A new valve-less trocar for urologic laparoscopy: initial evaluation

Comparative assessment of safety and efficacy between the AirSeal system and conventional insufflation system in robot-assisted laparoscopic radical prostatectomy: a systematic review and meta-analysis

This meta-analysis aimed to compare perioperative outcome measures between the AirSeal system and conventional insufflation system in robot-assisted laparoscopic prostatectomy. Up to May 2024, comprehensive searches were conducted across various prominent databases worldwide, such as PubMed, Embase, and Google Scholar, focusing solely on English-language materials. Reviews and protocols devoid of published data were excluded, along with conference abstracts and articles unrelated to the study's aims. Primary outcome measures encompassed operative duration and hospitalization length, while secondary outcome measures included estimated blood loss and complications. The meta-analysis included five cohort studies, encompassing a total of 1503 patients. In comparison to the conventional insufflation system group, the AirSeal group displayed shorter operative times (WMD - 15.62, 95% CI - 21.87 to - 9.37; p < 0.00001) and reduced hospital stays (WMD - 0.45, 95% CI - 0.60 to - 0.30; p < 0.00001). Fewer major complications (OR 0.15, 95% CI 0.03 to 0.66; p = 0.01). Notably, there were no significant differences observed in estimated blood loss or overall complications between the two groups. Compared to conventional insufflation systems, employing the AirSeal system in robot-assisted laparoscopic radical prostatectomy appears to potentially decrease operative time and hospital length of stay without a concurrent rise in estimated blood loss or complication rates.

Comparison of a Valveless Trocar System and Conventional Insufflation in Pediatric Urologic Surgery

Background: Conventional operative insufflation uses a one-way trocar to handle instruments while maintaining pneumoperitoneum. In 2007, the AirSeal® valveless trocar insufflation system was introduced, which maintains stable pneumoperitoneum while continuously evacuating smoke. Although this device has been validated in adult patients, it has not been extensively validated in the pediatric population. Materials and Methods: A retrospective cohort study of pediatric urology patients aged 0 to 21 who underwent laparoscopic pyeloplasty between March 2016 and October 2021 was performed. Intraoperative physiologic parameters, procedure characteristics, postoperative outcomes, and demographics of each patient in whom either AirSeal insufflation system (AIS) or conventional insufflation system (CIS) was utilized were obtained from hospital records. Data were compared across the AIS and CIS cohorts. The primary outcomes were intraoperative anesthetic and physiologic parameters, including end tidal carbon dioxide, oxygen saturation, body temperature, positive inspiratory pressure, systolic blood pressure, and heart rate. Results: There were no significant differences in the anesthetic and physiologic parameters in the AIS and CIS groups. In addition, no differences in demographics, procedural characteristics, or complication rates were found between the cohorts. Conclusion: The AirSeal valveless trocar insufflation system demonstrates comparable intraoperative anesthetic and physiologic outcomes compared to conventional one-way valve insufflation in pediatric laparoscopic pyeloplasty. Certain surgeon-related qualitative metrics are underappreciated in this study, however, including improved visualization with vigorous suctioning and pressure maintenance with frequent instrument exchanges. Surgeon experience may mask the benefits of these characteristics as it pertains to quantitative surgical outcomes such as estimated blood loss, operative time, and perioperative complications.

Escape of surgical smoke particles, comparing conventional and valveless trocar systems

BACKGROUND

During minimal access surgery, surgical smoke is produced which can potentially be inhaled by the surgical team, leading to several health risks. This smoke can escape from the abdominal cavity into the operating room due to trocar leakage. The trocars and insufflator that are used during surgery influence gas leakage. Therefore, this study compares particle escape from a valveless (Conmed AirSeal iFS), and a conventional (Karl Storz Endoflator) system.

MATERIALS AND METHODS

Using an in vitro model, a conventional and a valveless trocar system were compared. A protocol that simulated various surgical phases was defined to assess the surgical conditions and particle leakage. Insufflation pressures and instrument diameters were varied as these are known to affect gas leakage.

RESULTS

The conventional trocar leaked during two distinct phases. Removal of the obturator caused a sudden release of particles. During instrument insertion, an average of 211 (IQR 111) particles per second escaped when using the 5 mm diameter instrument. With the 10 mm instrument, 50 (IQR 13) particles per second were measured. With the conventional trocar, a higher abdominal pressure increased particle leakage. The valveless trocar demonstrated a continuously high particle release during all phases. After the obturator was removed, particle escape increased sharply. Particle escape decreased to 1276 (IQR 580) particles per second for the 5 mm instrument insertion, and 1084 (IQR 630) particles per second for 10 mm instrument insertion. With the valveless trocar system, a higher insufflation pressure lowered particle escape.

CONCLUSIONS

This study shows that a valveless trocar system releases more particles into the operating room environment than a conventional trocar. During instrument insertion, the leakage through the valveless system is 6 to 20 times higher than the conventional system. With a valveless trocar, leakage decreases with increasing pressure. With both trocar types leakage depends on instrument diameter.

Comparison of laparoscopic partial nephrectomy performed with AirSeal® system vs. standard insufflator: results from a referral center

Objective

To compare perioperative and oncologic surgical outcomes during laparoscopic partial nephrectomy (LPN) performed by standard carbon dioxide insufflation, with those from surgeries in which the AirSeal® intelligent insufflation system was used for renal tumors.

Materials and methods

A total of 27 patients with renal tumor were identified, 14 underwent LPN with AirSeal® (group A) and 13 LPN with standard insufflator (group B), respectively. Demographic baseline characteristics were similar in the two groups.

Results

The size of the tumor was largest in group B (29.64 vs. 32.1 mm). The mean operative time was shorter in the AirSeal® group [group A: mean 109.0 min, median 107.5 min, interquartile range (IQR) 85; group B: mean 121.0 min, median 120.0 min, IQR 50.0]. Positive margin rates were absent in the two groups. Estimated blood loss presented a difference in the perioperative period (group A: mean 1.5 g/dL, median 1.45 g/dL; group B: mean 2.15 g/dL, median 2.2 g/dL). Time to ischemia was found to be shorter in group A with a median of 18 min compared to a median of 20 min in group B. No subcutaneous emphysema, pneumothorax, and pneumomediastinum cases occurred in either group. A postoperative complication developed in one patient requiring superselective embolization.

Conclusion

In selected patients, our preliminary surgical experience has shown that the LPN procedure performed with the aid of the AirSeal® intelligent insufflation system can be used to treat even medium-/high-complexity kidney lesions, with a reduction in operating times, lower rates of complications, and perioperative blood loss.

Clinical trial registration

AirSealV1.

The Usefulness of AirSeal™ Intelligent Flow System in Gas Insufflation Total Endoscopic Thyroidectomy

Total endoscopic thyroidectomy (TET) using low CO2 insufflation provides cosmetic advantage, excellent working space and visibility. On the contrary, suctioning blood or mist/smoke produced by energy device application causes narrowing of working space especially in neck surgery. In this regard, AirSeal intelligent flow system would be particularly suitable in TET. However, the benefit of AirSeal is unknown in TET unlike abdominal surgery. Therefore, the impact of AirSeal was evaluated in TET in this study. Twenty patients who underwent total endoscopic hemithyroidectomy were retrospectively analyzed. Insufflation was conducted by either conventional or AirSeal system according to the surgeon's preference. Short-term surgical outcomes including operation time, bleeding, frequency of scope cleaning, and disappearance of subcutaneous emphysema were compared as well as actual visibility. AirSeal application dramatically reduced obstacle smoke/mist and prevented narrowing working space by suctioning. Frequency of scope cleaning was significantly less in AirSeal group than that in conventional group (p = 0.016). In patients with nodule < 5 cm, intraoperative hemorrhage was less in AirSeal group than that in the counterpart (p = 0.077) regardless of larger nodule size in AirSeal group (p = 0.058). Notably, subcutaneous emphysema around surgical cavity disappeared significantly earlier in AirSeal group than in the counter parts (p = 0.019). On the contrary, AirSeal application did not shorten operation time in the current study. AirSeal provided excellent visibility and seamless operation. AirSeal has great potential to decrease not only surgeon's stress but surgical invasion on patients. The results in this study give rational to AirSeal application to TET.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03257-0.

The Role of AirSeal in Robotic Urologic Surgery: A Systematic Review

Introduction: The adoption of a valveless trocar system in robotic surgery has allowed for stable pneumoperitoneum and constant smoke evacuation. The reported benefits of this system are improved visualization, lower abdominal pressures resulting in a decrease in cardiopulmonary complications, ileus, and postoperative pain. We endeavored to perform a systematic review of the available literature on the clinical and systems-based outcomes of AirSeal™ during robotic urologic surgery. Materials and Methods: We performed this review according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Our population of interest was any patient undergoing robotic urologic surgery. Our outcomes of interest were (1) clinical effectiveness, (2) safety parameters, and (3) health system outcomes. Results: Of 83 records identified and screened at title/abstract level, 17 were examined for full-text, of which 10 studies enrolling a total of 1765 patients (cohorts ranging in size from 11 to 642 patients) were ultimately used for review. AirSeal resulted in improved respiratory parameters, specifically lower inspiratory plateau pressure, lower minute volume, lower CO2 elimination rate, low end-tidal CO2, and higher static compliance. Two studies described decreased complication rates with low pneumoperitoneum. There were mixed results regarding AirSeal effect on operative time. Conclusion: Valveless trocar technology using the AirSeal system is a valuable adjunct to current robotic urologic surgery. The established benefits include improved cardiopulmonary parameters, particularly within the steep trendelenburg position that is common in pelvic surgery. Further studies are necessary to elucidate the effects on safety and hospital system-wide outcomes.

Valveless Trocar Versus Standard Pneumoperitoneum Insufflation System in Minimally Invasive Surgery: Impact on Postoperative Pain. A Systematic Review and Meta-Analysis

Background: The benefits of a valid pneumoperitoneum in laparoscopic surgery are counterbalanced by the possible negative effects of increased abdominal pressure and carbon dioxide (CO₂) insufflation, which are crucial factors in causing postoperative pain. The purpose of this work is to evaluate the effectiveness of the valveless trocar (VT) insufflation system in decreasing postoperative pain and influencing operative time, compared to a standard insufflation system. Methods: A systematic research was performed using MEDLINE, EMBASE, Central Cochrane Library, and CINAHL Plus for studies published up to June 2020. Randomized controlled trials (RCTs) on adult population evaluating the effects of VT versus a standard insufflation system in laparoscopic surgery and reporting postoperative pain level and operative time were included in the analysis. Data and study quality indicators were extracted independently by 2 authors using a standardized form. Statistical analysis was based on a random effect model, using the inverse variance method. Results: We identified 3 RCTs for a total of 245 patients. The meta-analysis showed a statistically significant reduction in shoulder pain with the use of VT at 24 hours: mean difference (MD) -7.9% (95% confidence interval [95% CI]: -1.29 to 0.29; z = 3.08; P = .002) and a nonstatistically significant increase in operation time: MD 5.80 (95% CI: -8.93 to 20.54; P = .44). Conclusion: Our study suggests a better shoulder pain control at 24 hours postoperation using new-generation VT for laparoscopic surgery compared to standard insufflation system. Weak evidence of increased operating time with the VT was observed considering only two of the three RCTs. PROSPERO registration number: CRD42020191835.

The impact of the AirSeal® valve-less trocar system in robotic colorectal surgery: a single-surgeon retrospective review

BACKGROUND

Traditional trocar systems suffer from several innate flaws due to their silicone seal design. The AirSeal^® is a valve-less trocar system that overcomes these flaws by utilizing a system of laminar flow and CO₂ recirculation. The purpose of this paper is to examine the effect of the AirSeal^® versus a traditional trocar system in operative time, EBL and post-operative complications. To the best of our knowledge, this is the first analysis of this system in robotic colorectal surgery.

METHODS

A single surgeon's database was reviewed and all LAR and right hemicolectomy robotic cases from 2014-2015 and 2017-2018 were included for analysis. Patient demographic information was evaluated and primary outcomes examined were operative time, EBL, post-operative complications and hospital LOS.

RESULTS

Ninety four patients were identified in the LAR cohort and 56 patients were identified in the right hemicolectomy cohort. Mean operative time for LAR was 293 ± 91.6 min in 2014-2015 and 232 ± 74.6 min in 2017-2018 (p = 0.001); however, this significant difference was not seen between right hemicolectomies. Mean EBL for LAR was 209 ± 189 cc in 2014-2015 and 150 ± 173.9 cc in 2017-2018 (p = 0.05); again, this significant difference was not appreciated for right hemicolectomies. There was no statistically significant difference in rates of wound infections, pneumonia, post-operative pneumonia, DVT/PE, intra-abdominal/pelvic abscesses, or unplanned 30-day readmission rate between 2014-2015 and 2017-2018. Length of stay was reduced in both populations between 2014-2015 and 2017-2018; however, it neither reached statistical significance.

CONCLUSION

In patients undergoing low anterior resections, the AirSeal^® trocar system demonstrated a statistically significant reduction in mean operative time and EBL compared to the traditional trocar system. There was also a trend towards decreased length of stay and post-operative complications with AirSeal^® use in low anterior resections and right hemicolectomies. In patients undergoing distal colorectal procedures, the AirSeal^® trocar system should be considered.

Improved Outcomes Utilizing a Valveless-Trocar System during Robot-assisted Radical Prostatectomy (RARP)

Introduction

To evaluate the effect of valveless trocar system (VTS) on intra-operative parameters, peri-operative outcomes, and 30-day postoperative complications in patients undergoing robotic-assisted laparoscopic prostatectomy.

Methods

A total of 200 consecutive patients undergoing Robot-assisted radical prostatectomy by a single surgeon were prospectively evaluated using either the valveless trocar (n = 100) or standard trocars (n = 100). Patient demographics, intra-operative parameters, length of stay, presence or absence of postoperative nausea and vomiting, analog pain score at 0-6 hours, 6-12 hours, 12-18 hours, and >24 hours, and 30-day postoperative complications were analyzed.

Results

There were no significant differences in estimated blood loss, intra-operative urine output, length of stay, or 30-day complication rates between the two groups. While the VTS group had higher Body Mass Index (BMI) (28.45 vs. 27.23; P = 0.049), the operative time was significantly shorter in the VTS group (146 minutes vs. 167 minutes; P < .005). The VTS group experienced fewer episodes of nausea (2% vs. 10%; P = 0.0172). The VTS group had less pain intensity compared to the control in the first 18 hours: 0-6 hours (1.9 vs. 2.5; P = 0.034), 6-12 hours (2.8 vs. 3.6; P = 0.044), and 12-18 hours (2.2 vs. 3.1; P = 0.049), respectively.

Conclusion

The use of a valveless trocar system during robot-assisted robotic prostatectomy may shorten operative times, and reduce postoperative pain scores and nausea episodes without increasing the 30-day complication rate. Further prospective randomized trials should be performed to validate these findings.

Low pressure gynecological laparoscopy (7mmHg) with AirSeal® System versus a standard insufflation (15mmHg): A pilot study in 60 patients

OBJECTIVES

To evaluate feasibility of performing benign gynecologic pathology low pressure (7mmHg) laparoscopy (LPL) with AirSeal^® system and to study benefits in terms of postoperative pain, when compared to a standard insufflation group (15mmHg).

MATERIALS AND METHODS

In this prospective randomized pilot study, 60 patients had laparoscopy for gynecologic benign pathology: 30 with 7mmHg and AirSeal system, and 30 with 15mmHg standard insufflator. The primary endpoint was incidence of shoulder pain. A postoperative questionnaire was completed by each patient to assess shoulder pain (Numeric Rating Scale [NRS], from 0 to 10) at H4, H8, H24, and consumption of morphinics was notified. During each procedure, anesthesia parameters were collected (peak airway pressure, systolic blood pressure, end tidal CO₂).

RESULTS

Laparoscopy was performed on 30 patients in AirSeal^®-LP group without need to increase pressure above 7mmHg, and no complication was reported. Incidence of shoulder pain was significantly lower in the AirSeal^®-LP group (23.3% vs. 73.3%, P<0.001). NRS shoulder pain was significantly lower in AirSeal^® LP group at hour 4, 8 and 24. Maximal values of ETCO₂, systolic blood pressure, and peak airway pressure were significantly lower in AirSeal^®-LP group.

CONCLUSION

LP (7mmHg) laparoscopy with AirSeal^® platform allows laparoscopic surgery with less postoperative shoulder pain. These results could facilitate the development of ambulatory laparoscopy.

Robotic partial nephrectomy performed with Airseal versus a standard CO2 pressure pneumoperitoneum insufflator: a prospective comparative study

BACKGROUND

Airseal represents a new generation of valveless and barrier-free surgical trocars that enable a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO₂) recirculation during surgery. The aim of the current study was to evaluate the potential advantages of the Airseal compared to a standard CO₂ insufflator in the field of robotic partial nephrectomy (RPN).

METHODS

Between October 2012 and April 2015, two cohorts of 122 consecutive patients with clinically localized renal cell carcinoma underwent RPN by a single surgeon, with the use of a standard CO₂ pressure insufflator (Group A, 55 patients) or Airseal (Group B, 67 patients) and were prospectively compared.

RESULTS

The two groups were similar in baseline, preoperative characteristics. The mean dimension of the lesion, as evaluated by contrast-enhanced CT scan, was 30 (median 28; IQR 2) and 39 mm (median 40; IQR 2) for Groups A and B, respectively (p < 0.05). The complexity of the treated tumors was similar, as indicated by the mean RENAL nephrometry score. Positive surgical margins rate was similar in both groups (3.6 vs 4.5 %, p = 0.8) as well as the need for postoperative blood transfusion (9.1 vs 4.5 %, p = 0.3) and the development of postoperative acute kidney injury (16.4 vs 10.4 %, p = 0.3). Mean operative time and warm ischemia time were significantly shorter in Group B. Moreover, a significant increase in the cases performed as "zero ischemia" was observed in Group B (7.3 vs 30 %, p < 0.01).

CONCLUSIONS

This is the first study comparing the Airseal with a standard CO₂ insufflator system in the field of the RPN. The preliminary outcomes in terms of overall operative time, warm ischemia time and cases performed as "zero ischemia" are better with respect to standard insufflators. The feasibility, safety and efficacy of combining laser tumor enucleation with the valve-free insufflation systems should be evaluated.

Comparison of Pneumoperitoneum Stability Between a Valveless Trocar System and Conventional Insufflation: A Prospective Randomized Trial

OBJECTIVE

To compare the variation in pneumoperitoneum and physiologic effects of patients undergoing laparoscopic renal surgery using the valveless trocar insufflation system (VI) vs a conventional insufflation system (CI).

METHODS AND MATERIALS

We conducted a single-center, randomized controlled trial in patients undergoing renal surgery at 15 mm Hg insufflation using a VI system vs a CI system. The primary outcome measured was variation in insufflation pressure, and end-tidal CO2 at 10 and 25 minutes.

RESULTS

Fifty-six patients (VI n = 28 or CI n = 28) met inclusion criteria and were randomized. There was significantly less variability in pressure readings, as measured by coefficient of variation, during VI compared to CI (7.8% vs 15.6%, P < .001). There was significantly less time spent within the range with pressure readings ≥18 mm Hg (median 0.2% vs 16.5%, P < .001) and ≤12 mm Hg (median 1.7% vs 5.6%, P = .011) during VI compared to CI. Additionally, there was significantly less time spent with pressure readings in the "unacceptable" range of ≥20 mm Hg (median 0% vs 0.08%, P < .001) and ≤10 mm Hg (median 0.09% vs 2.6%, P < .001) during the cases with VI compared to CI. End-tidal CO2 was significantly lower at 10 minutes (P = .036) after insufflation in the valveless trocar group compared to the conventional treatment group. There were no other significant differences in physiologic metrics.

CONCLUSION

Compared with a CI, the VI provides a significantly more stable pneumoperitoneum during laparoscopic renal surgery and lower end-tidal CO2 at 10 minutes.

Laparoscopic Toupet Fundoplication using an Air Seal Intelligent Flow System and Anchor Port in a 1.8-kg infant: A Technical Report

INTRODUCTION

We report a case of a 1.8-kg infant who had laparoscopic Toupet fundoplication (LTF) using the AirSeal Intelligent Flow System and Anchor Port (AP).

MATERIALS AND SURGICAL TECHNIQUE

Our case had severe gastroesophageal reflux in association with genetic and cardiac anomalies. Despite the patient being continuously fed, persistent vomiting caused failure to thrive, and LTF was performed at 4 months of age when he weighed 1.8 kg. The AirSeal Intelligent Flow System is a novel laparoscopic CO2 insufflation system that improves the visual field by constantly evacuating smoke and providing a more stable pneumoperitoneum. The AP is a recently developed, stretchable, elastomeric, low-profile cannula. Three 5-mm AP were inserted: one subumbilically for the scope and one in both the right and left upper abdomen for the surgeon. A 5-mm AirSeal trocar was inserted in the left lower abdomen for the assistant. The gastrosplenic ligament was dissected free, and the intra-abdominal esophagus was prepared. A posterior hiatoplasty was performed, followed by the 270° fundoplication. During the fundoplication, the esophagus was fixed to the crus and then the right and left wraps were fixed to the esophagus. Pneumoperitoneum was maintained stably throughout the LTF procedure, with optimal operative field. Total operating time for LTF was 90 min. Body temperature dropped from 37.4°C to 35.7°C during pneumoperitoneum but resolved once pneumoperitoneum was ceased. Postoperative progress was uneventful, and an upper gastrointestinal study on postoperative day 2 showed no residual gastroesophageal reflux.

DISCUSSION

We believe the AirSeal Intelligent Flow System and AP contributed to the successful completion of LTF in a 1.8-kg infant.

Utilization of a novel valveless trocar system during robotic-assisted laparoscopic prostatectomy

PURPOSE

To evaluate the effect of a novel valveless trocar system (VTS) on perioperative outcomes in patients undergoing robotic-assisted laparoscopic prostatectomy (RALP).

METHODS

A single-institution retrospective review was performed of 792 patients undergoing RALP. Preoperative patient variables, tumor characteristics, and perioperative variables were collected and analyzed. The first 150 patients were excluded from analysis to account for the learning curve of robotic surgery. Univariate and multivariate linear regression models were used to assess factors affecting operative time (ORT).

RESULTS

A total of 257 and 385 patients underwent RALP utilizing the VTS and conventional insufflation, respectively. There were no significant differences in American Society of Anesthesiologist score, body mass index (BMI), prostate volume, final Gleason score, estimated blood loss, and complications between the cohorts. The only difference noted was a significantly shorter mean ORT in the VTS cohort (149.5 vs. 170.1 min, p < 0.0001). In light of this finding, further analysis was performed to identify associations with ORT. Multivariable analysis demonstrated that VTS, BMI, final Gleason score, prostate volume, surgeon, and node dissection were significantly associated with ORT. The use of the VTS decreased mean ORT by 23.2 min when controlling for confounding factors (p < 0.001). The performance of a nerve sparing operation was found to decrease ORT by 15.9 min (p < 0.001), though more often performed for lower-risk disease.

CONCLUSION

The use of a novel VTS demonstrated decreased ORT in patients undergoing RALP when controlling for confounding factors. Prospective randomized trials are needed to evaluate its ultimate benefit in various surgical cohorts.

Subcutaneous emphysema--beyond the pneumoperitoneum

New additional risks factors that may act to increase the risk of subcutaneous emphysema include total gas volume, gas flow rate, valveless trocar systems, and robotic fulcrum forces.

Background:

Subcutaneous emphysema and gas extravasation outside of the peritoneal cavity during laparoscopy has consequences. Knowledge of the circumstances that increase the potential for subcutaneous emphysema is necessary for safe laparoscopy.

Methods:

A literature review and a PubMed search are the basis for this review.

Conclusions:

The known risk factors leading to subcutaneous emphysema during laparoscopy are multiple attempts at abdominal entry, improper cannula placement, loose fitting cannula/skin and fascial entry points, use of >5 cannulas, use of cannulas as fulcrums, torque of the laparoscope, increased intra-abdominal pressure, procedures lasting >3.5 hours, and attention to details. New additional risk factors acting as direct factors leading to subcutaneous emphysema risk and occurrence are total gas volume, gas flow rate, valveless trocar systems, and robotic fulcrum forces. Recognizing this spectrum of factors that leads to subcutaneous emphysema will yield greater patient safety during laparoscopic procedures.

Comparison of a standard CO₂ pressure pneumoperitoneum insufflator versus AirSeal: study protocol of a randomized controlled trial

Background

AirSeal™ is a novel class of valve-free insufflation system that enables a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO₂) recirculation during laparoscopic surgery. Comparison data to standard CO₂ pressure pneumoperitoneum insufflators is scarce. The aim of this study is to evaluate the potential advantages of AirSeal™ compared to a standard CO₂ insufflator.

Methods/Design

This is a single center randomized controlled trial comparing elective laparoscopic cholecystectomy, colorectal surgery and hernia repair with AirSeal™ (group A) versus a standard CO₂ pressure insufflator (group S). Patients are randomized using a web-based central randomization and registration system. Primary outcome measures will be operative time and level of postoperative shoulder pain by using the visual analog score (VAS). Secondary outcomes include the evaluation of immunological values through blood tests, anesthesiological parameters, surgical side effects and length of hospital stay. Taking into account an expected dropout rate of 5%, the total number of patients is 182 (n = 91 per group). All tests will be two-sided with a confidence level of 95% (P <0.05).

Discussion

The duration of an operation is an important factor in reducing the patient’s exposure to CO₂ pneumoperitoneum and its adverse consequences. This trial will help to evaluate if the announced advantages of AirSeal™, such as clear sight of the operative site and an exceptionally stable working environment, will facilitate the course of selected procedures and influence operation time and patients clinical outcome.

Trial registration

ClinicalTrials.gov NCT01740011, registered 23 November 2012.

Massive subcutaneous emphysema in robotic sacrocolpopexy

Robotic sacrocolpopexy may increase insufflation complications including massive subcutaneous emphysema.

The advent of robotic surgery has increased the popularity of laparoscopic sacrocolpopexy. Carbon dioxide insufflation, an essential component of laparoscopy, may rarely cause massive subcutaneous emphysema, which may be coincident with life-threatening situations such as hypercarbia, pneumothorax, and pneumomediastinum. Although the literature contains several reports of massive subcutaneous emphysema after a variety of laparoscopic procedures, we were not able to identify any report of this complication associated with laparoscopic or robotic sacrocolpopexy. Massive subcutaneous emphysema occurred in 3 women after robotic sacrocolpopexy in our practice. The patients had remarkable but reversible physical deformities lasting up to 1 week. A valveless endoscopic dynamic pressure system was used in all 3 of our cases. Our objective is to define the risk of massive subcutaneous emphysema during robotic sacrocolpopexy in light of these cases and discuss probable predisposing factors including the use of valveless endoscopic dynamic pressure trocars.

Laparoscopic surgery for advanced gastric cancer: current status and future perspectives

Laparoscopic gastrectomy has been widely accepted especially in patients with early-stage gastric cancer. However, the safety and oncologic validity of laparoscopic gastrectomy for advanced gastric cancer are still being debated. Since the late 90s', we have been engaged in developing a stable and robust methodology of laparoscopic radical gastrectomy for advanced gastric cancer, and have established laparoscopic distinctive technique for suprapancreatic lymph node dissection, namely the outermost layer-oriented medial approach. In this article, We present the development history of this method, and current status and future perspectives of laparoscopic gastrectomy for advanced gastric cancer based on our experience and a review of the literature.

Prospective comparison between the AirSeal® System valve-less Trocar and a standard Versaport™ Plus V2 Trocar in robotic-assisted radical prostatectomy

BACKGROUND AND PURPOSE

To prospectively compare the AirSeal® System valve-less Trocar with a standard Versaport™ Plus V2 Trocar as assistant insufflating port in transperitoneal and extraperitoneal robotic-assisted radical prostatectomy (t-RARP/e-RARP).

PATIENTS AND METHODS

Two consecutive cohorts of patients undergoing RARP using either a 12 mm AirSeal valve-less Trocar (n=19 [14 t-RARP/5 e-RARP]) or a 12 mm Versaport Plus V2 Trocar (n=17 [11 t-RARP/6 e-RARP]) were prospectively evaluated. Age, body mass index, tumor characteristics, and surgical approach were similar in both cohorts. Besides relevant clinical data, episodes of pressure loss (<8 mm Hg), the number of necessary trocar manipulations, the frequency of camera cleaning, and overall carbon dioxide (CO2) consumption were recorded and compared.

RESULTS

Mean surgical time was 175 minutes in the AirSeal and 166 minutes in the Versaport group (p=0.55). Whereas in the AirSeal group, only one episode of pressure loss <8 mm Hg was observed; this occurred in mean 38 times in the Versaport group (p<0.0001). No trocar manipulations for specimen or needle retrieval were necessary in the AirSeal group in contrast to in mean 15 in the Versaport group (p<0.0001). Otherwise, no appreciable differences regarding overall operating time, blood loss, camera cleaning, or overall CO2 consumption were observed for the present study. Patient CO2 absorption was not evaluated.

CONCLUSIONS

In the present study, the AirSeal Trocar offered a more stable pneumocavity and facilitated specimen retrieval and needle extraction.

Benchtop evaluation of pressure barrier insufflator and standard insufflator systems

BACKGROUND

Previous experimental research has reported minimal differences in pressure maintenance between different versions of standard insufflators (SI). However, a recent report identified potential clinical benefits with a valveless pressure barrier insufflator (PBI). We sought to perform a benchtop objective evaluation of SI and PBI systems.

METHODS

A rigid box system with continuous pressure manometry was used to evaluate a PBI (Surgiquest Airseal) and two SIs (SI1 = Stryker PneumoSure High Flow Insufflator and SI2 = Storz SCB Thermoflator). Pressure maintenance of 15 mmHg was evaluated during experimental conditions of leakage from a 5 mm port site, leakage from a 12 mm port site, and continuous suction.

RESULTS

With leakage from the 5 mm port site, the PBI maintained pressure of >13 mmHg whereas the pressures dropped moderately with the SI1 (7-13 mmHg) and SI2 insufflators (3-7 mmHg) and did not regain goal pressure until leakage was stopped. With leakage from 12 mm port site, the PBI pressure decreased to 9-11 mmHg, whereas the SI1 and SI2 lost insufflation pressures completely. The PBI maintained pressure of >11 mmHg during continuous suction while the SI1 and SI2 lost pressure entirely, and actually showed negative pressure from air suction into the rigid box system. When evaluated statistically with the mixed model repeated measures ANOVA, the SI1 and SI2 performed similarly while the PBI maintained increased pressure.

CONCLUSIONS

In the experimental rigid box system, the PBI more successfully maintained pressure in response to leakage and suction than SIs.

Current status of laparoendoscopic single-site surgery in urologic surgery

Since the introduction of laparoscopic surgery, the promise of lower postoperative morbidity and improved cosmesis has been achieved. Laparoendoscopic single-site surgery (LESS) potentially takes this further. Following the first human urological LESS report in 2007, numerous case series have emerged, as well as comparative studies comparing LESS with standard laparoscopy. However, comparative series between conventional laparoscopy and LESS for different procedures suggest a non-inferiority of LESS over standard laparoscopy, but the only objective benefit remains an improved cosmetic outcome. Challenging ergonomics, instrument clashing, lack of true triangulation, and in-line vision are the main concerns with LESS surgery. Various new instruments have been designed, but only experienced laparoscopists and well-selected patients are pivotal for a successful LESS procedure. Robotic-assisted LESS procedures have been performed. The available robotic platform remains bulky, but development of instrumentation and application of robotic technology are expected to define the actual role of these techniques in minimally invasive urologic surgery.

Laparoendoscopic single-site porcine nephrectomy using a novel valveless trocar system

BACKGROUND AND PURPOSE

The AirSeal™ access system is a novel laparoscopic trocar that uses airflow to create insufflation pressure without the need for a physical seal or valve. By eliminating all valve elements within the lumen of the canula, the port provides a platform that accommodates multiple instruments of any diameter, shape, or combination and is ideally suited for laparoendoscopic single-site surgery (LESS). We present our initial experience with valveless trocars in traditional urologic laparoscopic cases and a porcine LESS nephrectomy series.

MATERIALS AND METHODS

Nine transperitoneal LESS nephrectomies were performed in a live porcine model using the 27-mm oval valveless trocar. All working instruments were placed through the single port, and the specimen was extracted through the 4-cm port site.

RESULTS

All cases were completed without technical or operative complications. The porcine single-port nephrectomy (n=9) was successfully performed in a mean operative time of 24 minutes through the single 27-mm oval trocar. This accommodated a 5-mm laparoscope, multiple 5-mm instruments, the Endo GIA stapler, and the 15-mm Endocatch bag without loss of insufflation pressure. Condensation and smudging of the laparoscope were minimized, improving visualization and efficiency. The system allowed for use of suction without significant loss of insufflation pressure.

CONCLUSION

The initial experience with the AirSeal valveless trocar system in LESS is encouraging. This technology may offer significant benefits over traditional laparoscopic trocars and single -port platforms and appears particularly suited to facilitate LESS.

Use of the valveless trocar system reduces carbon dioxide absorption during laparoscopy when compared with standard trocars

OBJECTIVES

To prospectively compare a novel type of valveless trocar that creates a curtain of pressurized carbon dioxide [CO(2)] gas (which maintains pneumoperitoneum at a lower gas flow rate) with standard trocars; to quantify the volume of CO(2) used; and to characterize CO(2) elimination during laparoscopic renal surgery.

METHODS

A total of 51 patients undergoing laparoscopic renal surgery by a single surgeon were prospectively evaluated using either the valveless trocar (n = 26) or standard trocars (n = 25). Patient demographics, operative time, volume of CO(2) gas consumed, CO(2) elimination, perioperative parameters, and postoperative complications were recorded and analyzed.

RESULTS

Both patient cohorts were comparable in their preoperative demographics, including body mass index, the number of patients with chronic obstructive pulmonary disease, and smoking history. Mean operative time was lower in the valveless trocar cohort (124.1 minutes) compared with the conventional trocar group (145.6 minutes), P = .047. Use of the valveless trocar was associated with a lower volume of intraoperative CO(2) consumed (120.0 ± 82.8 vs 300.6 ± 191.5; P < .001) and reduced CO(2) elimination compared with standard trocar use after the first 16 minutes of insufflation (P < .05). Minimal complications occurred, including 2 cases of subcutaneous emphysema in the valveless trocar group, and 1 case of respiratory acidosis in the conventional trocar group.

CONCLUSIONS

Use of a valveless trocar significantly reduced CO(2) consumption during transperitoneal laparoscopy. The valveless trocar also demonstrated significantly reduced CO(2) elimination and absorption when compared with the standard trocar.

Laparoendoscopic single-site and natural orifice transluminal endoscopic surgery in urology: a critical analysis of the literature

CONTEXT

Natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single-site surgery (LESS) have been developed to benefit patients by enabling surgeons to perform scarless surgery.

OBJECTIVE

To summarize and critically analyze the available evidence on the current status and future perspectives of LESS and NOTES in urology.

EVIDENCE ACQUISITION

A comprehensive electronic literature search was conducted in June 2010 using the Medline database to identify all publications relating to NOTES and LESS in urology.

EVIDENCE SYNTHESIS

In urology, NOTES has been completed experimentally via transgastric, transvaginal, transcolonic, and transvesical routes. Initial clinical experience has shown that NOTES urologic surgery using currently available instruments is indeed possible. Nevertheless, because of the immaturity of the instrumentation, early cases have demanded high technical virtuosity. LESS can safely and effectively be performed in a variety of urologic settings. As clinical experience increases, expanding indications are expected to be documented and the efficacy of the procedure to improve. So far, the quality of evidence of all available studies remains low, mostly being small case series or case-control studies from selected centers. Thus, the only objective benefit of LESS remains the improved cosmetic outcome. Prospective, randomized studies are largely awaited to determine which LESS procedures will be established and which are unlikely to stand the test of time. Technology advances hold promise to minimize the challenging technical nature of scarless surgery. In this respect, robotics is likely to drive a major paradigm shift in the development of LESS and NOTES.

CONCLUSIONS

NOTES is still an investigational approach in urology. LESS has proven to be immediately applicable in the clinical field, being safe and feasible in the hands of experienced laparoscopic surgeons. Development of instrumentation and application of robotic technology are expected to define the actual role of these techniques in minimally invasive urologic surgery.