Intraperitoneal insufflation of carbon dioxide rescues intestinal damage in an experimental murine model of colitis.

OBJECTIVES: Necrotizing enterocolitis (NEC) is a severe neonatal surgical condition, associated with a prolonged pro-inflammatory state, leading to high mortality and morbidity rates. Carbon dioxide (CO2 ) insufflation during laparoscopy may have an anti-inflammatory effect. We aimed to evaluate the effects of CO2 -insufflation on experimental colitis. METHODS: Acute colitis was induced in 6-week-old Balb/c mice by the administration of 2%-dextran sulfate-sodium (DSS) during 7 days (n = 45). On Day 4, two groups received intraperitoneal insufflation (duration: 30 mn, pressure: 5 mmHg) of CO2 ("DSS+CO2 ") or air ("DSS+air"). A group received no insufflation ("DSS"). Groups were compared for clinical severity using the disease activity index (DAI-body weight loss, stool consistency, and bleeding), histological severity (histopathological activity index, colon length, and ulcerations), colonic mucosecretion, and inflammation. RESULTS: DAI was significantly decreased in DSS+CO2 group, compared to DSS (p < 0.0001) or DSS+air (p < 0.0001) groups. Colon length was increased in DSS+CO2 treated mice compared to DSS (p = 0.0002). The histopathological activity index was lower in DSS+CO2 (vs. DSS, p = 0.0059/vs. DSS+air, p = 0.0389), with decreased ulcerations (3.77 vs. 10.7, p = 0.0306), and persistent mucosecretion with increased mucin-secreting cells. CONCLUSIONS: CO2 -insufflation attenuates DSS-induced colitis and improves both clinical and histological scores. Laparoscopy with CO2 insufflation represents a therapeutic anti-inflammatory strategy for NEC.

A new reliable acoustic respiratory monitoring technology during upper gastrointestinal tract therapeutic endoscopy with CO2 insufflation.

Previous studies documented the effectiveness and benefits of capnography monitoring during propofol-based sedation for colonoscopy to reduce the incidence of hypoxemia. However, the performance of capnography during longer duration endoscopic therapy of upper gastrointestinal tract cancers under CO2 insufflation it is not well known. In this study, we compare a new device with acoustic monitoring technology to standard capnography monitoring. We retrospectively analyzed 49 patients who underwent endoscopic resection of early upper gastrointestinal tract cancer between December 2013 and October 2014. All 49 patients were monitored using both acoustic monitoring technology and standard capnography. We investigated the duration of the periods with unmeasurable respiratory rate during the overall procedure. When comparing standard capnography monitoring to the new acoustic monitoring technology, the ratio of the unmeasurable time was significantly lower in RRa (36.9% vs. 21.6%, p < 0.01). The ratio of unmeasurable respiratory rate by capnography was strongly correlated to the ratio of unmeasurable PETCO2 level by capnography (R2 = 0.847). There were no severe events or adverse events (grade 2 or more) during all 49 procedures. The acoustic monitoring technology provides a more reliable respiratory monitoring when compared to standard capnography during endoscopic resection of upper gastrointestinal tract cancers under CO2 insufflation, even if the procedures were prolonged and complex.

Effects of Warmed and Humidified CO2 Surgical Site Insufflation in a Novel Experimental Model of Magnetic Compression Colonic Anastomosis.

Background. Pneumoperitoneum insufflation with warmed and humidified carbon dioxide (WH-CO2) can prevent heat loss and increase tissue oxygenation. We evaluated the impact of localized WH-CO2 insufflation on the anastomotic healing process. Methods. Sixty male Wistar rats were randomized: Group 1 (control, n = 12), Group 2 (cold and dry CO2, CD-CO2, n = 24), and Group 3 (WH-CO2, n = 24). A magnetic compression side-to-side colonic anastomosis was performed under 60-minute local abdominal CO2 flow insufflation. Animal temperature was recorded. IL-1, IL-6, and CRP levels were assessed before and after insufflation and on postoperative day (POD) 7 and POD 10. Endoscopic follow-up was performed on POD 7 and POD 10. A burst pressure (BP) test of the specimen was performed on POD 10, and histopathological analysis was then performed. Metabolomics of the anastomotic site was determined. Results. Seven rats (5 CD-CO2 group, 1 WH-CO2 group, and 1 control group) died during the survival period. Necropsies revealed intestinal occlusions (n = 2). One additional rat from the CD-CO2 group was sacrificed on POD 7 due to intestinal perforation. The postoperative course was uneventful in the remaining cases. There was no difference in BP among the groups. Thermal monitoring confirmed that WH-CO2 insufflation was effective to reduce heat loss. IL-1 levels were statistically and significantly lower on POD 10 in the WH-CO2 group than the CD-CO2 group but not lower than the control group. CRP levels, histopathology, and metabolomics did not show any difference between the 3 groups. Conclusions. WH-CO2 was effective to preserve core temperature. However, it did not improve anastomotic healing.

The Usefulness of Endoscopic Harvesting of the Latissimus Dorsi Flap for Breast Reconstruction Using a Single-Port and CO2 Gas Insufflation Technique.

BACKGROUND: In the recent trend toward less aggressive approaches to breast reconstruction, minimally invasive harvesting of the latissimus dorsi (LD) flaps has long been a desirable goal. Endoscopically-assisted LD flap harvesting was reported as a method for minimizing scar formation and reducing donor-site morbidity. This study investigates the surgical outcomes of endoscopically-assisted immediate breast reconstruction with LD muscle flaps. MATERIALS AND METHODS: This prospective study included 21 patients who underwent endoscopically-assisted breast reconstruction with LD muscle flap and 20 patients who underwent breast reconstruction with conventional harvesting LD musculocutaneous flap. In patients with nonexcised skin or possible primary closure, the reconstruction was performed with endoscopically-assisted LD muscle flaps using the single-port and CO2 gas insufflation technique. The patients were classified into groups according to the location of the defect and mastectomy type. Moreover, patient satisfaction was investigated 6 months after surgery. RESULTS: In patients who underwent endoscopically-assisted breast reconstruction with LD muscle flaps, the scar of the donor-site was vertical, and the size was 4 cm to be obscured when lowering the arms. In comparison with patients who underwent breast reconstruction with conventional LD flaps, those who underwent endoscopically-assisted breast reconstruction with LD muscle flaps showed shorter hospital stay and no difference in patient satisfaction. CONCLUSION: Endoscopically-assisted breast reconstruction with LD flaps showed no difference in patient satisfaction with good esthetic results compared with conventional LD flaps. The endoscopic LD muscle flap harvest technique using a single-port and CO2 insufflation technique can be very useful in breast reconstruction that does not require a skin paddle. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Acidosis induced by carbon dioxide insufflation decreases heparin potency: a risk factor for thrombus formation.

BACKGROUND: Since the introduction of CO2 insufflation during open heart surgery in our hospital, we incidentally observed thrombus formation in the dissected heart, in the pericardium and in the cardiotomy reservoir of the cardiopulmonary bypass system. Furthermore, we measured very high levels of pCO2, causing severe acidosis, in stagnant blood in the pericardium and cardiotomy reservoir. OBJECTIVES: In this in vitro study, we assessed the influence of acidosis and hypothermia on heparin potency and thrombin formation. METHODS: We assessed heparin potency in function of pH (pH 5.0-7.4) and temperature (24-37°C) by comparing the activated partial thromboplastin time in platelet-poor plasma between samples with and without unfractionated heparin. We measured thrombin formation in platelet-poor plasma by means of fluorescent, calibrated, automated thrombography in function of pH (pH 5.0-7.4) and temperature (24-37°C). The parameters of interest were the endogenous thrombin potential and the peak amount of thrombin generation. RESULTS: The major finding of this study is the significant decrease in the efficiency of unfractionated heparin in delaying thrombus formation at acidotic (pH 5.0-7.0) conditions (p=0.034-0.05). Furthermore, we found that thrombin formation is significantly increased at hypothermic (24-34°C) conditions (p=<0.001-0.01). CONCLUSIONS: Based on the results of our in-vitro study, we conclude that acidosis may lead to a decreased heparin potency. Acidosis, as induced by CO2 insufflation, may predispose patients to incidental thrombus formation in stagnant blood in the open thorax and in the cardiotomy reservoir. Hypothermia might further increase this risk. Therefore, we recommend reconsidering the potential advantages and disadvantages of using CO2 insufflation during cardiopulmonary bypass.

Carbon dioxide insufflation during colonoscopy can significantly decrease post-interventional abdominal discomfort in deeply sedated patients: A prospective, randomized, double-blinded, controlled trial.

BACKGROUND AND AIM: CO2 has been reported to be absorbed from the bowel more rapidly than air, resulting in a discomfort reduction after colonoscopy. Its role in deeply sedated patients is limited. This study was designed to investigate the efficacy and safety of CO2 insufflation during colonoscopy in patients deeply sedated with propofol. METHODS: A total of 125 continuous patients were randomly assigned to receive either CO2 (n = 63) or air (n = 62) insufflation during propofol-sedated colonoscopy. Postcolonoscopy abdominal pain, distention, and satisfaction were assessed at 1, 3, and 24 h after the procedure, and the proportions of pain-free and distention-free patients were compared. Residual bowel gas in the colon and small bowel was evaluated at 1 h after colonoscopy. End-tidal CO2 and O2 saturation was measured for safety analysis. RESULTS: There was a significant difference between the two groups regarding the postcolonoscopy abdominal pain, distention, and subjective satisfaction at 1 h (P < 0.001) and 3 h (P < 0.01) after the procedure. Patients' pain and distention at 1 and 3 h after the procedure were significantly lower in the CO2 group (P < 0.01). Residual bowel gas in the colon and small bowel was significantly less in the CO2 group (P < 0.001). There was no significant difference in end-tidal CO2 levels between two groups before, during, and after the procedure. CONCLUSIONS: Compared with air, CO2 insufflation during colonoscopy reduced postcolonoscopy abdominal discomfort and improved patients' satisfaction. It was safe to use CO2 insufflation in deeply sedated colonoscopy.

Comparison of Different Carbon Dioxide Insufflation Rates on Hemodynamic Changes in Laparoscopic Surgeries: A Randomized Controlled Trial.

Introduction The injury and detrimental effects of carbon dioxide (CO2) insufflation during laparoscopic surgeries may be due to the higher flow rates used during insufflation. The aim of our study was to study the effects of different CO2 insufflation flow rates on hemodynamic parameters in laparoscopic surgeries. The secondary objectives were to compare the patient and surgeon satisfaction scores, postoperative shoulder scores, and surgical site pain scores. Methods This prospective, randomized, double-blinded trial was commenced after institutional ethical committee approval and The Clinical Trials Registry- India (CTRI) registration (CTRI 2021/10/037595). Ninety patients scheduled for laparoscopic cholecystectomy were randomly divided into three groups based on CO2 insufflation flow rate by computer-generated random numbers and the sealed envelope method: Group-A: 5 L/min; Group-B: 10 L/min; and Group-C: 15 L/min. General anesthesia was standardized in all three groups. Mean arterial pressure (MAP) and heart rate were recorded at different timelines, which included the arrival in the operating room (T0), just before the induction of anesthesia (T1), at the beginning of pneumoperitoneum (T2), 10 minutes (T3), 20 minutes (T4), 30 minutes (T5), and 60 minutes (T6) after the pneumoperitoneum, at the end of the operation (T7), five minutes (T8), and 15 minutes (T9) after arriving at the recovery room. The patient and surgeon satisfaction scores were assessed on a 5-point Likert scale. The visual analog score (VAS) was used to assess the surgical site pain and shoulder pain every four hours for 24 hours. The continuous data were assessed by one-way analysis of variance (ANOVA), and the categorical data were assessed by the Chi-square test. The sample size was estimated based on a pilot study and using the G Power 3.1.9.2 Program (Universitat Kiel, Germany) calculator. Results There was an increase in the mean arterial pressure (MAP) between the groups 60 min after pneumoperitoneum creation with higher flow rates. The baseline MAP was 85.76± 10.11 in group A, 86.03± 9.79 in group B, and 88.13± 8.46 in group C. At 60 min from the creation of the pneumoperitoneum, the MAP increased significantly from 99.17 ± 9.35 in group A, 102.43 ± 8.24 in group B, to 106.83 ± 8.31 in group C. This was statistically significant with a p-value of 0.004. There was a statistically significant difference in heart rate between the groups 10 minutes after pneumoperitoneum creation. No complications were reported in any of the groups. The postoperative shoulder pain was more severe when higher flows were used at 20 and 24 hours. The surgical site pain was also significantly more for up to 12 hours following surgery with higher flows. Conclusion We conclude that low-flow CO2 insufflation during laparoscopic surgeries is associated with fewer hemodynamic changes, better patient satisfaction scores, and lower postoperative pain scores.

Robotic assited perineal prostatectomy (RAPP) as a new era for anesthesiology: It's effects on hemodynamic parameters and respiratory mechanics.

Robotic-assisted perineal prostatactomy(RAPP) is a new alternative surgical technique, in prostate cancer patients especially with a history of intra-abdominal surgery. The aim of this study is to examine the effects of the challenging patient position and CO2 insufflation in perineal space during RAPP on both hemodynamic parameters and respiratory mechanics. Hemodynamic and respiratory parameters of 30 patients who underwent RAPP and 31 patients who underwent Robotic-assisted laparoscopic prostatectomy (RALP) for prostate cancer between 2017 and 2019 were retrospectively evaluated. Comparison between RAPP and RALP patients showed that anesthesia, surgery and insufflation times were shorter in RAPP patients (p < 0.05). Blood pCO2 level was higher, and the pH decrease was more prominent in the RAPP patients 30 and 60 min after perineal CO2 insufflation (p < 0.05). The mean arterial pressures, driving pressure, Ppeak and Pplato values were statistically higher in the RALP patients and 60 min after insufflation while static and dynamic lung compliance values were found to be lower. Our results showed that blood pCO2 level may severely increase after perineal CO2 insufflation. The fact that respiratory mechanics are less affected despite the difficult patient position for lungs in RAPP patients, the presence of higher CO2 level supports that the perineal CO2 insufflation plays a more important role in increased CO2 level. Considering these changes, especially the sudden increase in the risk of CO2 level, close follow-up and timely intervention by anesthesiology can ensure all changes remain in a clinically safe range.

Detection of increased intracranial pressure in trans-oral robotic thyroidectomy using optic nerve sheath diameter measurement.

BACKGROUND: During transoral robot-assisted thyroidectomy, there is a risk of increasing intracranial pressure because the site of CO2 insufflation is narrow and close to the brain. METHODS: We analyzed the pre- to post-CO2 neck insufflation change in the optic nerve sheath diameter during transoral robot-assisted thyroidectomy. Changes in vital-signs, airway pressure, and arterial carbon dioxide pressure were analyzed along with postoperative complications. RESULTS: Among the 30 participants, the post-CO2 inflation mean optic nerve sheath diameter (5.64 ± 0.54 mm) was higher than the pre-induction diameter (4.81 ± 0.37 mm) with a mean difference of 0.83 (95% CI, 0.69-0.97; p < 0.001), but returned to baseline after CO2 deflation in most cases. One participant had sustained increased optic nerve sheath diameter (6.35 mm) associated with severe new-onset postoperative headache. CONCLUSION: Transient elevation in the intracranial pressure during low-pressure CO2 neck insufflation in the transoral robot-assisted thyroidectomy did not appear to adversely affect patients.

Epicardial access facilitated by carbon dioxide insufflation via intentional coronary vein exit: step-by-step description of the technique and review of the literature.

Pericardial access from a subxiphoid approach is often necessary to gain access to a critical epicardial substrate that is inaccessible from the endocardium. Although relatively safe, a rate of up to 5% of acute and 2% delayed complications has been reported. Intentional perforation of a distal coronary vein branch with pericardial insufflation of CO2 to create a negative contrast space anterior to the right ventricle is an emerging approach to facilitate pericardial access. In this report, we describe the technique of intentional coronary vein exit with CO2 insufflation to perform epicardial mapping and ablation of ventricular tachycardia (VT) in a step-by-step approach and review the published literature on this topic.

A routine de-airing method for total endoscopic robot-assisted mitral valve repair.

Intraoperative water testing is essential for assessing mitral valve morphology and degree of residual mitral regurgitation during mitral valve repair. However, in some cases, evacuating intracardiac air is challenging. Herein, we report the routine de-airing method during total endoscopic robot-assisted mitral valve repair at our institute and discuss its effectiveness. In brief, our de-airing methods involve the following steps: after restricting the blood flow of the cardiopulmonary bypass, intracardiac air was pushed out into the pulmonary veins by drawing blood from the right ventricle. The left atrium, left ventricle, and ascending aorta were filled with blood to remove air from the root cannula. Retrograde blood flow from the coronary sinus was used to remove air from the coronary arteries. At 10 min after cardiopulmonary bypass weaning, transesophageal echocardiography revealed that residual intracardial air was absent in 99% of patients in all three chambers (ascending aorta, left atrium, and left ventricle).

Gasless endoscopic thyroidectomy via modified areola approach with a simple flap-lifting technique.

Objective: Studies have shown that carbon dioxide (CO2) insufflation during endoscopic thyroidectomy is associated with many risks. Recently, we have designed a simple lifting tool using Kirschner wire. We aimed to use this tool for flap-lifting in modified areola approach endoscopic thyroidectomy and compare it with conventional CO2 insufflation. Methods: In a prospective study, patients who underwent endoscopic thyroidectomy via modified areola approach were randomly assigned into gasless (n = 20) or CO2 groups (n = 22). Pre-operative variables included age, gender, tumor diameter, and clinical diagnosis. Intra-operative hemodynamic monitoring included mean arterial pressure, heart rate, pulse oximetry, end-tidal carbon dioxide (ET-CO2) and arterial pH. Other intra-operative details included total operative time, operative blood loss, conversion from endoscopic surgery to open surgery, intra-operative events, and endoscope video score. Postoperatively, the hospital stay, drainage volume, and complications were recoded. Results: Patient characteristics were not different between the two groups. During the operation, ET-CO2 levels were significantly higher in the CO2 group (P < 0.05), whereas arterial pH levels were significantly lower (P < 0.05). The CO2 group had longer operation time and higher endoscope clarity VAS score than gasless group. Hospital stay, drainage volume, and postoperative complications did not differ significantly between the two groups (P > 0.05). Conclusions: The gasless endoscopic thyroidectomy we performed via our Kirschner wire hook was safe, feasible, and yielded good results.

Relief Effect of Carbon Dioxide Insufflation in Transnasal Endoscopy for Health Checks-A Prospective, Double-Blind, Case-Control Trial.

CO2 insufflation has proven effective in reducing patients' pain after colonoscopies but has not been examined in esophagogastroduodenoscopies. Therefore, we examined the effect of CO2 insufflation in examinees who underwent transnasal endoscopies without sedation. This study is a single-center, prospective, double-blind, case-control trial conducted between March 2017 and August 2018. Subjects were assigned weekly to receive insufflation with either CO2 or air. The primary outcome was improvement of abdominal pain and distension at 2 h and 1-day postprocedure. In total, 336 and 338 examinees were assigned to the CO2 and air groups, respectively. Visual analog scale (VAS) scores for abdominal distension (15.4 vs. 25.5; p < 0.001) and distress from flatus (16.0 vs. 28.8; p < 0.001) at 2 h postprocedure were significantly reduced in the CO2 group. VAS scores for pain during the procedure (33.5 vs. 37.1; p = 0.059) and abdominal pain after the procedure (3.9 vs. 5.7; p = 0.052) also tended to be lower at 2 h postprocedure, but all parameters showed no significant difference at 1-day postprocedure. All procedures were safely completed through the planned program, and no apparent adverse events requiring treatment or follow-up occurred. In conclusion, CO2 insufflation may reduce postprocedural abdominal discomfort from transnasal esophagogastroduodenoscopies. (UMIN000028543).

Port-Site Metastasis in Gynecological Malignancies.

BACKGROUND: Minimally invasive oncologic surgery has become the standard of care in many gynecologic cancers. While laparoscopic surgery provides many benefits to patients, such as faster recovery, there are unique challenges associated with minimally invasive techniques. Port-site metastasis is a rare complication after laparoscopic oncologic surgery in management of gynecologic malignancies. METHODS: We present the case of a 44-year-old female with isolated port-site recurrence following laparoscopic radical hysterectomy with node-negative, clinical stage IB1 cervical adenocarcinoma. In addition, we provide an updated review of the literature on management and oncologic outcomes of port-site metastasis. CONCLUSION: Port-site metastasis prevention necessitates a better understanding of underlying risk factors and pathophysiology in order to optimize outcomes. Future studies are needed on risk-reducing strategies and standardization of management for port-site metastasis.

Construction of a computational mechanical model of bronchi for practical simulation of the optimal positive intrathoracic pressure conditions during general thoracic surgery.

BACKGROUND: Thoracic CO2 insufflation with positive intrathoracic pressure is usually effective during thoracoscopic surgery, however, lung collapse is sometimes insufficient. We hypothesized that inappropriate bronchial collapse might cause this unsuccessful lung collapse. OBJECTIVE: The objective of this study was to construct a computational mechanical model of bronchi for practical simulation to discover the optimal conditions of positive intrathoracic pressure during thoracoscopic surgery. METHODS: Micro-focus high-resolution X-ray computed tomography measurements of lungs from just-slaughtered swine were extracted, and the three-dimensional geometries of the bronchi under pressurized and depressurized conditions were measured accurately. The mechanical properties of the bronchus were also measured. Computational fluid dynamics (CFD) and computational structural mechanics (CSM) analyses were conducted. RESULTS: The CSM results indicated that the present structural model could simulate bronchial occlusion. The CFD results showed that airflows from pressed lung alveoli might cause low-internal-pressure regions when suddenly or heterogeneously pushed airflow was injected from a small branching bronchus to a large bronchus. A preliminary computational mechanical model of bronchi was constructed. CONCLUSIONS: We demonstrated the performance of the mechanical model of bronchi in rough simulations of bronchial occlusions. However, this model should be verified further using human data to facilitate its introduction to clinical use.

Fetoscopic insufflation modeled in the extrauterine environment for neonatal development (EXTEND): Fetoscopic insufflation is safe for the fetus.

BACKGROUND: Minimally invasive fetal surgery, or fetoscopy, is an alternative to open fetal surgery to repair common birth defects like myelomeningocele. Although this hysterotomy-sparing approach reduces maternal morbidity, the effects of in utero insufflation on the fetus are poorly understood. Our purpose was to determine the optimal fetal insufflation conditions. METHODS: Fetal sheep at gestational age 104 to 107 days were studied under insufflation conditions in utero and ex utero. The ex utero fetuses were cannulated via their umbilical vessels into a support device, the EXTra-uterine Environment for Neonatal Development (EXTEND). EXTEND fetuses were exposed to four different insufflation conditions for four hours: untreated carbon dioxide (CO2) (n=5), warm humidified (whCO2) (n=4), whCO2 with the umbilical cord exposed (n=3), and whCO2 without amniotic fluid (skin and cord exposed) (n=3). RESULTS: In utero insufflation led to significant increases in fetal CO2 and reductions in fetal pH. Ex utero insufflation with whCO2 did not lead to changes in fetal blood gas measurements or cerebral perfusion parameters. Insufflation with whCO2 with an exposed umbilical cord led to reduced umbilical blood flow. CONCLUSIONS: Insufflation with warm humidified CO2 with an amniotic fluid covered umbilical cord is well tolerated by the fetus without significant changes in hemodynamics or cerebral perfusion parameters. TYPE OF STUDY: Basic science LEVEL OF EVIDENCE: N/A.

Combined single-port transmediastinal and laparoscopic access with CO2 insufflation for esophageal resection: a case report on a canine model.

In order to be familiar with the dissection of the esophagus through a single transmediastinal access. Combined single-port transmediastinal and laparoscopic access with CO2 insufflation for esophageal resection were performed in experimental dogs. The esophagus was separated by single-hole mediastinoscopy, the stomach was separated by laparoscopy, and left neck anastomosis of tubular gastroesophagus was performed on the experimental dogs. Combined single-port transmediastinal and laparoscopic access with the CO2 insufflation is an alternative approach for esophagectomy with certain advantages compared to transthoracic approach. Animal models can help the surgeon get familiar with a certain procedure before transmediastinal esophagectomy on a human.

A strategy for pulmonary resection after contralateral diaphragm plication: a surgical case report.

BACKGROUND: Pulmonary carcinoma patients with low pulmonary function cannot be treated surgically because of the high risk of complications. Diaphragmatic eventration is a disease characterized by diaphragmatic paralysis and dyspnea. Here, we report a surgical case of multiple pulmonary carcinomas with contralateral diaphragmatic eventration. CASE PRESENTATION: The patient was a 75-year-old woman with multiple metachronous right lung carcinomas complicated by left diaphragmatic eventration. When she was 70 years old, a right upper lobectomy and right S6b wedge resection were performed for double lung carcinomas. Five years later, two new lung tumors in her right lower lobe and left diaphragmatic eventration were identified, but resection was thought to be impossible because of her low pulmonary function. We performed video-assisted thoracoscopic surgery (VATS) plication with carbon dioxide (CO2) insufflation for the left diaphragmatic eventration, and her pulmonary function improved. Subsequently, we performed a right S6 wedge resection and right S9 segmentectomy for the double lung tumors with no complications. The tumors were diagnosed as double primary carcinomas. CONCLUSIONS: Our case presented with low pulmonary function and right multiple lung carcinomas with left diaphragmatic eventration. VATS plication for the left diaphragmatic eventration achieved improvement in her pulmonary function, and right pulmonary resection for the lung carcinomas was performed. VATS plication can expand the choice of treatments in such cases.

The Change of Endotracheal Tube Cuff Pressure During Laparoscopic Surgery.

BACKGROUND: We evaluated the endotracheal tube cuff pressure (Pcuff) changes during pneumoperitoneum for laparoscopic cholecystectomy and the correlations between body mass index (BMI), pneumoperitoneum time, and Pcuff changes. METHODS: Total 60 patients undergoing laparoscopic cholecystectomy were allocated to either a study group (BMI ≥ 25 kg/m2) or a control group (BMI < 25 kg/m2). The endotracheal intubation was performed with a high-volume low-pressure cuffed oral endotracheal tube. A manometer was connected to the pilot balloon using a 3-way stopcock and the cuff was inflated. The change in Pcuff was defined as the difference between the pressure just before intra-abdominal CO2 insufflation and the pressure before CO2 desufflation. RESULTS: Pcuff increased to 5.3 ± 3.6 cmH2O in the study group and 5.7 ± 5.4 cmH2O in the control group. There was no significant difference between two groups. While BMI was not correlated with change in Pcuff (r = 0.022, p = 0.867), there was a significant correlation between change in Pcuff and the duration of pneumoperitoneum (r = 0.309, p = 0.016). CONCLUSION: The change in Pcuff was not affected by BMI and was significantly correlated with pneumoperitoneum time. We recommend regular measurement and adjustment of Pcuff during laparoscopic surgery.