Benchtop evaluation of pressure barrier insufflator and standard insufflator systems

Valveless and conventional insufflation on pneumoperitoneum-related complications in robotic partial nephrectomy: a systematic review and meta-analysis of prospective studies

INTRODUCTION

The use of pneumoperitoneum is an essential step for performing laparoscopic and robotic surgery. Pneumoperitoneum insufflation can cause complications such as pneumothorax, subcutaneous emphysema, and pneumomediastinum. The purpose of this meta-analysis is to compare the safety of using the conventional insufflation system versus a Valveless insufflation system as devices for manufacturing pneumoperitoneum in robotic-assisted nephrectomy.

METHODS

A comprehensive literature search was conducted on PUBMED, EMBASE, SCOPUS, and Cochrane, from inception until January 2024. Randomized and nonrandomized prospective studies were included in the meta-analysis, performed by the R+ Rstudio.

RESULTS

Three publications encompassing 478 patients were included. We observed no difference in SCE (OR 0.60, CI 95% 0.27;1.34, p = 0.134, I2 = 0), PNM (OR 0.82, CI 95% 0.24;2.78, p = 0.558, I2 = 0), When comparing groups conventional insufflation system (CIS) versus AirSealTM insufflation system (AIS) with pneumoperitoneum pressure of 15 mmHg or 12 mmHg.

CONCLUSION

The presented data showed no difference between the AIS when compared with CIS in Pneumoperitoneum insufflation-related complications.

Use of mixed gas pneumoperitoneum during minimally invasive surgery: a systematic review of human and mouse modelled laparoscopic interventions

The formation of pneumoperitoneum involves the process of inflating the peritoneal cavity during laparoscopic and typically uses CO2 as the insufflation gas. This review aims to identify ideal gas mixtures for establishing the pneumoperitoneum with animal and human studies undertaken up to the writing of this review. A systematic search of PubMed, OVID, and clinicaltrials.gov was performed to identify studies on the utilisation of mixed gases in laparoscopic surgery, including non-randomised/randomised trials, animal and human studies, and studies with inflating pressures between 12 and 16 mmHg. ROBINS-I and RoB2 tool was used to assess the risk of bias. A narrative synthesis of results was performed due to the heterogeneity of the studies. 5 studies from the database search and 5 studies from citation search comprising 128 animal subjects and 61 human patients were found. These studies collated results based on adhesion formation (6 studies), pain scores (2 studies) and other outcomes, with results favouring the use of carbon dioxide + 10% nitrous oxide + 4% oxygen. This has shown a significant reduction in adhesion formation, pain scores and inflammation. The use of this gas mixture provides promising results for future practice. Several of the studies available require larger sample sizes to develop a more definitive answer on the effects of different gas mixtures. Furthermore, the number of confounding factors in randomised trials should be reduced so that each component of the current suggested gas mixture can be tested for safety and efficacy.

Comparison of AirSeal versus conventional insufflation system for retroperitoneal robot-assisted laparoscopic partial nephrectomy: a randomized controlled trial

PURPOSE

AirSeal is a valve-less trocar insufflation system which is widely used in robotic urologic surgeries. More evidence is needed concerning the application and cost of AirSeal in retroperitoneal robot-assisted laparoscopic partial nephrectomy.

METHODS

We conducted a randomized controlled trial enrolling 62 patients who underwent retroperitoneal robot-assisted laparoscopic partial nephrectomy from February 2022 to February 2023 in the Peking Union Medical College Hospital. Patients were randomly assigned into AirSeal insufflation (AIS) group and conventional insufflation (CIS) group. The primary outcome was the rate of subcutaneous emphysema (SCE).

RESULTS

The SCE rate in the AIS group (12.9%) was significantly lower than that in the CIS group (35.5%) (P = 0.038). Lower maximum end-tidal carbon dioxide (CO2) (41 vs 45 mmHg, P = 0.011), PaCO2 at the end of the operation (40 vs 45 mmHg, P < 0.001), maximum tidal volume (512 vs 570 ml, P = 0.003), frequency of lens cleaning (3 vs 5, P < 0.001), pain score at 8 h (3 vs 4, P = 0.025), 12 h (2 vs 3, P = 0.029) postoperatively and at time of discharge (1 vs 2, P = 0.002) were observed in the AIS group, despite a higher hospitalization cost (68,197 vs 64658RMB, P < 0.001). Logistic regression analysis identified insufflation approach was the only influencing factor for the occurrence of SCE events.

CONCLUSION

AirSeal insufflation system exhibited similar efficacy and improved safety for retroperitoneal robot-assisted laparoscopic partial nephrectomy than conventional insufflation system, despite an affordable increase of hospitalization costs.

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.

The impact of AirSeal® on complications and pain management during robotic-assisted radical prostatectomy: a single-tertiary center study

PURPOSE

We aimed to compare perioperative outcomes, post-operative complications, and opioid use between AirSeal® and non-AirSeal® robotic-assisted radical prostatectomy (RARP).

METHODS

We retrospectively collected data on 326 patients who underwent elective RARP at our institution either with or without AirSeal®. The first 60 cases were excluded accounting for the institutions' learning curve of RARP. Patient demographics, oncologic, pathologic, and surgical characteristics between AirSeal® and non-AirSeal® cases were compared. Furthermore, outcomes of interest including operative time, length of stay, morbidity, and opioid use for pain management were compared between the two groups. Univariate linear and logistic regression models were developed.

RESULTS

The AirSeal® group consisted of 125 (38.3%) patients while the non-AirSeal® group consisted of 201 (61.7%) patients. No statistically significant difference was seen in terms of patient demographics, oncologic characteristics, surgical characteristics, and pathologic characteristics between the two groups. In addition, univariate linear regression showed that RARP with AirSeal® displayed shorter operative times by 12.3 min and a shorter length of hospital stay by 0.5 days compared to the non-AirSeal® group (p < 0.001). Furthermore, the AirSeal® group witnessed lower odds of Clavien-Dindo (CVD) Class > 2 complications (OR = 0.102) and a lower need for opioid use (OR = 0.49) compared to the non-AirSeal® group (p < 0.022).

CONCLUSION

RARP using AirSeal® is associated with shorter operative times, shorter length of hospital stays, lower odds of CVD > 2 complications, and lower odds of opioid use with respect to non-AirSeal® RARP. The efficacy and cost effectiveness of using the AirSeal® system during RARP should be further studied and evaluated by clinical trials.

Clinical trial protocol for P-NeLoP: a randomized controlled trial comparing the feasibility and outcomes of robot-assisted partial nephrectomy with low insufflation pressure using AirSeal versus standard insufflation pressure (UroCCR no. 85 study)

Robot-assisted partial nephrectomy (RAPN) is the standard of care for small, localized kidney tumors. This surgery is conducted within a short hospital stay and can even be performed as outpatient surgery in selected patients. In order to allow early rehabilitation of patients, an optimal control of postoperative pain is necessary. High-pressure pneumoperitoneum during surgery seems to be the source of significant pain during the first hours postoperatively. Our study is a prospective, randomized, multicenter, controlled study which aims to compare post-operative pain at 24 h between patients undergoing RAPN at low insufflation pressure (7 mmHg) and those operated on at standard pressure (12 mmHg) using the AirSeal system.This trial is registered in the US National Library of Medicine Trial Registry (NCT number: NCT05404685).

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.

Components of a safe cystectomy service during coronavirus disease 2019 in a high-volume centre

Objective:

Delivery of a safe cystectomy service is a multidisciplinary exercise. In this article, we detail the measures implemented at our institution to deliver a cystectomy service for bladder cancer patients during coronavirus disease 2019 (COVID-19).

Methods:

A ‘one-stop’ enhanced recovery clinic had been established at our hospital, consisting of an anaesthetist, an exercise testing service, urinary diversion nurses, clinical nurse specialists and surgeons. During COVID-19, we modified these processes in order to continue to provide urgent cystectomy safely for bladder cancer. We collected patients’ outcomes prospectively measuring demographic characteristics, oncological and perioperative outcomes, the presence of COVID-19 symptoms and confirmed COVID-19 test results.

Results:

From March to May 2020, 25 patients underwent radical cystectomy for bladder cancer. Twenty-four procedures were performed with robotic assistance and one open as part of a research trial. We instituted modifications at various multidisciplinary steps, including patient selection, preoperative optimisation, enhanced recovery protocols, patient counselling and perioperative protocols. Thirty-day mortality was 0%. The 30-day rate of Clavien ⩾3 complications was 8%. Postoperatively, none of the patients developed COVID-19 based on World Health Organization criteria and testing.

Conclusion:

We safely delivered a complex cystectomy service during the peak of the COVID-19 pandemic without any COVID-19-related morbidity or mortality.

Level of evidence:

Level 2b.

Intraoperative Measures to Reduce the Risk of COVID-19 Transmission During Minimally Invasive Procedures: A Systematic Review and Critical Appraisal of Societies' Recommendations

BACKGROUND

The coronavirus 2019 pandemic and the hypothetical risk of virus transmission through aerosolized CO2 or surgical smoke produced during minimally invasive surgery (MIS) procedures have prompted societies to issue recommendations on measures to reduce this risk. The aim of this systematic review is to identify, summarize and critically appraise recommendations from surgical societies on intraoperative measures to reduce the risk of severe acute respiratory syndrome coronavirus 2 transmission to the operative room (OR) staff during MIS.

METHODS

Medline, Embase, and Google Scholar databases were searched using a search strategy or free terms. The search was supplemented with searches of additional relevant records on coronavirus 2019 resource websites from Surgical Associations and Societies. Recommendations published by surgical societies that reported on the intraoperative methods to reduce the risk of severe acute respiratory syndrome coronavirus 2 transmission to the OR staff during MIS were also reviewed for inclusion. Expert opinion articles were excluded. A preliminary synthesis was performed of the extracted data to categorize and itemize the different types of recommendations. The results were then summarized in a narrative synthesis.

RESULTS

Thirty-three recommendation were included in the study. Most recommendations were targeted to general surgery (13) and gynecology (8). Areas covered by the documents were recommendations on performance of laparoscopic/robotic surgery versus open approach (28 documents), selection of surgical staff (13), management of pneumoperitoneum (33), use of energy devices (20), and management of surgical smoke and pneumoperitoneum desufflation (33) with varying degree of consensus on the specific recommendations among the documents.

CONCLUSIONS

While some of the early recommendations advised against the use of MIS, they were not strictly based on the available scientific evidence. After further consideration of the literature and of the well-known benefits of laparoscopy to the patient, later recommendations shifted to encouraging the use of MIS as long as adequate precautions could be taken to protect the safety of the OR staff. The release and implementation of recommendations should be based on evidence-based practices that allows health care systems to provide safe surgical and medical assistance.

Technical Performance of Continuous Pressure Insufflators Versus Traditional Insufflators in the Presence of Leaks During Laparoscopic Surgery

Background. New insufflators have been developed to manage leaks emanating from the working cavity during laparoscopic surgery. Little data have been published to show the performance of these insufflators. This study evaluates the performance of 2 modern continuous pressure insufflators in various leak conditions. Methods. Performance of a new continuous pressure insufflator, EVA15 (Palliare, Galway, Ireland), was compared with that of a continuous pressure insufflator, Airseal intelligent Flow System (iFS) (CONMED, Utica, NY), and a traditional intermittent pressure insufflator, Endoflator 40 (KARL STORZ, Tuttlingen, Germany). Six different leak scenarios were created in a swine model to create different dynamic leak profiles of between 5 and 15 L/min. Pressure deviation from setting was measured for each insufflator tested. The following were calculated: (a) mean absolute difference of measured insufflation pressure vs. the insufflator pressure setting for the 50 second measurement period (MAD) and (b) standard deviation of the absolute differences (SD). Results. The average mean absolute pressure difference between the EVA15 and Airseal is .27 mmHg. However, the average mean absolute pressure difference between the EVA15 and Endoflator 40 is 2.62 mmHg. Conclusions. Continuous pressure insufflators provide superior pressure delivery performance in leak situations when compared against a traditional intermittent pressure insufflator. No clinically significant performance difference was observed when comparing the EVA15 and Airseal iFS insufflators in the tested leak situations.

Comparison of the Safety and Efficacy of Valveless and Standard Insufflation During Robotic Partial Nephrectomy: A Prospective, Randomized, Multi-institutional Trial

OBJECTIVE

To use a randomized, prospective, multi-institutional study to compare the safety and efficacy of conventional insufflation (CIS) and valveless insufflation (AirSeal Insufflation - AIS) at the conventional pressure of 15 mm Hg in robot-assisted partial nephrectomy - a surgery where AIS has gained popularity for maintaining visualization despite suction. This study was also powered to evaluate the effect of decreasing pneumoperitoneum by 20% in the valveless system.

MATERIALS AND METHODS

Three high-volume institutions randomized subjects into CIS 15, AIS 15, and AIS 12 mm Hg cohorts. Endpoints included rates of subcutaneous emphysema (SCE), pneumothorax (PTX), pneumomediastinum (PMS), intraoperative end-tidal carbon dioxide (ET CO₂), and peak airway pressure (PAP), as well as hospital stay, post-operative pain, and complications. Given the substantial proportion of retroperitoneal surgery, a secondary analysis evaluated the effect of surgical approach.

RESULTS

Two hundred and two patients were accrued. SCE was decreased in the AIS 12 mm Hg group (p=0.003). PTX and PMS rates were not statistically significantly different across the 3 insufflation groups. Higher rates of SCE and PMS, although not PTX, were noted in all retroperitoneal surgery groups - with lower SCE rates for AIS 12 mm Hg regardless of surgical approach.

CONCLUSION

AIS is often preferred for complex procedures including retroperitoneal and transperitoneal robotic-assisted partial nephrectomy, for its maintenance of pneumoperitoneum despite continuous suction necessary for visualization. This study shows that AIS is safe when compared to CIS at 15 mm Hg, and shows improvement in outcomes when pneumoperitoneum pressure is reduced by 20% to 12 mmHg.

Clinical and Organizational Impact of the AIRSEAL® Insufflation System During Laparoscopic Surgery: A Systematic Review

Several low-impact laparoscopic strategies have been developed to improve the safety of pneumoperitoneum. We conducted a systematic review to establish the current evidence base for the use of the AIRSEAL^® insufflation device for low-pressure pneumoperitoneum in laparoscopic surgery. We searched the literature using several electronic databases, for studies with comparative design published in the English language from January 2010 to April 2020. The population of interest included patients with any type of health condition who underwent laparoscopic surgery using the AIRSEAL^® insufflation system or a standard CO₂ insufflator. Ten studies (four randomized clinical trials/six non-randomized clinical trials), that enrolled 1394 participants in total who underwent urology, gynaecology or abdominal surgeries, were included. Total complication rates were similar between groups. Only three studies evaluated the impact of the insufflation system on post-operative pain, and showed inconsistent benefit of AIRSEAL^® (significant decrease in pain in two studies, no difference in one). The same was observed in the two sole studies in which pain killers consumption was measured (significant decrease in morphine consumption 24 h after surgery in one study, no difference in the other). Operative duration was significantly shorter with AIRSEAL^® in three studies. For both post-operative room and total length of stay, there was no difference between groups. No studies reported economic outcomes. Current literature supports the feasibility of the AIRSEAL^® system during laparoscopic surgery but more studies are required to establish the added clinical benefit and to explore the preferences of physicians and patients.

Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design

OBJECTIVE

To compare changes in microcirculation blood flow (MCBF) between pulsatile and continuous flow insufflation. Transanal total mesorectal excision (TaTME) was developed to improve the quality of the resection in rectal cancer surgery. The AirSeal IFS® insufflator facilitates the pelvic dissection, although evidence on the effects that continuous flow insufflation has on MCBF is scarce.

METHODS

Thirty-two pigs were randomly assigned to undergo a two-team TaTME procedure with continuous (n = 16) or pulsatile insufflation (n = 16). Each group was stratified according to two different pressure levels in both the abdominal and the transanal fields, 10 mmHg or 14 mmHg. A generalized estimating equations (GEE) model was used.

RESULTS

At an intra-abdominal pressure (IAP) of 10 mmHg, continuous insufflation was associated with a significantly lower MCBF reduction in colon mucosa [13% (IQR 11;14) vs. 21% (IQR 17;24) at 60 min], colon serosa [14% (IQR 9.2;18) vs. 25% (IQR 22;30) at 60 min], jejunal mucosa [13% (IQR 11;14) vs. 20% (IQR 20;22) at 60 min], renal cortex [18% (IQR 15;20) vs. 26% (IQR 26;29) at 60 min], and renal medulla [15% (IQR 11;20) vs. 20% (IQR 19;21) at 90 min]. At an IAP of 14 mmHg, MCBF in colon mucosa decreased 23% (IQR 14;27) in the continuous group and 28% (IQR 26;31) in the pulsatile group (p = 0.034).

CONCLUSION

TaTME using continuous flow insufflation was associated with a lower MCBF reduction in colon mucosa and serosa, jejunal mucosa, renal cortex, and renal medulla compared to pulsatile insufflation.

Prospective randomized controlled trial on comparison of standard CO2 pressure pneumoperitoneum insufflator versus AirSeal®

Background

AirSeal® is a valve-free insufflation system that enables a stable pneumoperitoneum with continuous smoke evacuation and CO₂ recirculation during laparoscopic surgery. Comparative evidence on the use of AirSeal® and standard CO₂ insufflator in laparoscopic general surgery procedures is scarce. The aim of this study was to compare surgical outcomes between AirSeal® and standard CO₂ insufflators in patients undergoing the most frequently performed laparoscopic procedures.

Methods

One hundred and ninety-eight patients undergoing elective laparoscopic cholecystectomy, colorectal surgery and hernia repair were randomized to either AirSeal® (group A) or standard pressure CO₂ insufflator (group S). The primary endpoints were operative time and level of postoperative shoulder tip pain (Visual Analog Scale). Secondary outcomes included Clavien–Dindo grade complications, surgical side effect and length of hospital stay.

Results

Patients were randomized to either group A (n = 101) or group S (n = 97) and were analyzed by intention-to-treat. There was no significant difference in mean operative time between the groups (median [IQR]; 71 min [56–94] in group A vs. 69 min [52–93] in group S; p = 0.434). Shoulder tip pain levels were significantly lower in group S (VAS 0 [0–3] in group S vs. 2 [0–4] in group A; p = 0.001). There was no significant difference in complications, surgical side effects (subcutaneous emphysema was not observed in any group) and length of hospital stay.

Conclusion

This randomized controlled trial showed that using the AirSeal® system did not reduce operative time and was associated with a higher postoperative shoulder tip pain compared to standard CO₂ insufflator for short elective surgeries.

ClinicalTrials.gov (NCT01740011).

Comparison of valve-less and standard insufflation on pneumoperitoneum-related complications in robotic partial nephrectomy: a prospective randomized trial

To prospectively compare standard and valve-less insufflation systems on pneumoperitoneum-related complications in robotic-assisted laparoscopic partial nephrectomy. A prospective randomized controlled trial was conducted during a 1.5-year period to compare insufflation-related complications in partial nephrectomy surgery by a single surgeon. Thirty-one patients were recruited for each group: AirSeal insufflation system at 12 mmHg (AIS12), AirSeal at 15 mmHg (AIS15), and conventional insufflation system at 15 mmHg (CIS). Primary outcome assessed was rate of subcutaneous emphysema. Secondary outcomes included rates of pneumothorax, pneumomediastinum, shoulder pain scores, overall pain scores, pain medication usage, insufflation time, recovery room time, length of hospital stay and impact of surgical approach. Predictors for subcutaneous emphysema were assessed with univariate and multivariate logistic models. 93 patients with similar baseline characteristics were randomized into the three insufflation groups. Incidence of subcutaneous emphysema was lower in the AIS12 group compared to CIS (19% vs 48%, p = 0.03,). Mean pain score was less for AIS12 compared to CIS at 12 h (3.1 vs 4.4, p = 0.03). Shoulder pain was less in AIS12 and AIS15 groups compared to CIS at 8 h (AIS12 vs CIS: 0.6 vs 1.6, p = 0.01, AIS15 vs CIS: 0.6 vs 1.6, p = 0.02), and between AIS12 as compared to CIS at 12 h (0.4 vs 1.4, p = 0.003) postoperatively. There was no difference between morphine equivalent use, insufflation time, recovery room time, and length of hospital stay. Multivariable regression analysis showed AirSeal at 12 mmHg and the transperitoneal approach to be the only significant predictors for lower risk of developing subcutaneous emphysema (p < 0.001). Compared to standard insufflation, AirSeal insufflation at 12 mmHg was associated with reduced risk of developing subcutaneous emphysema in robotic partial nephrectomy. Furthermore, shoulder pain was reduced in both AirSeal groups compared to standard insufflation. The retroperitoneal approach increases the risk of developing subcutaneous emphysema.

Laparoscopy during the COVID-19 Pandemic: Absence of Evidence is not Evidence of Absence

From a local outbreak to a global pandemic, the severe acute respiratory syndrome-coronavirus-2 infection has spread across 210 borders to infect 2.5 million humans. There is an organized disruption in the routine hospital functioning to divert the available resources for effective crisis management; most of the departments have been split to carve out a "COVID task force." The recommended indications for treatment of various medical conditions, medical procedures, and protocols have regressed on the evolutionary timeline. Newer recommendations are being released and updated regularly based on emerging evidence and experts' opinions. In view of exponential spread of the virus through routes already identified or those still elusive, the shedding of the virus during the incubation period, and lack of scientific evidence, the questions of "laparoscopy" or "no laparoscopy" assume importance. Herein, the evidence in literature pertaining to patient safety, efficient and effective utilization of hospital resources, and safety of health-care workers (HCWs) during the pandemic have been reviewed from the perspective of laparoscopy. The pathobiology of the virus including its survival properties and the different modes of transmission has been highlighted, and the relative risk to the HCWs between open and laparoscopic surgery dwelt upon. The recommendations from various international bodies have been discussed. Notwithstanding the absence of concrete evidence to exclude the possibility of bioaerosol-based transmission of the disease to the operating room staff, there is a multitude of other concerns which are addressed by avoiding the use of the laparoscope in the current scenario. Moreover, the absence of evidence is not evidence of absence; considering the high contagion and a long latent period associated with this virus, the onus is upon each individual surgeon to decide if one needs evidence of bioaerosol-based transmission or evidence in favor of safety before taking up 'laparoscopy' against 'open surgery'.

Anatomical Considerations and Procedure-Specific Aspects Important in Preventing Operative Morbidity during Transanal Total Mesorectal Excision

As transanal total mesorectal excision (taTME) becomes increasingly utilized, its technical challenges and potential pitfalls have become more clearly appreciated. This chapter explores the differences in how anatomy presents itself from the taTME vantage point as compared with traditional approaches to taTME, and how special problems unique to taTME pose a new set of operative challenges. Morbidity related, specifically, to the technique of taTME is also delineated with particular focus on male urethral injury.

Operative vectors, anatomic distortion, fluid dynamics and the inherent effects of pneumatic insufflation encountered during transanal total mesorectal excision

BACKGROUND

Transanal total mesorectal excision (taTME) is an altogether different approach to rectal cancer surgery, and the effects of carbon dioxide (CO₂) on this dissection remain poorly described.

METHODS

This article critically examines the effect of carbon dioxide insufflation and the workspace it creates during the process of taTME. The unique aspects of insulation with this approach are governed by the laws of physics, especially the principles of fluid dynamics, an area that remains poorly described for laparoscopy and not at all described for taTME.

RESULTS

A summary of established factors which affect the operative field of the taTME surgeon is delineated and further explored. In addition, new concepts regarding gas delivery, such as insufflation vectors, anatomic distortion, hyper-dissection, and workspace volume rate of change as a function of taTME dissection time, are addressed. Collectively, these factors pose important challenges which increase case complexity and are thus essential for taTME trainers and trainees alike to understand.

CONCLUSIONS

Although an invisible gas, CO₂ insufflation with taTME produces markedly visible effects which are imposed upon the operative field. This can result in anatomic distortion and misperception of operative planes. Thus, practicing taTME surgeons should be cognizant of these effects.

Pneumothorax After Laparoscopic Robotic-Assisted Supracervical Hysterectomy and Sacrocolpopexy

We present a case of a patient in whom subcutaneous emphysema, pneumoperitoneum, and pneumothorax occurred on postoperative day 1 after robotic-assisted supracervical hysterectomy, bilateral salpingectomy, sacrocolpopexy, and retropubic midurethral sling placement for pelvic organ prolapse and stress urinary incontinence. This case demonstrates a rare complication of gynecologic laparoscopic procedures.

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.

Pneumoperitoneum and hemodynamic stability during pediatric laparoscopic appendectomy

BACKGROUND

Conventional pneumoperitoneum (CP) and automatically maintained pneumoperitoneum using AirSeal Intelligent Flow System (AiFS) were compared during pediatric laparoscopic appendectomy (LA) using intraperitoneal pressure (IPP) and hemodynamic parameters.

METHODS

A prospective review of 39 children aged 3-14years who had standard 3-trocar LA was performed. Pneumoperitoneum was either AiFS (n=18) or CP (n=21) according to the surgeon's preference. IPP during insertion of trocars in all subjects was initially 8-10mmHg, which was reduced to 5mmHg then maintained until LA was completed. Data were collected every 5min during pneumoperitoneum.

RESULTS

Subject demographics were similar for both groups. During pneumoperitoneum, average IPP (AiFS: 7.9; CP: 9.0mmHg), average systolic blood pressure (AiFS: 100.4; CP: 106.9mmHg), and average end-tidal CO₂ (EtCO₂; AiFS: 35.7; CP: 38.5mmHg) were significantly different (p<.05, respectively), while pulse (AiFS: 92.1; CP: 96.4bpm), oxygen saturation (AiFS: 98.8; CP: 98.8%), body temperature (AiFS: 37.2; CP: 37.4), urine output (AiFS: 2.7; CP: 2.4mL/kg per hour), operative time (AiFS: 72.2; CP: 76.2mins), blood loss (AiFS: 3.6; CP: 3.5mL), recommencement of oral intake (AiFS: 1.3; CP: 1.4days), and postoperative hospitalization (AiFS: 4.3; CP: 3.8days) were not.

CONCLUSION

Because IPP was significantly lower during LA with AiFS, EtCO₂ and BP were significantly lower.

LEVEL OF EVIDENCE

Treatment study; prospective comparative study - level II.

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.

Advances in laparoscopic surgery in urology

In the past 10 years, laparoscopy has been challenged by robotic surgery; nevertheless, laparoscopic techniques are subject to continuous change. Ultrahigh definition is the next development in video technology, it delivers fourfold more detail than full high definition resulting in improved fine detail, increased texture, and an almost photographic emulsion of smoothness of the image. New 4K ultrahigh-definition technology might remove the current need for the use of polarized glasses. New devices for laparoscopy include advanced sealing devices, instruments with six degrees of freedom, ergonomic platforms with armrests and a chest support, and camera holders. A manually manipulated robot-like device is still at the experimental stage. Robot-assisted surgery has substantially revolutionized laparoscopy, increasing its distribution; however, robot-assisted surgery is associated with considerable costs. All technical improvements of laparoscopic surgery are extremely valuable to further simplify the use of classical laparoscopy.

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.

Optimal dissection for transanal total mesorectal excision using modified CO2 insufflation and smoke extraction

AIM

The new approach of transanal total mesorectal excision is technically challenging and demands a stable field of dissection with optimal view of anatomical landmarks. We aimed to describe and demonstrate a modification of both the insufflation of carbon dioxide and smoke evacuation, in order to optimize dissection.

METHOD

The comparison of standard insufflation to an AirSeal platform demonstrates a clear difference. This is shown in the accompanying video-recordings.

RESULTS

A more stable pneumorectum and better smoke evacuation as well as more convenient and precise dissection were achieved with the AirSeal platform.

CONCLUSION

Using the technique outlined, the operating surgeon is able to perform the surgical dissection in a stable operating environment with increased visibility compared to the standard approach.

In-vitro investigations on laser-induced smoke generation mimicking the laparoscopic laser surgery purposes

Intraoperative smoke-generation limits the quality of vision during laparoscopic/endoscopic laser-assisted surgeries. The current study aimed at the evaluation of factors affecting this phenomenon. As a first step, a suitable experimental setup and a test tissue model were established for this investigation. The experimental setup is composed of a specific sample container, a laser therapy component suitable for the ablation of model tissue at different treatment wavelengths (λ = 980 nm, 1350 nm, 1470 nm), a suction unit providing continuous smoke extraction, and a detection unit for smoke quantification via detection of light (λ = 633 nm) scattered from smoke particles. The ablation rate (AR) was calculated by dividing the ablated volume by the ablation time (60 sec). The laser-induced scattering signal intensity of the smoke (SI) was determined from time-charts of the signal intensity as a measure for vision, in addition a delay-time tdelay could be derived defining the onset of SI after the laser was switched on. The ratio SI/AR is used as a measure for smoke generation in relation to the ablation rate. Additionally the light transmission of the tissue samples was used to estimate their optical properties. In this set-up, smoke generation using λ = 980 nm as ablation laser wavelength was detected after a delay-time tdelay = (121.6 ± 24.8) sec which is significantly longer compared to the wavelengths λ = 1350 nm with tdelay = (89.8 ± 19.3) sec and λ = 1470 nm with tdelay = (24.7 ± 5.4) sec. Thus, the delay Experimental set-up consisting of sample container, laser therapy component, suction unit and scattered-light detection compartment. time is wavelength-dependent. The SI/AR ratio was significantly different (p < 0.001) for 1470 nm irradiation compared to 980 nm irradiation [SI/AR(1470) = (11.8 ± 2.6) · 10(3) vs. SI/AR(980) = (8.6 ± 2.0) · 10(3) ]. The ablation crater for 980 nm irradiation was comparable with 1470 nm irradiation, but the coagulation rim was thicker in the 980 nm case. In conclusion, it could be shown experimentally that smoke-generation depends on the wavelength used for laser ablation.

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.

AirSeal system insufflator to maintain a stable pneumorectum during TAMIS

Transanal minimally invasive surgery (TAMIS) is typically used for treating intraluminal rectal tumors. Other applications have recently been described. We here present the use of TAMIS as a tool to treat a chronic anastomotic fistula after restorative rectal resection. A new insufflation device expected to solve the problem of maintaining a stable pneumorectum is described.

LESS and NOTES instrumentation: future

PURPOSE OF REVIEW

Laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) are novel techniques with potential to minimize the morbidity of surgery. Challenging ergonomics, instrument clashing, and the lack of true triangluation still remain great concerns.

RECENT FINDINGS

New technological developments in instrument design have been created to enhance clinical applicability of these techniques. Further technological advancements including the incorporation of novel robotic surgical platforms (R-LESS) exploit the ergonomic benefits in an attempt to further advance LESS surgery. Promising devices include magnetic anchoring and guidance systems that have the potential to allow external manoeuvring of intracorporeal instruments while facilitating triangulation and reducing clashing. As well, the benefit of miniature in-vivo robots that can be placed endoscopically intra-abdominally and controlled wirelessly will allow internal manipulation of tissue from internal repositionable platforms.

SUMMARY

It remains to be seen whether LESS or NOTES will prove their clinical benefit over standard laparoscopic or robotic procedures. In this chapter, we review the current LESS and NOTES technology, and focus on new innovations and research in the field.

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.