Humidification during laparoscopic surgery: overview of the clinical benefits of using humidified gas during laparoscopic surgery

Post-radical hysterectomy ovarian torsion-A gynecological emergency: a case series

BACKGROUND

Ovarian torsion is a surgical emergency whereby the ovary twists, or torts, on its ligamentous support and potentially compromises vascular supply to both the ovary and Fallopian tube. It accounts for 2-3% of all acute gynecological emergencies, yet is a condition that is rarely reported to occur after hysterectomy. While it is well established that ovarian torsion can occur after laparoscopic hysterectomy, we report on the rare occurrence of ovarian torsion occurring post the supposedly preventative ovarian transposition suspension procedure or ovariopexy. This highlights that further evaluation of laparoscopic surgical techniques are required to prevent this exquisitely painful gynecological condition occurring postoperatively.

CASE PRESENTATION

We report two cases of ovarian torsion post-primary laparoscopic radical hysterectomy performed for cervical malignancy. Both patients were Caucasian, multiparous, premenopausal female patients, aged 37 and 39 years old. Ovarian transposition suspension was performed at the primary procedure to allow ovarian function to be preserved if the patient's required postoperative pelvic irradiation if surgically upstaged. Both patients underwent emergency laparoscopic detorsion, with one torsion due to reoccurrence of her cervical cancer.

CONCLUSIONS

Adnexal torsion is estimated to occur between 1% and 8% in post-hysterectomy cases. It can be a difficult to diagnose condition, with prudent history-taking, relevant investigations, and a low threshold to consider laparoscopy forming essential clinical acumen. Unfortunately, the suspension of the ovaries post-hysterectomy does not exclude future ovarian torsion. With rising rates of cervical cancer in premenopausal women, reportedly increasing by 37% in the 25-34 age range in the United Kingdom (National Cancer Registration and Analysis Service, Public Health England. 2021), further research is needed to improve techniques to allow for safe ovarian conservation for these patients while undergoing operative treatment of cervical cancer.

A new ex vivo model system to analyze factors affecting the integrity of fetal membranes in fetoscopic surgery

We developed an ex vivo model system to analyze the influence of relevant environmental and mechanical factors potentially affecting the integrity of fetal membranes during fetoscopic surgery. The set-up exposes amniochorion membranes to insufflation at predefined levels of gas pressure, flow, humidity, and temperature. Change in fetal membranes stiffness is quantified during the phase mimicking surgery through measurement of membranes' strain in response to cyclic overpressure. The trocar induced perforation creates a mechanical weakness whose stability is assessed by increasing the insufflation pressure until membrane rupture. Damage of the epithelial cells lining the amnion is assessed through live-dead staining. Initial experiments demonstrated the functionality of the new apparatus and the feasibility of the proposed protocols. Fetal membranes exposed to air with low humidity for approximately 1 h demonstrated significant embrittlement, while their mechanical integrity was maintained in case of gas insufflation at high humidity (air as well as CO2). Under dry circumstances, there was a significant rate of epithelial cell death. Separation of amnion and chorion in the region of the trocar site was visible in all experiments. This new model is a versatile platform for analyzing the mechanical, histological, and biological implications of fetoscopic surgery on fetal membranes.

Application value of machine learning models in predicting intraoperative hypothermia in laparoscopic surgery for polytrauma patients

BACKGROUND

Hypothermia during laparoscopic surgery in patients with multiple trauma is a significant concern owing to its potential complications. Machine learning models offer a promising approach to predict the occurrence of intraoperative hypothermia.

AIM

To investigate the value of machine learning model to predict hypothermia during laparoscopic surgery in patients with multiple trauma.

METHODS

This retrospective study enrolled 220 patients who were admitted with multiple injuries between June 2018 and December 2023. Of these, 154 patients were allocated to a training set and the remaining 66 were allocated to a validation set in a 7:3 ratio. In the training set, 53 cases experienced intraoperative hypothermia and 101 did not. Logistic regression analysis was used to construct a predictive model of intraoperative hypothermia in patients with polytrauma undergoing laparoscopic surgery. The area under the curve (AUC), sensitivity, and specificity were calculated.

RESULTS

Comparison of the hypothermia and non-hypothermia groups found significant differences in sex, age, baseline temperature, intraoperative temperature, duration of anesthesia, duration of surgery, intraoperative fluid infusion, crystalloid infusion, colloid infusion, and pneumoperitoneum volume (P < 0.05). Differences between other characteristics were not significant (P > 0.05). The results of the logistic regression analysis showed that age, baseline temperature, intraoperative temperature, duration of anesthesia, and duration of surgery were independent influencing factors for intraoperative hypothermia during laparoscopic surgery (P < 0.05). Calibration curve analysis showed good consistency between the predicted occurrence of intraoperative hypothermia and the actual occurrence (P > 0.05). The predictive model had AUCs of 0.850 and 0.829 for the training and validation sets, respectively.

CONCLUSION

Machine learning effectively predicted intraoperative hypothermia in polytrauma patients undergoing laparoscopic surgery, which improved surgical safety and patient recovery.

Prevention of peritoneal adhesions after gynecological surgery: a systematic review

IMPORTANCE

The formation of adhesions after gynecological surgery not only has detrimental impacts on those affected, including pain, obstruction, and infertility, but also imposes a high economic burden on healthcare systems worldwide.

OBJECTIVE

The aim of this review was to evaluate the adhesion prevention potential of all currently available adhesion barriers for gynecological surgery.

EVIDENCE ACQUISITION

We systematically searched MEDLINE and CENTRAL databases for randomized controlled trials (RCTs) on the use of adhesion barriers as compared with peritoneal irrigation or no treatment in gynecological surgery. Only RCTs with second-look surgery to evaluate adhesions in the pelvic/abdominal (but not intrauterine) cavity were included.

RESULTS

We included 45 RCTs with a total of 4,120 patients examining a total of 10 unique types of barriers in second-look gynecological surgery. While RCTs on oxidized regenerated cellulose (significant improvement in 6 of 14 trials), polyethylene glycol with/without other agents (4/10), hyaluronic acid and hyaluronate + carboxymethylcellulose (7/10), icodextrin (1/3), dextran (0/3), fibrin-containing agents (1/2), expanded polytetrafluoroethylene (1/1), N,O-carboxymethylchitosan (0/1), and modified starch (1/1) overall showed inconsistent findings, results for expanded polytetrafluoroethylene, hyaluronic acid, and modified starch yielded the greatest improvements regarding adhesion reduction at 75%, 0-67%, and 85%, respectively.

CONCLUSIONS AND RELEVANCE

Best results for adhesion prevention were reported after applying Gore-Tex Surgical Membrane, hyaluronic acid, and 4DryField®. As Gore-Tex Surgical Membrane is nonabsorbable, it is associated with a greater risk of new adhesion formation due to second-look surgery to remove the product. 4DryField® yielded the greatest improvement in adhesion score compared to all other barrier agents (85%). For better comparability, future studies should use standardized scores and put more emphasis on patient-reported outcome measures, such as pain and infertility.

Low Pressure versus Standard Pressure Pneumoperitoneum in Laparoscopic Appendectomy: A Randomized Controlled Trial

BACKGROUND

The creation of pneumoperitoneum using higher pressure is believed to be associated with increased postoperative abdominal pain.

AIM

This study aimed to compare postoperative abdominal pain following low pressure laparoscopic appendectomy and standard pressure laparoscopic appendectomy.

METHODS

This was a prospective, double-blind, randomized controlled trial of 54 patients aged between 18 and 56 years with clinical and/or radiologic diagnosis of acute appendicitis. The patients were randomly allocated to two groups: low pressure laparoscopic appendectomy (n = 26) and standard pressure laparoscopic appendectomy (n = 28). The intra-abdominal pressure was kept in either low pressure (9 mm Hg) or standard pressure (13 mm Hg). Abdominal and shoulder pain scores were assessed using the visual analog scale at 6 hours and 3 days post procedure. Postoperative analgesia requirement, duration of surgery, complications, and hospital stay were recorded.

RESULTS

Both groups match for the demographic parameters. Three patients required conversion from low to standard pressure. There was no difference between the two groups in terms of abdominal pain (P = 0.86) and shoulder pain (P = 0.33), duration of surgery (P = 0.51), complications (P = 0.17), and length of hospital stay (P = 0.83).

CONCLUSION

The use of low pressure pneumoperitoneum did not reduce the incidence of abdominal pain in patients who had laparoscopic appendectomy. Patients with acute appendicitis can be treated with either low or normal pressure pneumoperitoneum depending on the experience of the surgeon.

Underneath Images and Robots, Looking Deeper into the Pneumoperitoneum: A Narrative Review

Laparoscopy offers numerous advantages over open procedures, minimizing trauma, reducing pain, accelerating recovery, and shortening hospital stays. Despite other technical advancements, pneumoperitoneum insufflation has received little attention, barely evolving since its inception. We explore the impact of pneumoperitoneum on patient outcomes and advocate for a minimally invasive approach that prioritizes peritoneal homeostasis. The nonlinear relationship between intra-abdominal pressure (IAP) and intra-abdominal volume (IAV) is discussed, emphasizing IAP titration to balance physiological effects and surgical workspace. Maintaining IAP below 10 mmHg is generally recommended, but factors such as patient positioning and surgical complexity must be considered. The depth of neuromuscular blockade (NMB) is explored as another variable affecting laparoscopic conditions. While deep NMB appears favorable for surgical stillness, achieving a balance between IAP and NMB depth is crucial. Temperature and humidity management during pneumoperitoneum are crucial for patient safety and optical field quality. Despite the debate over the significance of temperature drop, humidification and the warming of insufflated gas offer benefits in peritoneal homeostasis and visual clarity. In conclusion, there is potential for a paradigm shift in pneumoperitoneum management, with dynamic IAP adjustments and careful control of insufflated gas temperature and humidity to preserve peritoneal homeostasis and improve patient outcomes in minimally invasive surgery.

Update on antiadhesion barriers and therapeutics in gynecological surgery

PURPOSE OF REVIEW

Postoperative adhesions remain a clinical challenge to both patients and providers, as they are associated with significant complications and a high economic burden. This article provides a clinical review of currently available antiadhesive agents and promising new therapies that have advanced past animal studies.

RECENT FINDINGS

Several agents have been investigated on their ability to reduce adhesion formation; however, there is no widely acceptable option. The few available interventions are barrier agents and while low-quality evidence suggests that they may be more effective than no treatment, there is no general agreement on their overall efficacy. There is an abundance of research on new solutions; however, their clinical efficacy is yet to be determined.

SUMMARY

Although a wide range of therapeutics have been investigated, majority are halted in animal models with only a select few being studied in humans and ultimately available in the market. Many agents have shown effectiveness in reducing adhesion formation, however, that has not been translated to improvement in clinically relevant outcomes; hence the need for high-quality large randomized trials.

Postsurgical Adhesions: Is There Any Prophylactic Strategy Really Working?

Postoperative adhesions are a frequent complication encountered after surgical procedures, mainly after intraperitoneal interventions. To this day, the pathophysiological mechanism behind the process of adhesions formation is not completely known. There are many strategies proposed as prophylaxis methods, involving surgical techniques, drugs or materials that prevent adhesions and even state of the art technologies such as nanoparticles or gene therapy. The aim of our review is to present these innovative approaches and techniques for postoperative adhesions prevention. After a thorough scientific database query, we selected 84 articles published in the past 15 years that were relevant to our topic. Despite all the recent groundbreaking discoveries, we are at an early stage of understanding the complexity of the adhesion formation mechanism. Further investigations should be made in order to create an ideal product for safe clinical use for prevention.

An Overview of Postoperative Intraabdominal Adhesions and Their Role on Female Infertility: A Narrative Review

Postoperative intraabdominal adhesions can occur after more than 90% of gynecologic surgeries. They not only cause chronic pelvic pain and small bowel obstruction, but are also one of the main reasons for infertility. Adhesions are not only a burden for the affected patients, but are also a burden for the healthcare system, since the treatment of adhesion-associated complications costs a considerable amount of money. The gold standard for the diagnosis of adhesions is by laparoscopy, although other methods, such as transvaginal hydro-laparoscopy, are being discussed as better alternatives. Ideally, adhesions are avoided inherently, by operating carefully and by using microsurgical principles. If this is not possible, gel barriers have been shown to be successful in reducing postoperative adhesions.

Evaluating the concept of gas‑based intraperitoneal hyperthermia beyond 43˚C in the treatment of peritoneal metastasis: A pilot study

While hyperthermic intraperitoneal applications have demonstrated high efficacy in treating peritoneal metastases (PM), these applications are limited to temperatures of 41-43˚C to prevent a harmful increase in core temperature. However, since gaseous substances display low specific heat capacities, gas-based hyperthermia could potentially increase surface temperatures without affecting the body's core temperature. To the best of our knowledge, the present study is the first to explore the in vivo feasibility of gas-based hyperthermia via spatial and time-based distribution. In the present study, a temperature-isolated, abdominal box model was created with fresh peritoneal tissue exposed to continuous high-volume airflow temperatures ranging between 47 and 69˚C. Heat conduction within the peritoneal tissues was measured using temperature microsensors. Temperature build-up at different time points during the procedure was calculated and the safest option to perform gas-based intraperitoneal hyperthermia beyond 43˚C was identified using an in vivo swine model. In subsequent experiments, viability and cytotoxicity of HT-29 colon cancer cells were measured following short-term hyperthermia. The present study demonstrated that the application of gas-based intraperitoneal hyperthermia with temperatures up to 50˚C is possible without increasing the core temperature to harmful levels. Gas-based intraperitoneal hyperthermia can induce a histological reaction on the peritoneal surface, and it can also result in decreased viability and increased cytotoxicity of HT-29 cells. The concept of extreme hyperthermia may be of great clinical importance as it could significantly increase local cytotoxicity in PM without increasing the body's core temperature. Further studies are required to investigate the benefits, as well as the restrictions, of this novel concept.

Effect of Surgical Humidification on Inflammation and Peritoneal Trauma in Colorectal Cancer Surgery: A Randomized Controlled Trial

BACKGROUND

Pre-clinical studies indicate that dry-cold-carbon-dioxide (DC-CO2) insufflation leads to more peritoneal damage, inflammation and hypothermia compared with humidified-warm-CO2 (HW-CO2). Peritoneum and core temperature in patients undergoing colorectal cancer (CRC) surgery were compared.

METHODS

Sixty-six patients were randomized into laparoscopic groups; those insufflated with DC-CO2 or HW-CO2. A separate group of nineteen patients undergoing laparotomy were randomised to conventional surgery or with the insertion of a device delivering HW-CO2. Temperatures were monitored and peritoneal biopsies and bloods were taken at the start of surgery, at 1 and 3 h. Further bloods were taken depending upon hospital length-of-stay (LOS). Peritoneal samples were subjected to scanning electron microscopy to evaluate mesothelial damage.

RESULTS

Laparoscopic cases experienced a temperature drop despite Bair-HuggerTM use. HW-CO2 restored normothermia (≥ 36.5 °C) by 3 h, DC-CO2 did not. LOS was shorter for colon compared with rectal cancer cases and if insufflated with HW-CO2 compared with DC-CO2; 5.0 vs 7.2 days, colon and 11.6 vs 15.4 days rectum, respectively. Unexpectedly, one third of patients had pre-existing damage. Damage increased at 1 and 3 h to a greater extent in the DC-CO2 compared with the HW-CO2 laparoscopic cohort. C-reactive protein levels were higher in open than laparoscopic cases and lower in both matched HW-CO2 groups.

CONCLUSIONS

This prospective RCT is in accord with animal studies while highlighting pre-existing damage in some patients. Peritoneal mesothelium protection, reduced inflammation and restoration of core-body temperature data suggest benefit with the use of HW-CO2 in patients undergoing CRC surgery.

Efficacy of Curcuminoids in managing postoperative pain after total laparoscopic hysterectomy: A randomized controlled, open-label trial

BACKGROUND AND AIMS

Curcuminoids, which are substances extracted from turmeric (Curcuma longa), have anti-inflammatory and analgesic effects and a good safety profile. This study aimed to evaluate the clinical efficacy of curcuminoid extracts on reducing pain among patients who underwent laparoscopic hysterectomy. Experimental procedure: From November 2016 to December 2017, 98 participants were included in this clinical trial, and they were randomly assigned to the experimental and control arms according to blocks of four. The intraoperative findings did not significantly differ between the two groups. The experimental group received one tablet of curcuminoid extract 250 mg four times a day on postoperative days 1-3. Pain was evaluated at 24 and 72 h postoperatively using a 10-point visual analog scale (VAS).

RESULTS AND CONCLUSION

The mean visual analog scale (VAS) scores at 24 h after surgery were 4.9 in the experimental group and 4.3 in the control group. Hence, the results did not significantly differ (p = 0.129). The mean VAS scores at 72 h after surgery were 1.8 in the experimental group and 2.8 in the control group (p = 0.001). The side effects in both groups were similar. Hence, curcuminoids can be an effective supplement for reducing pain after laparoscopic hysterectomy. The conclusion from this study is, that curcuminoids may be an effective supplement to reduce postoperative pain following laparoscopic hysterectomy.

Warm and humidified insufflation gas during gynecologic laparoscopic surgery reduces postoperative pain in predisposed patients-a randomized, controlled multi-arm trial

BACKGROUND

Postoperative pain remains a common problem in gynecologic laparoscopy, especially in head zone-related regions, triggered by intra-abdominal pressure during capnoperitoneum. Humidified and prewarmed insufflation gas may ameliorate pain and be beneficial.

METHODS

This prospective randomized controlled parallel group multi-arm single-center study investigated the effects of temperature and humidity of insufflation gas on postoperative pain during gynecologic laparoscopy with a duration ≥ 60 min. Female participants (18-70 years) were blinded and randomly assigned-computer generated-to either insufflation with dry cold CO₂ with forced air warming blanket ("AIR"), humidified warm gas without forced air warming blanket ("HUMI"), or humidified warm gas with forced air warming blanket ("HUMI +"). We hypothesized that using humidified warm gas resulted in lower pain scores and less analgesic consumption. The primary endpoint postoperative pain was assessed for different pain localizations every 12 h during 7 days after surgery. Secondary endpoints were demand for painkillers and epidural anesthetics, length of stay in recovery room, and hospital stay. (Registration: ClinicalTrials.gov NCT02781194-completed).

RESULTS

150 participants were randomized. Compared to group "AIR" (n = 48), there was significantly less pain in group "HUMI +" (n = 48) in the recovery room (- 1.068; 95% CI - 2.08 to - 0.061), as well as significantly less ibuprofen use at day two (- 0.5871 g ± 0.258; p-value = 0.0471). Other variables did not change significantly. Stratification for presence of endometriosis or non-previous abdominal surgery in patient history revealed significantly less pain in both groups "HUMI" (n = 50) and "HUMI +" versus group "AIR." Related side effects were not noted.

CONCLUSION

In the overall population, the use of warm, humidified insufflation gas did not yield clinically relevant effects; however, in predisposed patients with endometriosis and who could otherwise expect high pain levels, warm and humidified gas may be beneficial.

Effects of modified multimodal analgesia on postoperative pain, sedation, and prognosis of gynecological patients

Patient-controlled intravenous analgesia is one of the most common pain relief methods in  the postoperative period, but its adverse reactions remain high. This study aimed to explore the role of improved combined analgesia methods in pain, sedation, postoperative nausea, and vomiting (PONV) in patients undergoing gynecological surgeries. This study was a prospective, randomized, double-blind controlled study. A study population of 72 patients undergoing gynecological surgery were randomly assigned to either the TAPB + S group or the TAPB + N group. All patients in both groups underwent a transversus abdominis plane block (TAPB) after induction of anesthesia. The TAPB + S group received a continuous intravenous infusion (2 ml/h) of sufentanil (1 μg/kg) plus metoclopramide (30 mg) through 100 ml elastomeric pumps postoperatively. The TAPB + N group received a continuous intravenous infusion (2 ml/h) of nalbuphine hydrochloride (1 mg/kg) plus metoclopramide (30 mg) postoperatively. The main outcome measures were as follows: postoperative pain intensity, Ramsay sedation score (RSS) after surgery, PONV occurrence rate, and rescue analgesics. The RSS of the TAPB + S group was significantly higher than that of the TAPB + N group at 2, 4, and 6 h after the operation. However, the visual analog scale score of the TAPB + S group was much higher than that of the TAPB + N group. No significant differences were found between the two groups in terms of consumption of opioids and other narcotic drugs at 2, 4, 6, 24, and 48 h after the operation. No statistically significant differences were found with respect to PONV and other adverse events in both groups. Taken together, our data indicate that the TAPB + N program can provide better postoperative analgesia and also reduce the use of strong opioids. The more optimized scheme of perioperative analgesia still needs to be researched further.

Effects of Heated Pneumoperitoneum on Inflammation, Oxidative Stress, and Peritoneal Histology in Female Dogs That Underwent Video-Assisted Ovariohysterectomy

Laparoscopic procedures require the creation of pneumoperitoneum. CO₂, which must be cold and dry, is the standard gas used in such surgeries. The type of gas used, its temperature, and moisture may change the peritoneal surface and cause systemic and local oxidative stress. Our objective is to evaluate the influence of pneumoperitoneum heating on the occurrence of histological lesions in the peritoneum, inflammation, plasma oxidative stress, and on the mesothelial surface in patients undergoing video-assisted ovariohysterectomy. Twenty canine females were included and distributed evenly into two groups: heated CO₂ (HG) and unheated CO₂ (UHG). The biomarkers of inflammation and oxidative stress were evaluated before insufflation (T0), at 30 min (T1), and at 60 min (T2) of exposure to CO₂. Biopsies of the peritoneal tissue for histological evaluation were performed at T0 and T2. Regarding plasma parameters, acetylcholinesterase (AChE) showed a greater activity in the HG at T1 (p=0.0268) and T2 (p=0.0423); in turn, butyrylcholinesterase (BChE) showed a greater activity at T2 in the HG (p=0.0175) compared with T0. Catalase activity (CAT) was different between HG times; it was higher at T1 (p=0.0253). There was a decrease in the levels of substances reactive to thiobarbituric acid (TBARS) (p=0.0117) and in glutathione (GSH) (p=0.0114) between T0 and T2 in the UHG. Regarding tissue oxidative stress, the CAT in the HG showed a greater activity at T2 than T1 (p=0.0150). By comparing the groups at each time, there was a difference only at T2 (p=0.0288), being greater in the HG. Regarding the activity of superoxide dismutase (SOD) in the HG, there was a difference between T2 in relation to T0 and T1 (p=0.0181); finally, there was an increase only at T1 (p=0.0287) in the UHG when comparing groups at the same time. There were no differences in the histological parameters evaluated. Our study demonstrates that the heating of CO₂ generates a greater inflammatory response and forms reactive oxygen species (ROS) at the plasma and peritoneal levels.

Pneumoperitoneum induced mesothelial cell changes in a laparoscopic mouse model

BACKGROUND

CO₂ pneumoperitoneum (PP) during laparoscopic surgery, can cause hypoxia and desiccation in the peritoneal mesothelial cell, resulting in a time-dependent retraction and bulging of these cells, an acute inflammatory reaction and enhanced adhesion formation. Since hypoxia is prevented by adding 4% of oxygen (O₂) to the CO₂ PP, the aim of this study was to evaluate the effect of adding 4% O₂ to the CO₂ PP on mesothelial cell morphology.

METHODS

In a standardized laparoscopic mouse model (n=8 mice per group), a control group with a 30- or 60-min PP with humidified CO₂ + 4% of O₂ (groups I and II) was compared to a hypoxic group with 30- or 60-min humidified pure CO₂ (groups III and IV) and a desiccation group with 60-min of dry CO₂ PP (group V). The effect upon the peritoneum morphology was evaluated by scanning electron microscopy (SEM) of abdominal wall peritoneal biopsies. Biopsies, taken immediately (n=4) and 24 hrs (n=4) after surgery, were compared to a group without PP (group VI, n=4). SEM pictures were blindly scored for cell retraction, deletion of microvilli, fibrin deposition, holes in the epithelial layer and visibility of cell borders using a semi-quantitative scoring system.

RESULTS

PP Hypoxia (CO₂ PP) has a deleterious effect upon mesothelial morphology, immediately (holes: p= 0.04) and 24 hrs later (cell retraction: p=0.005; total score: p=0.03) . Desiccation has also a deleterious effect immediately (microvilli p=0.0090; fibrin deposition p=0.05) and 24 hrs after surgery (cell retraction: p=0.0036; holes: p=0.0004; microvilli: p< 0.0001, fibrin deposition: p=0.0225; borders: p=0.0007). This deleterious effect increases with duration of CO₂ PP, affecting cell retraction (p=0.016), holes (p=0.0441), and the total score (p=0.0488). The addition of 4% of O₂ to the CO₂ PP failed to reach statistical significance.

CONCLUSIONS

These data confirm that CO₂ PP and dry gas have a deleterious effect on mesothelial cell morphology. Humidification of the insufflation gas reduces this deleterious effect. The hypothesis of a protective effect of adding O₂ failed to reach significance.

The effects of cold, dry and heated, humidified amniotic insufflation on sheep fetal membranes

INTRODUCTION

Uterine distension with pressurised carbon dioxide (CO₂) (amniotic insufflation) is used clinically to improve visibility during keyhole fetal surgery. However, there are concerns that amniotic insufflation with unconditioned (cold, dry) CO₂ damages the fetal membranes which leads to post-operative preterm prelabour rupture of membranes (iatrogenic PPROM). We assessed whether heating and humidifying the insufflated CO₂ could reduce fetal membrane damage in sheep.

METHODS

Thirteen pregnant ewes at 103-106 days gestation underwent amniotic insufflation with cold, dry (22 °C, 0-5% humidity, n = 6) or heated, humidified (40 °C, 95-100% humidity, n = 7) CO₂ at 15 mmHg for 180 min. Twelve non-insufflated amniotic sacs acted as controls. Fetal membrane sections were collected after insufflation and analysed for molecular and histological markers of cell damage (caspase 3 and high mobility group box 1 [HMGB1]), inflammation (interleukin 1-alpha [IL1-alpha], IL8 and vascular cell adhesion molecule [VCAM]) and collagen weakening (matrix metalloprotease 9 [MMP9]).

RESULTS

Exposure to cold, dry CO₂ increased mRNA levels of caspase 3, HMGB1, IL1-alpha, IL8, VCAM and MMP9 and increased amniotic epithelial caspase 3 and HMGB1 cell counts relative to controls. Exposure to heated, humidified CO₂ also increased IL8 levels relative to controls however, HMGB1, IL1-alpha and VCAM mRNA levels and amniotic epithelial HMGB1 cell counts were significantly lower than the cold, dry group.

DISCUSSION

Amniotic insufflation with cold, dry CO₂ damaged the amniotic epithelium and induced fetal membrane inflammation. Heated, humidified insufflation partially mitigated this damage and inflammation in sheep and may prove an important step in reducing the risk of iatrogenic PPROM following keyhole fetal surgery.

Why Do the Fetal Membranes Rupture Early after Fetoscopy? A Review

Iatrogenic preterm premature rupture of the fetal membranes (iPPROM) remains the Achilles' heel of keyhole fetal surgery (fetoscopy) despite significant efforts in preclinical models to develop new therapies. This limited success is partially due to incomplete understanding why the fetal membranes rupture early after fetoscopy and notable differences in membrane physiology between humans and domestic species. In this review, we summarize aspects of fetoscopy that may contribute to iPPROM, the previous efforts to develop new therapies, and limitations of preclinical models commonly used in fetal membrane research.

The incidence of inadvertent perioperative hypothermia in patients undergoing general anesthesia and an examination of risk factors

BACKGROUND

Unintended perioperative hypothermia, defined as core body temperature less than 36°C, is closely related to many complications such as cardiovascular diseases, peroperative hemorrhagic diathesis and impairment of drug metabolism. Determination of the incidence of perioperative hypothermia and examination of risk factors may help to prevent hypothermia and its complications.

METHODS

We conducted a prospective, observational study of 2015 patients who underwent various operations under general anesthesia, and the risk factors of developing hypothermia were analysed.

RESULTS

The incidence of perioperative hypothermia was 78.6%. The incidence of hypothermia within 2 hours was 56.6%, and after 2 hours, it was 100%. Mean age was 49.36 ± 16.10, and 17.8% were over 65 years old. The mean body mass index (BMI) was 27.96 ± 3.94 kg/m² ; 60.8% of the patients had American Society of Anesthesiologists (ASA) I score, 33.4% had ASA II and 5.8% had ASA III; 35.8% of the patients had co-morbidities. Intravenous and irrigation fluids were unwarmed; 99.9% of the patients were warmed passively, and only 0.1% of patients received active heating intraoperatively. The incidence of hypothermia was higher in overweight (BMI ≥ 25 kg/m² ), elderly (>65 years) patients and those with co-morbidities. High American Society of Anesthesiologists (ASA) scores, grade 3-4 surgery, endoscopic surgery, duration of anesthesia >2 hours, infusion or irrigation >1000 mL significantly increased the incidence of hypothermia.

CONCLUSION

The incidence of perioperative hypothermia found was high. Important risk factors were found as prolonged duration of anesthesia and surgery, advanced age, overweight, high ASA scores, major surgeries, endoscopic operations and unwarmed fluid administration. High incidence may be reduced by raising awareness, considering fossible risk factors and following the recommendations of the guidelines on prevention of perioperative hypothermia.

The effects of CO2 pneumoperitoneum at different temperature and humidity on hemodynamic and respiratory parameters and postoperative pain in gynecological laparoscopic surgery: A prospective randomized controlled study

BACKGROUND

It is recommended to heat and humidity CO₂ in laparoscopic surgery to prevent postoperative pain and hypothermia but information about its effects on hemodynamic and respiratory parameters is limited. We aimed to investigate the effects of standard and heated-humidified CO₂ on hemodynamic and respiratory parameters, body temperature and pain in healthy patients.

METHODS

One hundred patients who underwent total laparoscopic hysterectomy for benign pathology were divided into two groups: Group CD (cold-dry) patients were administered standard CO₂, while Group HH (heated-humidified) patients were administered 95% humidified insufflation at 37 °C. Hemodynamic and respiratory parameters, body temperature, pain score and blood count parameters were recorded.

RESULTS

A total of 96 patients were included in the study, taken from the 100 patients. Group HH (n:47) had only higher systolic blood pressure at 75, mean blood pressure at 50 and 55 and a lower heart rate between 15 and 45 min (p:0.049, 0.037, 0.013 respectively). Pain score, morphine consumption, end-tidal CO₂ and arterial blood gas values were not different between the groups, with only body temperature from 40 min and minimum value being significantly higher (at a difference of 0.86-1.04 °C) in Group HH. Postoperative leukocyte, neutrophil and NLR (neutrophil-leukocyte ratio) were found to be higher in this group (p < 0.05).

CONCLUSION

It has been found that both standard and heated-humidified CO₂do not constitute a problem in terms of hemodynamic and respiratory parameters in healthy patients. The heated-humidified CO₂group had only a higher core body temperature and inflammatory response.

TRIAL REGISTRATION

NCT04508387.

Efficacy and safety of Seprafilm for preventing intestinal obstruction after gastrointestinal neoplasms surgery: a systematic review and meta-analysis

OBJECTIVE

It was controversial that hyaluronate-carboxy-methylcellulose-based membrane (Seprafilm) could prevent intestinal obstruction after gastrointestinal neoplasms operation. This study aimed to evaluate the efficacy and safety of Seprafilm in preventing postoperative intestinal obstruction of gastrointestinal neoplasms patients.

METHODS

A systematic research of multiple databases was performed to identify relevant studies, and the studies satisfying the inclusion criteria were included. Risk ratio (RR), weighted mean difference (WMD), and 95% confidence intervals were calculated using RevMan 5.3.

RESULTS

2937 patients from 10 studies who were enrolled in this meta-analysis were divided into the Seprafilm group (n = 1334) and the control group (n = 1603). The Seprafilm group had lower incidence of intestinal obstruction (RR, 0.52; 95% CI, 0.38-0.70; p < .0001), reoperation rates due to intestinal obstruction (RR, 0.48; 95% CI, 0.28 - 0.80; p = .005), incidence of overall complications (RR, 0.77; 95% CI, 0.61-0.97; p = .03) and higher serum creatinine on postoperative day 5 (WMD, 0.15; 95% CI, 0.05-0.25; p = .003). There were no differences regarding time to intestinal obstruction after operation, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, white blood cell count results on day 5 and 7, serum creatinine on day 7, hospital stay, and incidence of intra-abdominal infection, wound infection, anastomotic leakage between the 2 groups.

CONCLUSIONS

This meta-analysis provided valuable evidence-based support for the efficacy and safety of Seprafilm in preventing postoperative intestinal obstruction of gastrointestinal neoplasms patients. However, more multicenter randomized controlled trials from different countries are needed.

Modes of carbon dioxide delivery during laparoscopy generate distinct differences in peritoneal damage and hypoxia in a porcine model

BACKGROUND

Insufflation with CO₂ can employ continuous flow, recirculated gas and/or additional warming and humidification. The ability to compare these modes of delivery depends upon the assays employed and opportunities to minimize subject variation. The use of pigs to train colorectal surgeons provided an opportunity to compare three modes of CO₂ delivery under controlled circumstances.

METHODS

Sixteen pigs were subjected to rectal resection, insufflated with dry-cold CO₂ (DC-CO₂) (n = 5), recirculated CO₂ by an AirSeal device (n = 5) and humidification and warming (HW-CO2) by a HumiGard device (n = 6). Peritoneal biopsies were harvested from the same region of the peritoneum for fixation for immunohistochemistry for hypoxia-inducible factor 1 alpha (HIF-1α) and scanning electron microscopy (SEM) to evaluate hypoxia induction or tissue/cellular damage, respectively.

RESULTS

DC-CO₂ insufflation by both modes leads to significant damage to mesothelial cells as measured by cellular bulging and retraction as well as microvillus shortening compared with HW-CO₂ at 1 to 1.5 h. DC-CO₂ also leads to a rapid and significant induction of HIF-1α compared with HW-CO₂.

CONCLUSIONS

DC-CO₂ insufflation induces substantive cellular damage and hypoxia responses within the first hour of application. The use of HW-CO₂ insufflation ameliorates these processes for the first one to one and half hours in a large mammal used to replicate surgery in humans.

Laparoscopic surgery for T4 colon cancer: a risk factor for peritoneal recurrences?

BACKGROUND

Although some preclinical studies have inferred that laparoscopic surgery for advanced cancer may increase the risk of peritoneal metastasis, this potential hazard has not been fully evaluated in the clinical setting. This study aimed to clarify whether laparoscopic surgery is associated with an increased risk of postoperative peritoneal recurrence after resection of T4 colon cancer.

METHODS

This study included 272 patients who underwent curative resection for pathological T4a colon cancer without distant metastases at the University of Tokyo Hospital between 1997 and 2017. Multivariable Fine-Gray analysis was performed to evaluate whether the use of laparoscopy was an independent risk factor for postoperative peritoneal recurrence. Thereafter, oncological outcomes (overall and relapse-free survival, and organ-specific recurrence) were compared between laparoscopic colectomy and open colectomy using propensity score matching.

RESULTS

Multivariable analysis found that laparoscopic surgery was a significant risk factor for postoperative peritoneal recurrence (hazard ratio: 1.89; 95% confidence interval: 1.01-3.65; P = .046). Comparison after propensity score matching revealed that the incidence of peritoneal recurrence was significantly higher after laparoscopic colectomy than after open colectomy (5-year cumulative incidence: 28.1% vs 12.1%; P = .003).

CONCLUSION

This study suggested that laparoscopic surgery may be related to an increased risk of peritoneal recurrence in patients with pathological T4a colon cancer. Clinicians should be fully aware of this potential risk and seek an optimal treatment plan for the prevention and early detection of peritoneal metastasis.

Randomized clinical trial of the effect of intraoperative humidified carbon dioxide insufflation in open laparotomy for colorectal resection

BACKGROUND

Animal studies have shown that peritoneal injury can be minimized by insufflating the abdominal cavity with warm humidified carbon dioxide gas.

METHODS

A single-blind RCT was performed at a tertiary colorectal unit. Inclusion criteria were patient aged 18 years and over undergoing open elective surgery. The intervention group received warmed (37°C), humidified (98 per cent relative humidity) carbon dioxide (WHCO2  group). Multiple markers of peritoneal inflammation and oxidative damage were used to compare groups, including cytokines and chemokines, apoptosis, the 3-chlorotyrosine/native tyrosine ratio, and light microscopy on peritoneal biopsies at the start (T0 ) and end (Tend ) of the operation. Postoperative clinical outcomes were compared between the groups.

RESULTS

Of 40 patients enrolled, 20 in the WHCO2 group and 19 in the control group were available for analysis. A significant log(Tend /T0 ) difference between control and WHCO2 groups was documented for interleukin (IL) 2 (5·3 versus 2·8 respectively; P = 0·028) and IL-4 (3·5 versus 2·0; P = 0·041), whereas apoptosis assays documented no significant change in caspase activity, and similar apoptosis rates were documented along the peritoneal edge in both groups. The 3-chlorotyrosine/tyrosine ratio had increased at Tend by 1·1-fold in the WHCO2 group and by 3·1-fold in the control group. Under light microscopy, peritoneum was visible in 11 of 19 samples from the control group and in 19 of 20 samples from the WHCO2 group (P = 0·006). The only difference in clinical outcomes between intervention and control groups was the number of days to passage of flatus (2·5 versus 5·0 days respectively; P = 0·008).

CONCLUSION

The use of warmed, humidified carbon dioxide appears to reduce some markers related to peritoneal oxidative damage during laparotomy. No difference was observed in clinical outcomes, but the study was underpowered for analysis of surgical results. Registration number: NCT02975947 ( www.ClinicalTrials.gov/).

Intraperitoneal aerosolized drug delivery: Technology, recent developments, and future outlook

Current therapies for patients with peritoneal metastases (PM) are only moderately effective. Recently, a novel locoregional treatment method for PM was introduced, consisting of a combination of laparoscopy with intraperitoneal (IP) delivery of anticancer agents as an aerosol. This 'pressurized intraperitoneal aerosol chemotherapy' (PIPAC) may enhance tissue drug penetration by the elevated IP pressure during CO₂ capnoperitoneum. Also, repeated PIPAC cycles allow to accurately stage peritoneal disease and verify histological response to treatment. This review provides an overview of the rationale, indications, and currently used technology for therapeutic IP nebulization, and discusses the basic mechanisms governing aerosol particle transport and peritoneal deposition. We discuss early clinical results in patients with advanced, irresectable PM and highlight the potential of electrostatic aerosol precipitation. Finally, we discuss promising novel approaches, including nebulization of nanoparticles and prolonged release formulations.

Hypoxia-Mesenchymal Stem Cells Inhibit Intra-Peritoneal Adhesions Formation by Upregulation of the IL-10 Expression

BACKGROUND

Intra-peritoneal adhesions (IPAs) common occurre in post abdominal surgical. Athough many methods have been developed for controlling IPAs, including mesenchymal stem cells (MSCs) application, however, there is none completely preventing in due to the mesothelial structure may promote the prolonged inflammations leading. Nevertheless hypoxia-MSCs (H-MSCs) have more potent in controlling the inflammation than normoxia-MSCs (N-MSCs) by releasing several anti-inflamation particularly IL-10, however the H-MSCs application to inhibit IPAs remain unclear.

AIM

The aim of this study was to investigate the effectiveness of H-MSCs in preventing the AIPs event by releasing IL-10 on the ileum abrasion sutured omental patch as the animal model of peritoneal adhesion.

METHODS

Using 24 IPAs animal model were randomly divided into 4 groups: Sham (Sh), Control (C), H-MSCs at high dose (T1) and H-MSCs at low dose (T2). H-MSCs were incubated under hypoxic conditions (5% O₂), 37°C and 5% CO₂ for 24 hours. The expression level of IL-10 was performed using RT-PCR analysis. The macroscopic appearance of IPAs was evaluated using Nair's scale base on the absence/presence of adhesion, whereas the microscopic by Zuhlke's scale at Hematoxylin and eosin (H&E) staining.

RESULTS

This study showed a significanly increase in IL-10 expression (p < 0.05) at all T groups. In line with this, we also found a significant difference in IPAs between T groups and Control as well as a Sham (p < 0.05) either in the macroscopic or microscopic analysis.

CONCLUSION

H-MSCs has a robust ability in inhibiting severe IPAs characterized by the decreased of adhesion formation and the enhanced expression of IL-10.

The impact of warmed and humidified CO2 insufflation during robotic radical prostatectomy: Results of a randomized controlled trial

Background:

Cool and dry gas insufflation during laparoscopy induces hypothermia and cytokine increase, with significant perioperative morbidity. Our aim was to assess if warmed and humidified CO2 insufflation with HumiGard™ device can achieve significant benefits over standard insufflation in terms of risk of hypothermia, cytokine response, blood gases, and intra- and postoperative parameters, in the setting of robot-assisted radical prostatectomy (RARP).

Methods:

This was a prospective, randomized controlled clinical trial. Sixty-four patients with prostate cancer undergoing RARP were randomized to receive warmed and humidified CO2 insufflation with HumiGard device, plus hot air warming blanket (treatment group, H + WB), or standard CO2 insufflation, plus hot air warming blanket (control group, WB). Body core temperature (BCT), plasma levels of IL-6 and TNF-α, pain scores, and intraoperative parameters were recorded. The data were analyzed according to the Bayesian paradigm.

Results:

Intraoperative BCT increased in both groups during surgery, with a statistically significant difference favoring group H + WB, ending at 0.2°C higher on average than group WB. No difference across groups was shown for cytokine levels. Blood gas parameters were not affected by warmed CO2 insufflation. No statistical differences were noted for pain scores and the other intra- and postoperative parameters.

Conclusions:

During RARP, warm and humidified CO2 insufflation with the HumiGard device was more effective than the standard CO2 insufflation in maintaining the patient’s heat homeostasis, even if the difference was minimal. No imbalances were detected on blood gas analyses. No benefit could be shown in terms of cytokine levels and pain scores.

Physiological effects of partial amniotic carbon dioxide insufflation with cold, dry vs heated, humidified gas in a sheep model

OBJECTIVE

Partial amniotic carbon dioxide (CO₂ ) insufflation (PACI) is used to improve visualization and facilitate complex fetoscopic surgery. However, there are concerns about fetal hypercapnic acidosis and postoperative fetal membrane inflammation. We assessed whether using heated and humidified, rather than cold and dry, CO₂ might reduce the impact of PACI on the fetus and fetal membranes in sheep.

METHODS

Twelve fetal lambs of 105 days' gestational age (term = 145 days) were exteriorized partially, via a midline laparotomy and hysterotomy, and arterial catheters and flow probes were inserted surgically. The 10 surviving fetuses were returned to the uterus, which was then closed and insufflated with cold, dry (22 °C at 0-5% humidity, n = 5) or heated, humidified (40 °C at 100% humidity, n = 5) CO₂ at 15 mmHg for 180 min. Fetal membranes were collected immediately after insufflation for histological analysis. Physiological data and membrane leukocyte counts, suggestive of membrane inflammation, were compared between the two groups.

RESULTS

After 180 min of insufflation, fetal survival was 0% in the group which underwent PACI with cold, dry CO₂ , and 60% (n = 3) in the group which received heated, humidified gas. While all insufflated fetuses became progressively hypercapnic (PaCO₂  > 68 mmHg), this was considerably less pronounced in those in which heated, humidified gas was used: after 120 min of insufflation, compared with those receiving cold, dry gas (n = 3), fetuses undergoing heated, humidified PACI (n = 5) had lower arterial partial pressure of CO₂ (mean ± standard error of the mean, 82.7 ± 9.1 mmHg for heated, humidified CO₂ vs 170.5 ± 28.5 for cold, dry CO₂ during PACI, P < 0.01), lower lactate levels (1.4 ± 0.4 vs 8.5 ± 0.9 mmol/L, P < 0.01) and higher pH (pH, 7.10 ± 0.04 vs 6.75 ± 0.04, P < 0.01). There was also a non-significant trend for fetal carotid artery pressure to be higher following PACI with heated, humidified compared with cold, dry CO₂ (30.5 ± 1.3 vs 8.7 ± 5.5 mmHg, P = 0.22). Additionally, the median (interquartile range) number of leukocytes in the chorion was significantly lower in the group undergoing PACI with heated, humidified CO₂ compared with the group receiving cold, dry CO₂ (0.7 × 10^-5 (0.5 × 10^-5 ) vs 3.2 × 10^-5 (1.8 × 10^-5 ) cells per square micron, P = 0.02).

CONCLUSIONS

PACI with cold, dry CO₂ causes hypercapnia, acidosis, hypotension and fetal membrane inflammation in fetal sheep, raising potential concerns for its use in humans. It seems that using heated, humidified CO₂ for insufflation partially mitigates these effects and this may be a suitable alternative for reducing the risk of fetal acid-base disturbances during, and fetal membrane inflammation following, complex fetoscopic surgery. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Partial amniotic carbon dioxide insufflation for fetal surgery

Partial amniotic carbon dioxide insufflation (PACI) involves insufflating the amniotic sac with carbon dioxide (CO₂ ) and, in some cases, draining some of the amniotic fluid. The creation of a gaseous intra-amniotic compartment improves visualization, even in the presence of limited bleeding, and creates the work space required for complex fetoscopic procedures. Clinically, PACI is mostly used to perform fetoscopic myelomeningocele (MMC) repair, enabling a minimally invasive alternative to open fetal surgery. However, evidence of the fetal safety of PACI is limited. Previous animal experiments in sheep demonstrate that PACI induces fetal hypercapnia and acidosis with largely unknown short and longer term implications. In this review, we examine the literature for the physiological effects of intrauterine insufflation pressure, duration, humidity, and the role of maternal hyperventilation on fetal physiology and well-being.

The sticky business of adhesion prevention in minimally invasive gynecologic surgery

PURPOSE OF REVIEW

The negative impact of postoperative adhesions has long been recognized, but available options for prevention remain limited. Minimally invasive surgery is associated with decreased adhesion formation due to meticulous dissection with gentile tissue handling, improved hemostasis, and limiting exposure to reactive foreign material; however, there is conflicting evidence on the clinical significance of adhesion-related disease when compared to open surgery. Laparoscopic surgery does not guarantee the prevention of adhesions because longer operative times and high insufflation pressure can promote adhesion formation. Adhesion barriers have been available since the 1980s, but uptake among surgeons remains low and there is no clear evidence that they reduce clinically significant outcomes such as chronic pain or infertility. In this article, we review the ongoing magnitude of adhesion-related complications in gynecologic surgery, currently available interventions and new research toward more effective adhesion prevention.

RECENT FINDINGS

Recent literature provides updated epidemiologic data and estimates of healthcare costs associated with adhesion-related complications. There have been important advances in our understanding of normal peritoneal healing and the pathophysiology of adhesions. Adhesion barriers continue to be tested for safety and effectiveness and new agents have shown promise in clinical studies. Finally, there are many experimental studies of new materials and pharmacologic and biologic prevention agents.

SUMMARY

There is great interest in new adhesion prevention technologies, but new agents are unlikely to be available for clinical use for many years. High-quality effectiveness and outcomes-related research is still needed.

Experimental study of delivery of humidified-warm carbon dioxide during open abdominal surgery

Background

The aim of this study was to monitor the effect of humidified‐warm carbon dioxide (HWCO₂) delivered into the open abdomen of mice, simulating laparotomy.

Methods

Mice were anaesthetized, ventilated and subjected to an abdominal incision followed by wound retraction. In the experimental group, a diffuser device was used to deliver HWCO₂; the control group was exposed to passive air flow. In each group of mice, surgical damage was produced on one side of the peritoneal wall. Vital signs and core temperature were monitored throughout the 1‐h procedure. The peritoneum was closed and mice were allowed to recover for 24 h or 10 days. Tumour cells were delivered into half of the mice in each cohort. Tissue was then examined using scanning electron microscopy and immunohistochemistry.

Results

Passive air flow generated ultrastructural damage including mesothelial cell bulging/retraction and loss of microvilli, as assessed at 24 h. Evidence of surgical damage was still measurable on day 10. HWCO₂ maintained normothermia, whereas open surgery alone led to hypothermia. The degree of tissue damage was significantly reduced by HWCO₂ compared with that in controls. Peritoneal expression of hypoxia inducible factor 1α and vascular endothelial growth factor A was lowered by HWCO₂. These effects were also evident at the surgical damage sites, where protection from tissue trauma extended to 10 days. HWCO₂ did not reduce tumorigenesis in surgically damaged sites compared with passive air flow.

Conclusion

HWCO₂ diffusion into the abdomen in the context of open surgery afforded tissue protection and accelerated tissue repair in mice, while preserving normothermia.

Managing Postoperative Pain After Minimally Invasive Gynecologic Surgery in the Era of the Opioid Epidemic

In this review, we examine the evidence behind nonopioid medication alternatives, peripheral nerve blocks, surgical techniques, and postoperative recovery protocols that can help minimize and effectively treat postoperative pain after minimally invasive gynecologic surgery (MIGS). Because of the depth and heterogeneity of the data, a narrative review was performed of reported interventions. A comprehensive review was performed of PubMed, Embase, and the Cochrane Database with a focus on randomized controlled trials. In the absence of literature specific to benign gynecology, similar specialty or procedural data were reviewed. A variety of nonopioid medications, surgical techniques, and postoperative recovery protocols have shown significant improvements in postoperative pain after gynecologic surgery. Nonopioid medication options that are beneficial include acetaminophen, nonsteroidal anti-inflammatories, and antiepileptics. Incision infiltration with local anesthesia also significantly reduces pain. Surgically, minimally invasive approaches, reducing the laparoscopic trocar size to <10 mm, and evacuating the pneumoperitoneum at the end of the case all have significant benefits. Lastly, enhanced recovery pathways show promise in reducing pain after MIGS. By using a multimodal approach, minimally invasive gynecologic surgeons can help to minimize and manage postoperative pain with less reliance on opioid pain medications.

Prospective, randomized comparison of the use of FloShield Air System® versus the reference technique (water + povidone-iodine solution) during gynecologic endoscopic surgery to evaluate the operative lens vision quality

BACKGROUND

The FloShield Air System^® is a new device for laparoscopic surgery that utilizes a continuous dry CO₂ gas flow over the scope to defog the lens and protect it from condensation, debris and smoke. We set out to compare the performance and efficiency of the device in terms of operative lens vision quality (OLVQ) with the reference technique (water + povidone-iodine (PVI) solution) during gynecologic laparoscopic surgery.

MATERIALS AND METHODS

We conducted a single-center randomized prospective study between March and June 2016 (Trials Database Registration NCT02702531) including 53 patients undergoing gynecologic laparoscopic surgery with water + PVI solution and 51 patients who underwent surgical procedures with the FloShield Air System. The primary outcome measure was the number of laparoscope removals during surgery. Secondary outcome measures were the time to clean, assessment of the quality of vision, the correlation between the laparoscopic surgical complexity and outcomes, and cost effectiveness.

RESULTS

Overall, the mean patient age was 43.2 years (range 22-86) and body mass index 24.8 (range 16.8-42.7). The mean number of endoscope removals during surgery was 7.0 (range 0-37) in the water + PVI solution arm and 2.8 (range 0-12) in the FloShield Air System^® arm. The number of removals was significantly lower in the FloShield arm (p < 0.001). No difference in time to clean, quality of vision, level of laparoscopic procedure complexity, or cost was observed between the groups.

CONSLUSIONS

The FloShield Air System^® resulted in fewer laparoscopic lens removals than the water + PVI solution solution, but that there was no difference in quality of vision, cleaning time or cost, especially for the more complex surgery.

Changes in the coelomic microclimate during carbon dioxide laparoscopy: morphological and functional implications

In this article the adverse effects of laparoscopic CO2 pneumoperitoneum and coelomic climate change, and their potential prevention by warmed, humidified carbon dioxide insufflation are reviewed. The use of pressurized cold, dry carbon dioxide (C02) pneumoperitoneum causes a number of local effects on the peritoneal mesothelium, as well as systemic effects. These can be observed at a macroscopic, microscopic, cellular and metabolic level. Local effects include evaporative cooling, oxidative stress, desiccation of mesothelium, disruption of mesothelial cell junctions and glycocalyx, diminished scavenging of reactive oxygen species, decreased peritoneal blood flow, peritoneal acidosis, peritoneal hypoxia or necrosis, exposure of the basal lamina and extracellular matrix, lymphocyte infiltration, and generation of peritoneal cytokines such as IL-1, IL-6, IL-8 and TNFα. Such damage is increased by high CO2 insufflation pressures and gas velocities and prolonged laparoscopic procedures. The resulting disruption of the glycocalyx, mesothelial cell barrier and exposure of the extracellular matrix creates a cascade of immunological and pro-inflammatory events and favours tumour cell implantation. Systemic effects include cardiopulmonary and respiratory changes, hypothermia and acidosis. Such coelomic climate change can be prevented by the use of lower insufflation pressures and preconditioned warm humidified CO2. By achieving a more physiological temperature, pressure and humidity, the coelomic microenvironment can be better preserved during pneumoperitoneum. This has the potential clinical benefits of maintaining isothermia and perfusion, reducing postoperative pain, preventing adhesions and inhibiting cancer cell implantation in laparoscopic surgery.

Changes in the coelomic microclimate during carbon dioxide laparoscopy: morphological and functional implications

In this article the adverse effects of laparoscopic CO2 pneumoperitoneum and coelomic climate change, and their potential prevention by warmed, humidified carbon dioxide insufflation are reviewed. The use of pressurized cold, dry carbon dioxide (C02) pneumoperitoneum causes a number of local effects on the peritoneal mesothelium, as well as systemic effects. These can be observed at a macroscopic, microscopic, cellular and metabolic level. Local effects include evaporative cooling, oxidative stress, desiccation of mesothelium, disruption of mesothelial cell junctions and glycocalyx, diminished scavenging of reactive oxygen species, decreased peritoneal blood flow, peritoneal acidosis, peritoneal hypoxia or necrosis, exposure of the basal lamina and extracellular matrix, lymphocyte infiltration, and generation of peritoneal cytokines such as IL-1, IL-6, IL-8 and TNFα. Such damage is increased by high CO2 insufflation pressures and gas velocities and prolonged laparoscopic procedures. The resulting disruption of the glycocalyx, mesothelial cell barrier and exposure of the extracellular matrix creates a cascade of immunological and pro-inflammatory events and favours tumour cell implantation. Systemic effects include cardiopulmonary and respiratory changes, hypothermia and acidosis. Such coelomic climate change can be prevented by the use of lower insufflation pressures and preconditioned warm humidified CO2. By achieving a more physiological temperature, pressure and humidity, the coelomic microenvironment can be better preserved during pneumoperitoneum. This has the potential clinical benefits of maintaining isothermia and perfusion, reducing postoperative pain, preventing adhesions and inhibiting cancer cell implantation in laparoscopic surgery.

Cost-utility analysis of the insufflation of warmed humidified carbon dioxide during open and laparoscopic colorectal surgery

BACKGROUND

An evaluation was conducted to estimate the cost-effectiveness of insufflation of warmed humidified CO₂ during open and laparoscopic colorectal surgery compared with usual care from a UK NHS perspective.

METHODS

Decision analytic models were developed for open and laparoscopic surgery. Incremental costs per quality-adjusted life year (QALY) were estimated. The open surgery model used data on the incidence of intra-operative hypothermia and applied risks of complications for hypothermia and normothermia. The laparoscopic surgery model utilised data describing complications directly. Sensitivity analyses were conducted.

RESULTS

Compared with usual care, insufflation of warmed humidified CO₂ dominated. For open surgery, savings of £20 and incremental QALYs of 0.013 were estimated per patient. For laparoscopic surgery, savings of £345 and incremental QALYs of 0.001 per patient were estimated. Results were robust to most sensitivity analyses.

CONCLUSIONS

Considering the current evidence base, the intervention is likely to be cost-effective compared with usual care in patients undergoing colorectal surgery.

The Onset of Intra-Abdominal Adhesions During Closed-Abdomen Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

Hyperthermic intraperitoneal chemotherapy (HIPEC) is delivered after cytoreductive surgery (CRS) in selected patients with peritoneal carcinomatosis. The closed-abdomen technique, preferred by many centers, prevents heat loss and drug spillage, but does not warrant homogeneous distribution of the perfusion fluid (PF). The hypothesized formation of intra-abdominal adhesions during the closed-abdomen perfusion period has never been described.

MATERIALS AND METHODS

From March 2014 to April 2016, 10 consecutive patients with peritoneal carcinomatosis, selected for CRS, underwent the Laparoscopy-Enhanced HIPEC technique to explore the abdominal cavity during the perfusion. The aim of the study was to investigate the incidence and the extent of intra-abdominal adhesions that are formed after CRS during the perfusion period of closed-abdomen HIPEC.

RESULTS

During the perfusion, adhesions developed in 70% of the patients. Adhesions developed mainly in the period between the closure of the abdomen and the subsequent filling of the abdomen with the PF. After their first division, during the following perfusion period, adhesions between the bowel and the abdominal wall reformed in 3 patients (30%).

CONCLUSIONS

Intra-abdominal adhesions are frequently formed during closed-abdomen HIPEC and can hamper the adequate circulation of the PF. The Laparoscopy-Enhanced technique enables the early detection and the division of any intra-abdominal adhesions.

Warmed and humidified carbon dioxide for abdominal laparoscopic surgery: meta-analysis of the current literature

BACKGROUND

The creation of a pneumoperitoneum for laparoscopic surgery is performed by the insufflation of carbon dioxide (CO₂). The insufflated CO₂ is generally at room temperature (20-25 °C) and dry (0-5 % relative humidity). However, these physical characteristics could lead to alterations of the peritoneal cavity, leading to operative and postoperative complications. Warming and humidifying the insufflated gas has been proposed to reduce the iatrogenic effects of laparoscopic surgery, such as pain, hypothermia and peritoneal alterations. Two medical devices are currently available for laparoscopic surgery with warm and humidified CO₂.

METHODS

Clinical studies were identified by searching PubMed with keywords relating to humidified and warmed CO₂ for laparoscopic procedures. Analysis of the literature focused on postoperative pain, analgesic consumption, duration of hospital stay and convalescence, surgical techniques and hypothermia.

RESULTS

Bibliographic analyses reported 114 publications from 1977 to 2015, with only 17 publications of clinical interest. The main disciplines focused on were gynaecological and digestive surgery ). Analysis of the studies selected reported only a small beneficial effect of warmed and humidified laparoscopy compared to standard laparoscopy on immediate postoperative pain and per procedure hypothermia. No difference was observed for later postoperative shoulder pain, morphine equivalent daily doses, postoperative body core temperature, recovery room and hospital length of stay, lens fogging and procedure duration.

CONCLUSIONS

Only few beneficial effects on immediate postoperative pain and core temperature have been identified in this meta-analysis. Although more studies are probably needed to close the debate on the real impact of warmed and humidified CO₂ for laparoscopic procedures.