procedural efficiency and patient convalescence in LESS adrenalectomy. Between October 2009 and July 2015, 105 consecutive adult patients with benign adrenal tumors, who underwent LESS retroperitoneal adrenalectomy were enrolled in this study. All the relevant peri-operative parameters were prospectively collected for later analysis. By using stepwise linear regression and stepwise selection of these peri-operative parameters, those that might affect the operative efficiency and patient convalescence were analyzed. Finally, 78 patients who completed follow-up and were eligible for stepwise linear regression were enrolled for final analysis. For parameters affecting operative efficiency, the fitted model revealed that patients with a pre-operative diagnosis of pheochromocytoma, a higher BMI, and an associated co-morbidity of heart disease are associated with a longer operative time. In addition, the fitted model revealed that patients with a lower post-operative pain score, a delayed oral intake, and a diagnosis of non-functioning adrenal tumor were associated with a lengthier period before returning to normal activity. A higher BMI is the only anatomic factor that affects procedural efficiency in LESS adrenalectomy. In addition, post-operative pain score, time to oral intake, and a diagnosis of non-functioning adrenal tumor are the factors affecting patient convalescence.

Patient-reported postoperative pain, body image, and cosmetic satisfaction after transumbilical laparoendoscopic single-site adrenalectomy.

Laparoendoscopic single-site surgery is a recently innovated urologic surgical procedure. Transumbilical laparoendoscopic single-site adrenalectomy (LESS-A) is technically safe and feasible in patients with benign adrenal tumors. To improve patient counseling and informed consent, we evaluated patient-reported postoperative pain, body image, and cosmetic satisfaction after transumbilical LESS-A. We reviewed 24 patients who underwent transumbilical LESS-A and assessed their operative and esthetic outcomes and incisional pain. Incisional pain was evaluated using a 10-point visual analog scale, and the body image and cosmetic satisfaction were measured using a questionnaire that included a body image scale (range, 5-20 points) and a cosmetic scale (range, 3-24 points). Pure LESS-A was performed on 10 patients using a multichannel port; an additional 5-mm trocar was used in two obese patients. Supplementary to the single-incision approach, one or two 3-mm ports were used in 12 patients. The mean operative time was 203min; the mean blood loss was 41mL. The mean pain visual analog scale scores on postoperative days 1, 3, and 7 were 3.5, 2.2 (P=0.012), and 1.5 points (P=0.018), respectively. The mean body image scale and cosmetic scale scores indicating wound satisfaction 1month after the surgery were 20 and 22 points, respectively. Although one patient had liver injury during surgery, the postoperative course during the 3-month follow-up was uneventful. Transumbilical LESS-A confers less postoperative pain and better cosmetic satisfaction than conventional laparoscopic adrenalectomy. Therefore, this procedure could potentially become a standard treatment option for benign adrenal tumors.

The learning curve of laparoendoscopic single-site adrenalectomy: an analysis of over 100 cases.

Recently, laparoendoscopic single-site adrenalectomy (LESS-A) has been developed as an alternative treatment for adrenal tumors. Although LESS-A is more technically complex than conventional laparoscopic adrenalectomy, its learning curve and the factors associated with poor surgical outcomes are poorly understood. We analyzed the learning curve of LESS-A and attempted to identify risk factors associated with worse surgical outcomes. We identified 103 patients who underwent LESS-A [performed by the same surgeon (A.M.)] from 2009 to 2015. The learning curve was analyzed using the moving average method (the 10-case moving average), and we assessed potential risk factors for a prolonged pneumoperitoneum time. The learning curve stabilized at 30 cases. The cases were divided into two groups, the learning stage (LS) (cases 1-29) and master stage (MS) (cases 30-103) groups. The percentage of females and the frequency of previous abdominal surgery were higher in the LS group (p=0.022 and 0.001, respectively). In the LS group, the mean pneumoperitoneum time was 92±35min, which was significantly longer than the equivalent value for the MS group (55±18min, p<0.001). In the LS group, univariate analysis revealed that tumor size (≥50mm) and the visceral fat area (VFA)/total fat area (TFA) ratio (≥0.49) were significantly associated with a prolonged pneumoperitoneum time (p=0.046 and 0.046, respectively). In the multivariate analysis, tumor size and the VFA/TFA ratio were confirmed to be associated with a prolonged pneumoperitoneum time (p=0.029 and 0.029, odds ratio 20.83 and 20.83, respectively). On the other hand, none of the examined factors were found to be associated with a prolonged pneumoperitoneum time in the MS group. LESS-A was performed safely in most cases. However, surgeons who are learning the LESS-A procedure need to pay attention to tumor size and visceral obesity.

Laparoendoscopic Single-site Adrenalectomy versus Conventional Laparoscopic Adrenalectomy: An Updated Meta Analysis.

Previous meta-analyses that compared the outcome of laparoendoscopic single-site adrenalectomy (LESSA) and conventional laparoscopic adrenalectomy (CLA) have not shown consistent results. The aim of this meta-analysis was to reassess current evidence regarding the efficacy and safety of LESSA versus CLA. A literature search of PubMed, Embase, Medline, and the Cochrane Library was performed to identify eligible articles up until September 2015. Quantitative variables were calculated using the weighted mean differences (WMDs), and qualitative variables were pooled using odds ratios (ORs). Ten retrospective studies, including a total of 704 cases, were identified. Patients in the LESSA group benefitted from shorter length of hospital stay (95% confidence interval [CI]: -1.27 to -0.36, WMD: -0.81, P < .001) and better postoperative pain scores (95% CI: -1.51 to -0.99, WMD: 1.25, P < .001). There was no significant difference between the two techniques in operative time, estimated blood loss, resumption of oral intake, dose of analgesic required, perioperative complications, conversion, transfusion, or pain medications required. Based on current evidence, LESSA appear to be a safe and feasible alternative to CLA with a shorter length of hospital stay and lower postoperative pain scores in certain patients. We await high-quality, double-blind randomized clinical trials with long-term follow-up to confirm and update the findings of this analysis; future studies should focus on failure of technique, cosmesis, and cost.

Is Laparoendoscopic Single-Site Adrenalectomy a Feasible Alternative in Treating Aldosterone-Producing Adenoma?

Objective. To compare laparoendoscopic single-site (LESS) and conventional multiport adrenalectomy in patients with aldosterone-producing adenoma (APA). Material and Methods. We retrospectively reviewed patients who had been clinically confirmed with unilateral APA and who underwent LESS or multiport adrenalectomy between 2009 and 2014. Perioperative data were obtained for all patients. Blood pressure and the levels of serum aldosterone, renin, and potassium were checked periodically. Results. We identified 45 APA patients in the LESS group and 71 in the multiport group. The baseline characteristics were matched between two groups. All adrenalectomies were completed successfully, except one with laparoscopic conversion in the single-port group and one open conversion in the multiport group. After a mean follow-up around one year, there were no significant group differences in the improvement of hypertension, number of types of medication taken, and cure of hypokalemia after operation. Conclusions. Our study confirm that LESS adrenalectomy achieved similar clinical and functional outcomes as conventional multiport adrenalectomy for management of unilateral APA.

Laparoendoscopic single-site adrenalectomy in patients with primary hyperaldosteronism: A prospective study with long-term follow up

Laparoendoscopic single-site (LESS) adrenalectomy is a promising minimally invasive technique, however, the current evidence has not confirmed its long-term effectiveness in primary aldosteronism (PA). We conducted a study to analyze the long-term efficacy of LESS adrenalectomy in patients with PA. A total of 49 patients who had been clinically confirmed with PA who had an indication for unilateral adrenalectomy were included in this study. Perioperative data were obtained for all patients. Blood pressure and the levels of serum aldosterone, renin, and potassium were checked periodically. The median follow-up was 16.5 months. No intra- or early post-operative complication occurred. All LESS adrenalectomies were completed successfully, except one with laparoscopic conversion. Hypokalemia was resolved in all cases and no patient required potassium supplements after surgery. Post-operative cure of hypertension was achieved in 63% of our patients. Overall, 84% of our PA patients had clinical improvement in blood pressure control after surgery. Our long-term experience revealed that LESS adrenalectomy is a safe and effective approach, which demonstrated comparable long-term cure and improvement of hypertension to a conventional laparoscopic series in treating PA.

Laparo-endoscopic Single-site (LESS) Adrenalectomy in Patients with Primary Hyperaldosteronism

Purpose: Laparoendoscopic single-site (LESS) adrenalectomy is a promising minimally invasive technique, however, the current evidence has not confirmed its long-term effectiveness in primary aldosteronism (PA). We conducted a study to analyze the long-term efficacy of LESS adrenalectomy in patients with PA. Material and Methods: A total of 49 patients who had been clinically confirmed with PA who had an indication for unilateral adrenalectomy were included in this study. Perioperative data were obtained for all patients. Blood pressure and the levels of serum aldosterone, renin, and potassium were checked periodically. The median follow-up was 16.5 months. Results: No intra- or early post-operative complication occurred. All LESS adrenalectomies were completed successfully, except one with laparoscopic conversion. Hypokalemia was resolved in all cases and no patient required potassium supplements after surgery. Post-operative cure of hypertension was achieved in 63% of our patients. Overall, 84% of our PA patients had clinical improvement in blood pressure control after surgery. Conclusions: Our long-term experience revealed that LESS adrenalectomy is a safe and effective approach, which demonstrated comparable long-term cure and improvement of hypertension to a conventional laparoscopic series in treating PA.

Needlescopic-assisted laparoendoscopic single-site adrenalectomy

Our objective was to compare the perioperative parameters of needle-assisted and conventional laparoendoscopic single-site adrenalectomy (LESS-A). We compared 23 patients undergoing needle-assisted LESS-A with 29 patients undergoing conventional LESS-A at Hiroshima University Hospital between November 2009 and February 2014. Needle-assisted LESS-A was performed using a MiniLap instrument (Stryker, San Jose, CA, USA). We used this instrument to protectively retract the liver at the right side of the tumor and the spleen at the left side by grasping with a Securea endoscopic surgical spacer (Hogy Medical Co., Ltd., Tokyo, Japan). Various parameters including insufflation time, estimated blood loss, pain scale, resumption of oral intake, transfusion rate, and complications were analyzed using the Mann-Whitney U test. In all cases, LESS-A was completed successfully with no major intraoperative complications. Patients in both treatment groups had similar age, body mass index, sex, and laterality. Significantly, needle-assisted LESS-A was performed using the transumbilical approach rather than the subcostal approach. The insufflation time of the needle-assisted LESS-A was shorter than that of the conventional LESS-A (p = 0.0335). No patients required intraoperative or postoperative blood transfusions. Retrospective design and the small sample size are main limitations of this study. Needle-assisted LESS-A was performed safely and in a manner that mitigated many of the difficulties of LESS surgery.

717 What changed after mastering surgical skills in laparoendoscopic single-site adrenalectomy?

717 What changed after mastering surgical skills in laparoendoscopic single-site adrenalectomy?

臍部単孔式腹腔鏡下副腎摘除術を施行した血液透析患者の1例

臍部単孔式腹腔鏡下副腎摘除術を施行した血液透析患者の1例

Laparoendoscopic single-site adrenalectomy sans transumbilical approach: initial experience in Japan.

The use of laparoendoscopic single-site (LESS) surgery has been increasing. The LESS procedure has been done for various urological diseases and studies have shown that it results in less pain, shorter hospi­tal stays and excellent cosmetic outcomes. We describe our initial experience with LESS adrenalectomy without the use of the transumbilical approach. The participants were 16 consecutive patients who underwent LESS adrenalectomy using a SILS port™ (Covidien, Mansfield, MA, USA) at Hiroshima University Hospital. Various parameters including the insufflation time, estimated blood loss, resumption of oral intake and complications were ana­lyzed. The adrenalectomy was completed successfully with no major intraoperative complications in 15 of the patients. One LESS adrenalectomy was converted to a conventional laparoscopic adrenalectomy by placement of two additional 12 mm trocars; this patient was therefore excluded from the study. The mean (range) patient age was 53.8 (35-69) years, body mass index (BMI) was 23.5 (20.7-27.2) kg/m2, tumor size was 19.8 (9-45) mm, insufflation time was 188.0 (95-340) min and estimated blood loss was 36.3 (10-80) mL. In all cases articulating instruments were used for satisfactory dissection and triangulation. One bowel injury (serosal) occurred and was repaired in the open laparotomy before SILS port™ insertion. All patients at the follow-up visit were satisfied and pleased with their scars. We found LESS adrenalectomy to be apparently safe, effective and minimally invasive for ad­renal diseases. In our opinion, LESS adrenalectomy without using the transumbilical approach is feasible and easy to introduce.