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.

Impact of the combination of abdominal peripheral nerve block and neuromuscular blockade on the surgical space during robot-assisted laparoscopic surgery: a prospective randomized controlled study.

PURPOSE: The impact of the combination of abdominal peripheral nerve block (PNB) and the depth of neuromuscular blockade on the surgical field were assessed. METHODS: Thirty-eight patients undergoing elective robot-assisted laparoscopic radical prostatectomy (RARP) were randomized into two groups: a PNB group (moderate neuromuscular block [train-of-four 1-3 twitches] with abdominal PNB) and a non-PNB group (deep neuromuscular block [post-tetanic count 0-2 twitches] without abdominal PNB). The primary outcome was the change in the depth of the abdominal cavity relaxation assessed by the change in the distance (Δdistance) between the umbilicus port and peritoneum upon pneumoperitoneal pressure increase from 8 to 12 mmHg. The secondary outcomes were the CO2 usage for the pneumoperitoneal pressure increase and the subjective differences in the Surgical Rating Score (SRS) during surgery. RESULTS: The Δdistance and the CO2 usage from 8 to 12 mmHg did not differ significantly between the non-PNB and PNB groups (1.34 ± 0.65 vs. 1.28 ± 0.61 cm, p = 0.763 and 3.64 ± 1.68 vs. 4.34 ± 1.44 L, p = 0.180, respectively). There was also no significant difference in SRS. Comparisons of the Δdistance values for pressure increases from 6 to 8 mmHg, 6 to 10 mmHg and 6 to 12 mmHg between the non-PNB and PNB groups also showed no between-group differences, despite significant intra-group differences (p < 0.001) by pressure increment. CONCLUSIONS: Our findings indicate that moderate neuromuscular block with abdominal PNB maintained an adequate surgical space for RARP, with no significant difference from the space achieved by deep neuromuscular block.

Prospective, randomized, clinical trial on the effects of laparoscopic insufflation pressures on portal pressures in dogs.

OBJECTIVE: The adverse effects of intra-abdominal pressure from capnoperitoneum on cardiovascular and pulmonary systems have been well documented, but the effects on portal pressures in dogs with various insufflation pressures is poorly defined. The aim of the present study was to measure the effect of a range of insufflation pressures on the portal pressure, using direct pressure measurements in patients undergoing laparoscopy. STUDY DESIGN: Clinical randomized prospective study. ANIMALS: Nine client-owned dogs undergoing routine laparoscopy. METHODS: Two rounds of direct portal pressure assessments were performed, at insufflation pressures of 0, 6, 10, and 14 mmHg in a predetermined randomized sequence. The data were analyzed for effects of insufflation pressure, hemodynamic alterations, and round. A best-fit exponential model of the relationship between portal pressure and insufflation pressure was created. RESULTS: Portal pressure increased by 38% at 6 mmHg, 95% at 10 mmHg, and 175% at 14 mmHg compared to baseline. Portal pressure increased at an average rate of 7.45% per mmHg of insufflation pressure. Effects of weight, weight/insufflation pressure interaction, and round of insufflation were not statistically significant. No systemic hemodynamic adverse events were observed. CONCLUSION: Portal pressure increased as insufflation pressure increased. There was no clinically significant difference in baseline portal pressure between rounds of insufflation. CLINICAL SIGNIFICANCE: This exponential model of portal pressure supports the use of the minimum insufflation pressure to allow visualization during laparoscopy. The return of portal pressure to baseline following desufflation supports the comparison of portal pressure measurements before and after laparoscopic shunt attenuation.

Low-pressure pneumoperitoneum with deep neuromuscular blockade versus standard pressure pneumoperitoneum in patients undergoing laparoscopic cholecystectomy for gallstone disease: a non-inferiority randomized control trial.

BACKGROUND: Low-pressure pneumoperitoneum (LPP) is an attempt at improving laparoscopic surgery. However, it has the issue of poor working space for which deep neuromuscular blockade (NMB) may be a solution. There is a lack of literature comparing LPP with deep NMB to standard pressure pneumoperitoneum (SPP) with moderate NMB. METHODOLOGY: This was a single institutional prospective non-inferiority RCT, with permuted block randomization of subjects into group A and B [Group A: LPP; 8-10 mmHg with deep NMB [ Train of Four count (TOF): 0, Post Tetanic Count (PTC): 1-2] and Group B: SPP; 12-14 mmHg with moderate NMB]. The level of NMB was monitored with neuromuscular monitor with TOF count and PTC. Cisatracurium infusion was used for continuous deep NMB in group A. Primary outcome measures were the surgeon satisfaction score and the time for completion of the procedure. Secondarily important clinical outcomes were also reported. RESULTS: Of the 222 patients screened, 181 participants were enrolled [F: 138 (76.2%); M: 43 (23.8%); Group A n = 90, Group B n = 91]. Statistically similar surgeon satisfaction scores (26.1 ± 3.7 vs 26.4 ± 3.4; p = 0.52) and time for completion (55.2 ± 23.4 vs 52.5 ± 24.9 min; p = 0.46) were noted respectively in groups A and B. On both intention-to-treat and per-protocol analysis it was found that group A was non-inferior to group B in terms of total surgeon satisfaction score, however, non-inferiority was not proven for time for completion of surgery. Mean pain scores and incidence of shoulder pain were statistically similar up-to 7 days of follow-up in both groups. 4 (4.4%) patients in group B and 2 (2.2%) in group A had bradycardia (p = 0.4). Four (4.4%) cases of group A were converted to group B. One case of group B converted to open surgery. Bile spills and gallbladder perforations were comparable. CONCLUSION: LPP with deep NMB is non-inferior to SPP with moderate NMB in terms of surgeon satisfaction score but not in terms of time required to complete the procedure. Clinical outcomes and safety profile are similar in both groups. However, it could be marginally costlier to use LPP with deep NMB.

Impact of Standard Versus Low Pneumoperitoneum Pressure on Peritoneal Environment in Laparoscopic Cholecystectomy. Randomized Clinical Trial.

BACKGROUND: High CO 2 pneumoperitoneum pressure during laparoscopy adversely affects the peritoneal environment. This study hypothesized that low pneumoperitoneum pressure may be linked to less peritoneal damage and possibly to better clinical outcomes. MATERIALS AND METHODS: One hundred patients undergoing scheduled laparoscopic cholecystectomy were randomized 1:1 to low or to standard pneumoperitoneum pressure. Peritoneal biopsies were performed at baseline time and 1 hour after peritoneum insufflation in all patients. The primary outcome was peritoneal remodeling biomarkers and apoptotic index. Secondary outcomes included biomarker differences at the studied times and some clinical variables such as length of hospital stay, and quality and safety issues related to the procedure. RESULTS: Peritoneal IL6 after 1 hour of surgery was significantly higher in the standard than in the low-pressure group (4.26±1.34 vs. 3.24±1.21; P =0.001). On the contrary, levels of connective tissue growth factor and plasminogen activator inhibitor-I were higher in the low-pressure group (0.89±0.61 vs. 0.61±0.84; P =0.025, and 0.74±0.89 vs. 0.24±1.15; P =0.028, respectively). Regarding apoptotic index, similar levels were found in both groups and were 44.0±10.9 and 42.5±17.8 in low and standard pressure groups, respectively. None of the secondary outcomes showed differences between the 2 groups. CONCLUSIONS: Peritoneal inflammation after laparoscopic cholecystectomy is higher when surgery is performed under standard pressure. Adhesion formation seems to be less in this group. The majority of patients undergoing surgery under low pressure were operated under optimal workspace conditions, regardless of the surgeon's expertise.

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.

Effect of low-pressure pneumoperitoneum on pain and inflammation in laparoscopic cholecystectomy: a randomized controlled clinical trial.

OBJECTIVE: We aim to assess the effect of low-pressure pneumoperitoneum on post operative pain and ten of the known inflammatory markers. BACKGROUND: The standard of care pneumoperitoneum set pressure in laparoscopic cholecystectomy is set to 12-14 mmHg, but many societies advocate to operate at the lowest pressure allowing adequate exposure of the operative field. Many trials have described the benefits of operating at a low-pressure pneumoperitoneum in terms of lower post operative pain, and better hemodynamic stability. But only few describe the effects on inflammatory markers and cytokines. METHODS: A prospective, double-blinded, randomised, controlled clinical trial, including patients who underwent elective laparoscopic cholecystectomy. Patients randomised into low-pressure (8-10 mmHg) vs. standard-pressure (12-14 mmHg) with an allocation ratio of 1:1. Perioperative variables were collected and analysed. RESULTS: one hundred patients were allocated, 50 patients in each study arm. Low-pressure patients reported lower median pain score 6-hour post operatively (5 vs. 6, p-value = 0.021) in comparison with standard-pressure group. Eight out of 10 inflammatory markers demonstrated better results in low-pressure group in comparison with standard-pressure, but the effect was not statistically significant. Total operative time and surgery difficulty was not significantly different between the two groups even in the hands of inexperienced surgeons. CONCLUSION: low-pressure laparoscopic cholecystectomy is associated with less post operative pain and lower rise of inflammatory markers. It is feasible with comparable complications to the standard of care. Registered on ClinicalTrials.gov (NCT05530564/ September 7th, 2022).

Effect of duration of pneumoperitoneum on renal function in patients undergoing laparoscopic surgeries: a prospective observational study.

This study aimed to assess the effect of pneumoperitoneum and, thereby, raised intra-abdominal pressure for different durations (≤ 1 h, 1-3 h and > 3 h) on renal function. One hundred and twenty adult patients were allocated to four groups-the Control Group A (N = 30; patients undergoing non-laparoscopic surgery) or Group B (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum < 1 h) or Group C (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum 1-3 h) or Group D (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum > 3 h). The baseline, intraoperative (at the end of pneumoperitoneum/surgery), and postoperative (after 6 h) values of blood urea levels, creatinine clearance, and serum cystatin C were compared. The results showed that the raised IAP (10-12 mmHg) and varying durations of pneumoperitoneum (from less than 1 h to more than 3 h) did not significantly affect renal function measured in terms of change in serum cystatin levels from baseline to 6 h in postoperative period. The varying durations of pneumoperitoneum also did not significantly affect serum creatinine or blood urea levels in the postoperative period. CTRI registration: CTRI/2016/10/007334.

Botulinum toxin A (IncobotulinumtoxinA) and pneumoperitoneum image-guided for hernia repair with loss of dominance.

Post-incisional ventral hernia is estimated at 5-30%, when the content of the abdominal cavity migrates to the hernial sac (HSV), with a HSV/abdominal cavity volume ratio > 25%, conditioning systemic changes defined as "loss of domain". A 27-year-old male presented with ventral hernia with loss of domain that required pre-operative preparation techniques, using application of botulinum toxin A (IncobotulinumtoxinA) and pneumoperitoneum, both guided by image. A ventral plasty was performed with adequate return of the viscera to the abdominal cavity. The combination of both techniques seems to be a safe procedure to carry out a tension-free repair.

La hernia ventral postincisional se estima en 5 al 30%, cuando el contenido de la cavidad abdominal migra al saco herniario, con una relación VSH/VCA > 25% condicionando cambios sistémicos se define como "pérdida de dominio". Masculino de 27 años con hernia ventral con pérdida de dominio que ameritó técnicas de preparación preoperatoria, utilizando toxina botulínica A (IncobotulinumtoxinA) y neumoperitoneo, ambos guíados por imagen. Se realizó una plastia ventral con adecuado regreso de las vísceras a la cavidad abdominal. La combinación de ambas técnicas es un procedimiento seguro para realizar una reparación libre de tensión.

Impact of pneumoperitoneum pressure during laparoscopic hysterectomy: A randomized controlled trial.

OBJECTIVE: Minimally invasive hysterectomy is a commonly performed gynecologic procedure with associated postoperative pain managed with opioid medications. Uncontrolled postoperative pain leads to increased opioid use/abuse, longer hospital stays, increase in healthcare visits, and may negatively affect patient satisfaction. Current data suggests that reduced pneumoperitoneum insufflation pressure during laparoscopic surgery may impact postoperative pain. Given the current opioid epidemic, surgeons are proactively finding ways to reduce postoperative pain. It is unclear how reduced pneumoperitoneum pressure impacts the surgeon. We investigated the impact of reduced pneumoperitoneum insufflation pressure on surgeon satisfaction. STUDY DESIGN: This was a pilot, double-blinded, randomized controlled trial from March 2020 to July 2021 comparing pneumoperitoneum pressure of 15 mmHg to reduced pressures of 12 mmHg and 10 mmHg during laparoscopic hysterectomy. RESULTS: A total of 40 patients were randomized (13 - 15 mmHg, 13 - 12 mmHg, and 14 - 10 mmHg). The primary outcome was surgeon satisfaction. Secondary outcomes included patient satisfaction, operative time, blood loss, postoperative pain, opioid usage, and discharge timing. There were no differences in baseline demographics or perioperative characteristics. Surgeon satisfaction was negatively impacted with lower pneumoperitoneum pressures greatest with 10 mmHg, including overall satisfaction (p =.01), overall effect of the pneumoperitoneum (p =.04), and quality of visualization (p =.01). There was an apparent although not statistically significant difference in operative time (p =.06) and blood loss (p =.054). There was no difference in patient satisfaction, postoperative pain scores, opioid usage, or time to discharge. CONCLUSION(S): Reduced pneumoperitoneum insufflation pressure during laparoscopic hysterectomy negatively impacted surgeon satisfaction with a trend towards longer operative times and greater blood loss, and did not positively impact patient satisfaction, postoperative pain, opioid demand, or discharge timing.

Comparison of the effect of general anesthesia and spinal anesthesia technique combined with general anesthesia on intraabdominal volume during gynecological laparoscopy.

PURPOSE: We aimed to investigate the effect of spinal anesthesia which will be performed simultaneously with general anesthesia on the site of operation with the same pressure. MATERIAL AND METHOD: This study was conducted as a randomized, prospective clinical study on 40 patients who were randomly divided into two groups. Twenty women underwent general anesthesia (Group GA) and 20 women underwent spinal anesthesia with general anesthesia (Group SGA). For all cases, preoperative height, weight, waist circumference, body mass index (kg/m2 ), the distance between both spina iliaca anterior superior, the distance of the intersection of both ribs with an imaginary line drawn over the anterior axillary line, suprapubic bone-umbilical, umbilical-xiphoid, and suprapubic bone-xiphoid distance from the midline of the abdomen were measured. Moreover, while the patient was lying in the neutral position on the operating table, the height of the highest point of the abdomen to the operating table was also measured. These measurements were repeated at intra-abdominal pressure (IAP) 14 and 25 mmHg. The amount of intra-abdominal insufflated CO2 was also recorded at IAP 14 and 25 mmHg. RESULTS: When the intra-abdominal insufflation volumes of both groups were compared at 14 and 25 mmHg, respectively, there was no statistical difference (p: 0.54, p: 0.40). When 14 and 25 mmHg were compared in all cases, a statistically significant difference was observed in other measurements except in xiphoid-umbilical distance (p < 0.05). CONCLUSION: We found that spinal anesthesia combined with GA had no effect on the abdominal volume and anthropometric measurements in laparoscopic procedures.

Assessment of laparoscopic working space in guinea pigs (Cavia porcellus) undergoing carbon dioxide insufflation at different intra-abdominal pressures.

OBJECTIVE: To evaluate pneumoperitoneal volumes (laparoscopic working space) in guinea pigs (Cavia porcellus) undergoing pneumoperitoneum via carbon dioxide insufflation at different intra-abdominal pressures (IAPs) (4, 6, and 8 mm Hg) and recumbencies (dorsal, right lateral, and left lateral). ANIMALS: Six 3- to 4-month-old sexually intact female Hartley guinea pigs. PROCEDURES: Guinea pigs were anesthetized, intubated, and had an abdominal insufflation catheter placed. A baseline abdominal CT scan was performed. Guinea pigs underwent insufflation, with each IAP given in a random order for 10 to 15 minutes with a washout period of 5 minutes between pressures. Abdominal CT scans were acquired at each IAP and at each recumbency. Pneumoperitoneal volumes were calculated using software. RESULTS: Increases in IAP increased working space significantly (P < .001). The 6- and 8-mm Hg pressures increased working space from 4 mm Hg by 7.3% and 19.8%, respectively. Recumbent positioning (P = .60) and body weight (P = .73) did not affect working space. Order of IAP had a significant (P = .006) effect on working space. One of the guinea pigs experienced oxygen desaturation and bradycardia at 6- and 8-mm Hg IAP. CLINICAL RELEVANCE: Although an increased working space occurred at 6 and 8 mm Hg compared to 4 mm Hg, further research is needed concerning the cardiovascular effects of pneumoperitoneum in guinea pigs to determine whether those higher IAPs are safe in this species. An IAP of 6 mm Hg can be considered for laparoscopic cannula placement, followed by a lower IAP for laparoscopic procedures.

A novel method for monitoring abdominal compliance to optimize insufflation pressure during laparoscopy.

BACKGROUND: Abdominal compliance describes the ease of expansion of the abdominal cavity. Several studies highlighted the importance of monitoring abdominal compliance (Cab) during the creation of laparoscopic workspace to individualize the insufflation pressure. The lack of validated clinical monitoring tools for abdominal compliance prevents accurate tailoring of insufflation pressure. Oscillometry, also known as the forced oscillation technique (FOT), is currently used to measure respiratory mechanics and has the potential to be adapted for monitoring abdominal compliance. This study aimed to define, develop and evaluate a novel approach which can monitor abdominal compliance during laparoscopy using endoscopic oscillometry. MATERIALS AND METHODS: Endoscopic oscillometry was evaluated in a porcine model for laparoscopy. A custom-built insufflator was developed for applying an oscillatory pressure signal superimposed onto a mean intra-abdominal pressure. This insufflator was used to measure the abdominal compliance at insufflation pressures ranging from 5 to 20 hPa (3.75 to 15 mmHg). The measurements were compared to the static abdominal compliance, which was measured simultaneously with computed tomography imaging. RESULTS: Endoscopic oscillometry recordings and CT images were obtained in 10 subjects, resulting in 76 measurement pairs for analysis. The measured dynamic Cab ranged between 0.0216 and 0.261 L/hPa while the static Cab based on the CT imaging ranged between 0.0318 and 0.364 L/hPa. The correlation showed a polynomial relation and the adjusted R-squared was 97.1%. CONCLUSIONS: Endoscopic oscillometry can be used to monitor changes in abdominal compliance during laparoscopic surgery, which was demonstrated in this study with a comparison with CT imaging in a porcine laparoscopy model. Use of this technology to personalize the insufflation pressure could reduce the risk of applying excessive pressure and limit the drawbacks of insufflation.

Accidental peritoneum-cutaneous fistula after insufflation of preoperative progressive pneumoperitoneum in a large incisional hernia with loss of domain.

Preoperative progressive pneumoperitoneum has represented an important advancement in achieving the reintroduction of large herniated volumes into the abdominal cavity. However, this technique is not free of complications. We present a case of a man in his 70s with an accidental peritoneal-cutaneous fistula, secondary to the excessive pressure of the pneumoperitoneum, during the preparation of a large incisional hernia with loss of domain intervention.

Active aspiration versus simple compression to remove residual gas from the abdominal cavity after laparoscopic cholecystectomy: a randomized clinical trial.

PURPOSE: After laparoscopic surgical procedures, residual gas in the abdominal cavity can cause post-operative pain, which is commonly located in the shoulder region. Previous studies suggested that post-laparoscopy pain can be prevented by active suctioning of intraabdominal gas at the end of surgery. METHODS: This randomized controlled trial (registered at DRKS 00,023,286) compared active suctioning versus manual compression in their ability to reduce pain after laparoscopic cholecystectomy. Patients scheduled for laparoscopic cholecystectomy were eligible for trial participation. The primary outcome measure was post-operative pain intensity after 12 h. All the patients were examined by MRI scanning to quantify the intraabdominal gas volume after the intervention. RESULTS: As planned, 60 patients were recruited. The two groups (n = 30 each) were very similar at the end of surgery. Active suctioning reduced the amount of residual pneumoperitoneum more than simple compression (median volume 1.5 versus 3.0 ml, p = 0.002). The primary outcome measure, abdominal pain after 12 h, was slightly lower in the intervention group (- 0.5 points, 95% confidence interval + 0.5 to - 1.7), but without reaching statistical significance (p = 0.37). After 12 h, shoulder pain was present in 10 patients in each group (p = 1.0). Independent of group assignment, however, residual gas volume was significantly associated with higher pain intensity. CONCLUSIONS: Active suctioning appears to have only a minor preventive effect on post-laparoscopy pain, probably because evacuation of the pneumoperitoneum remains incomplete in some patients. Other more effective maneuvers for gas removal should be preferred.

Review of Outcomes of Low Verses Standard Pressure Pneumoperitoneum in Laparoscopic Surgery.

BACKGROUND: Carbon dioxide pneumoperitoneum during laparoscopy changes cardiorespiratory physiology and contributes to post-op pain. We studied outcomes before and after implementing low-pressure pneumoperitoneum QI project. METHODS: Forty-two patients were insufflated at standard pressures (15 mmHg) while 41 were insufflated using low (8-12 mmHg) during laparoscopic procedures. These variables were obtained from the patient chart: pain scores, intravenous morphine milligram equivalents (MME), peak inspiratory pressures (PIP), end-tidal CO2 (EtCO2), surgery duration, and patient demographics. The study was conducted after IRB approval. RESULTS: Low-pressure pneumoperitoneum is feasible and the surgeon can increase to 10-12 mmHg as needed. The mean post-op IV MME was significantly decreased in the low-pressure group (11.75 ± 10.41) compared to the standard pressure group (17.36 ± 18.1) (t-test, P = .047). Mean peak inspiratory pressures during insufflation were significantly higher for procedures conducted at standard pressure (31.40 ± 4.82) compared to the 8 mmHg (24.68 ± 4.19) and 12 mmHg (27.33± 3.85) low pressure groups (one-way ANOVA, P < .0001). During insufflation, there was a significant increase in the average EtCO2 in the standard pressure group (42.07 ± 5.60) compared to the 8 mmHg low pressure group (37.59 ± 5.05) (ANOVA, P = .0096). Constant flow insufflation was more likely to be performed at low pressure than demand mode (58% v. 33%). CONCLUSION: Low pressure pneumoperitoneum decreases PIP pressure and CO2 absorption evidenced by lower ETCO2 intra-operatively. Patients have significant improvement in postoperative pain evidenced by decreased narcotics needed. Low pressure pneumoperitoneum using a constant flow insufflator is safe and results in improved patient outcomes.

Low-pressure versus standard-pressure pneumoperitoneum in laparoscopic cholecystectomy: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: It has been previously demonstrated that the rise of intra-abdominal pressures and prolonged exposure to such pressures can produce changes in the cardiovascular and pulmonary dynamic which, though potentially well tolerated in the majority of healthy patients with adequate cardiopulmonary reserve, may be less well tolerated when cardiopulmonary reserve is poor. Nevertheless, theoretically lowering intra-abdominal pressure could reduce the impact of pneumoperitoneum on the blood circulation of intra-abdominal organs as well as cardiopulmonary function. However, the evidence remains weak, and as such, the debate remains unresolved. The aim of this systematic review and meta-analysis was to demonstrate the current knowledge around the effect of pneumoperitoneum at different pressures levels during laparoscopic cholecystectomy. MATERIALS AND METHODS: This systematic review and meta-analysis were reported according to the recommendations of the 2020 updated Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines, and the Cochrane handbook for systematic reviews of interventions. RESULTS: This systematic review and meta-analysis included 44 randomized controlled trials that compared different pressures of pneumoperitoneum in the setting of elective laparoscopic cholecystectomy. Length of hospital, conversion rate, and complications rate were not significantly different, whereas statistically significant differences were observed in post-operative pain and analgesic consumption. According to the GRADE criteria, overall quality of evidence was high for intra-operative bile spillage (critical outcome), overall complications (critical outcome), shoulder pain (critical outcome), and overall post-operative pain (critical outcome). Overall quality of evidence was moderate for conversion to open surgery (critical outcome), post-operative pain at 1 day (critical outcome), post-operative pain at 3 days (important outcome), and bleeding (critical outcome). Overall quality of evidence was low for operative time (important outcome), length of hospital stay (important outcome), post-operative pain at 12 h (critical outcome), and was very low for post-operative pain at 1 h (critical outcome), post-operative pain at 4 h (critical outcome), post-operative pain at 8 h (critical outcome), and post-operative pain at 2 days (critical outcome). CONCLUSIONS: This review allowed us to draw conclusive results from the use of low-pressure pneumoperitoneum with an adequate quality of evidence.

A negative pressure-based visualization technique for abdominal Veress needle insertion.

PURPOSE: Abdominal Veress needle insertion is commonly performed to generate a pneumoperitoneum during laparoscopy. Various safety tests are conducted to confirm accurate needle tip positioning into the abdominal cavity. However, these occasionally yield unclear results and do not help directly visualize the peritoneum puncture. We validated a negative pressure-based technique that helps instantly visualize the moment of the Veress needle entry into the abdominal cavity. METHODS: This study included 761 patients who underwent laparoscopic hernioplasty between 2003 and 2021 that entailed pneumoperitoneum creation using a Veress needle. They were divided into conventional technique (CON) and negative pressure visualization technique (NPV) groups. The patients were propensity score-matched (1:1) to minimize selection bias. To determine whether the technique gave a clear result to the surgeon and precisely informed the moment of entry, failed entry and emphysematous complications were compared between the groups. RESULTS: The propensity score-matching yielded 105 pairs in the matched CON and NPV groups. Failed entry did not occur in the NPV group, whereas it occurred in 8 patients (7.6%) in the CON group (p = 0.004). No patient experienced extraperitoneal emphysema in the matched NPV group, whereas 7 patients (6.7%) in the CON group did (p = 0.007). The groups did not differ in the incidence of omental or mesenteric emphysema. CONCLUSION: The NPV eliminated the incidence of failed entry and decreased the incidence of extraperitoneal emphysema, indicating that it could simply and adequately inform the moment of needle entry into the abdominal cavity.

Incisional Hernias with Loss of Abdominal Domain: A New Look to an Older Issue or the Elephant in the Living Room. Literature Review.

Incisional hernia (IH) is a postoperative defect of the abdominal wall through which the contents of the peritoneal cavity are externalized beneath the skin in a peritoneal sac. IH differs in anatomic complexity, but also in its associated comorbidities and surgical history. As IH enlarges, complications occur and these become part of its natural history. The goal of the study is to review the impact of loss of domain upon abdominal wall before and after abdominal wall reconstruction. The absence of anatomical and functional linea alba leads to a combination of muscular disturbances, chronic respiratory and gastrointestinal conditions, and psychosocial issues. The pathophysiological changes are also due to the decrease of the intra-abdominal pressure (IAP). During repair, the sudden reintroduction of the viscera into an unprepared cavity leads to a sudden increase in cavity volume and an increase in IAP with fatal pathophysiological implications. For an optimal repair, preoperatively, the abdominal wall must be augmented by achieving the following objectives: reducing the volume of the sac contents, optimizing compliance, enlargement of the container. At the same time, for the optimal repair, the following must be taken into account: increased knowledge about this condition to manage systemic and local changes, CT scan evaluation, monitoring IAP, plateau pressure (PP), and Positive End Expiratory Pressure (PEEP). In conclusion, the goals can be achieved by systemic optimization with a multidisciplinary team, using Preoperative Progressive Pneumoperitoneum (PPP) and/or Botox (BTX), and abdominal wall reconstruction through a mesh with augmented component separation technique.