The effects of different positions on lower extremity hemodynamics during robot-assisted laparoscopic radical prostatectomy for prostate cancer

PURPOSE

This study aimed to investigate the effects of two different positions on lower extremity hemodynamics during robot-assisted laparoscopic radical prostatectomy (RARP) for prostate cancer.

METHODS

A total of 196 patients who underwent RARP in our hospital from February 2020 to March 2022 were included in this study. Among them, 98 patients who underwent surgery with the Trendelenburg position and split-leg position with calf reverse arch from March 2021 to March 2022 were assigned to the observation group, while 98 patients who underwent surgery with the Trendelenburg position and low lithotomy position from February 2020 to February 2021 were assigned to the control group. Using an ultrasound diagnostic instrument to detect the internal diameter, mean blood flow velocity, and mean blood flow volume of the left deep femoral vein at different times, such as the supine position (T0), after 5 minutes of placing the patient in the leg spilt or low lithotomy position (T1), after 5 minutes of pneumoperitoneum (T2), after 5 minutes of head-down tilt or head-down tilt and calf reverse arch (T3), 1.5 hours after the start of surgery (T4), before the removal of CO2 gas (T5), and before the patient left the operating room (T6). As well as the patency of deep venous blood flow in both lower extremities before leaving the operating room, RESULTS: After establishment of pneumoperitoneum, the internal diameter of the deep femoral vein increased significantly, while the mean blood flow velocity and mean blood flow volume decreased significantly in both groups(T0) (P<0.001). With the prolongation of surgical time, the impact on lower extremity hemodynamics in the observation group was smaller than that in the control group. From T2 to T6, the internal diameter of the femoral vein in the observation group was smaller than that in the control group, while the mean blood flow velocity and mean blood flow volume were increased compared to the control group (P<0.05). Before leaving the operating room, the patency of deep venous blood flow in the observation group was better than that in the control group (P=0.003).

CONCLUSION

Placing patients in the Trendelenburg position and split-leg position with calf reverse arch during RARP for prostate cancer has a smaller impact on lower extremity hemodynamics than the low lithotomy position, and can relatively reduce the risk of postoperative deep vein thrombosis.

[The effect of deep neuromuscular block combined with low pneumoperitoneum pressure on postoperative pain in patients undergoing laparoscopic radical colorectal surgery]

Objective: To investigate the effect of deep neuromuscular blockade (DNMB) combined with low pneumoperitoneum pressure anesthesia strategy on postoperative pain in patients undergoing laparoscopic colorectal surgery. Methods: This study was a randomized controlled trial. One hundred and twenty patients who underwent laparoscopic colorectal surgery at Cancer Hospital of Chinese Academy of Medical Sciences from December 1, 2022 to May 31, 2023 were selected and randomly divided into two groups by random number table method. Moderate neuromuscular blockade [train of four stimulations count (TOFC)=1-2] was maintained in patients of the control group (group C, n=60) and pneumoperitoneum pressure level was set at 15 mmHg(1 mmHg=0.133 kPa). DNMB [post-tonic stimulation count (PTC)=1-2] was maintained in patients of the DNMB combined with low pneumoperitoneum pressuregroup (group D, n=60) and pneumoperitoneum pressure level was set at 10 mmHg. The primary measurement was incidence of moderate to severe pain at 1 h after surgery. The secondary measurements the included incidence of moderate to severe pain at 1, 2, 3, 5 d and 3 months after surgery, the incidence of rescue analgesic drug use, the doses of sufentanil in analgesic pumps, surgical rating scale (SRS) score, the incidence of postoperative residual neuromuscular block, postoperative recovery [evaluated with length of post anesthesia care unit (PACU) stay, time of first exhaust and defecation after surgery and length of hospital stay] and postoperative inflammation conditions [evaluated with serum concentration of interleukin (IL)-1β and IL-6 at 1 d and 3 d after surgery]. Results: The incidence of moderate to severe pain in group D 1 h after surgery was 13.3% (8/60), lower than 30.0% (18/60) of group C (P<0.05). The incidence of rescue analgesia in group D at 1 h and 1 d after surgery were 13.3% (8/60) and 4.2% (5/120), respectively, lower than 30.0% (18/60) and 12.5% (15/120) of group C (both P<0.05). The IL-1β level in group D was (4.1±1.8)ng/L at 1 d after surgery, which was lower than (4.9±2.6) ng/L of group C (P=0.048). The IL-6 level in group D was (2.0±0.7)ng/L at 3 d after surgery, which was lower than (2.4±1.1) ng/L of group C (P=0.018). There was no significant difference in the doses of sufentanil in analgesic pumps, intraoperative SRS score, incidence of neuromuscular block residue, time spent in PACU, time of first exhaust and defecation after surgery, incidence of nausea and vomiting, and length of hospitalization between the two groups (all P>0.05). Conclusion: DNMB combined with low pneumoperitoneum pressure anesthesia strategy alleviates the early-stage pain in patients after laparoscopic colorectal surgery.

The effects of robot-assisted laparoscopic surgery with Trendelenburg position on short-term postoperative respiratory diaphragmatic function

OBJECTIVE

To study how Pneumoperitoneum under Trendelenburg position for robot-assisted laparoscopic surgery impact the perioperative respiratory parameters, diagrammatic function, etc. METHODS: Patients undergoing robot-assisted laparoscopic surgery in the Trendelenburg position and patients undergoing general surgery in the supine position were selected. The subjects were divided into two groups according to the type of surgery: robot-assisted surgery group and general surgery group. ① Respiratory parameters such as lung compliance, oxygenation index, and airway pressure were recorded at 5 min after intubation, 1 and 2 h after pneumoperitoneum. ② Diaphragm excursion (DE) and diaphragm thickening fraction (DTF) were recorded before entering the operating room (T1), immediately after extubation (T2), 10 min after extubation (T3), and upon leaving the postanesthesia care unit (T4). ③ Peripheral venous blood (5 ml) was collected before surgery and 30 min after extubation and was analyzed by enzyme-linked immunosorbent assay to determine the serum concentration of Clara cell secretory protein 16 (CC16) and surfactant protein D (SP-D).

RESULT

① Compared with the general surgery group (N = 42), the robot-assisted surgery group (N = 46) presented a significantly higher airway pressure and lower lung compliance during the surgery(P < 0.001). ② In the robot-assisted surgery group, the DE significantly decreased after surgery (P < 0.001), which persisted until patients were discharged from the PACU (P < 0.001), whereas the DTF only showed a transient decrease postoperatively (P < 0.001) and returned to its preoperative levels at discharge (P = 0.115). In the general surgery group, the DE showed a transient decrease after surgery(P = 0.011) which recovered to the preoperative levels at discharge (P = 1). No significant difference in the DTF was observed among T1, T2, T3, and T4. ③ Both the general and robot-assisted surgery reduced the postoperative serum levels of SP-D (P < 0.05), while the robot-assisted surgery increased the postoperative levels of CC16 (P < 0.001).

CONCLUSION

Robot-assisted laparoscopic surgery significantly impairs postoperative diaphragm function, which does not recover to preoperative levels at PACU discharge. Elevated levels of serum CC16 after surgery suggest potential lung injury. The adverse effects may be attributed to the prolonged Trendelenburg position and pneumoperitoneum during laparoscopic surgery.

The impact of timing, type, and method of instillation of intraperitoneal local anaesthetic in laparoscopic abdominal surgery: a systematic review and network meta-analysis

BACKGROUND

Pain is common after laparoscopic abdominal surgery. Intraperitoneal local anaesthetic (IPLA) is effective in reducing pain and opioid use after laparoscopic surgery, although the optimum type, timing, and method of administration remains uncertain. We aimed to determine the optimal approach for delivering IPLA which minimises opioid consumption and pain after laparoscopic abdominal surgery.

METHODS

MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were systematically searched for randomised controlled trials comparing different combinations of the type (bupivacaine vs lidocaine vs levobupivacaine vs ropivacaine), timing (pre-vs post-pneumoperitoneum at the beginning or end of surgery), and method (aerosol vs liquid) of IPLA instillation in patients undergoing any laparoscopic abdominal surgery. A network meta-analysis was conducted to ascertain the optimum approach for delivering IPLA resulting in the least cumulative opioid consumption and pain (overall and localising to the shoulder) 24 h after surgery. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessments (PROSPERO ID: CRD42022307595).

RESULTS

Twenty-five RCTs were included, among which 15 different combinations of delivering IPLA were analysed across 2401 participants. Aerosolised bupivacaine instilled at the end of surgery, before deflation of the pneumoperitoneum, was associated with significantly less postoperative opioid consumption compared with all other approaches for delivering IPLA (98.7% of comparisons; moderate certainty), aside from liquid levobupivacaine instilled before surgery and during or after creation of the pneumoperitoneum (mean difference -11.6, 95% credible interval: -26.1 to 2.5 i.v. morphine equivalent doses). There were no significant differences between different IPLA approaches regarding overall pain scores and incidence of shoulder pain up to 24 h after surgery.

CONCLUSIONS

There are limited studies and low-quality evidence to conclude on the optimum method of delivering IPLA in laparoscopic abdominal surgery. While aerosolised bupivacaine instilled at the end of surgery but before deflation of the pneumoperitoneum minimises postoperative opioid consumption, pain scores up to 24 h did not differ between the different modalities of delivering IPLA. The generalisability of these results is limited by the lack of utilisation of non-opioid analgesics in most trials.

SYSTEMATIC REVIEW PROTOCOL REGISTRATION

PROSPERO CRD42022307595.

Effect of the new video laryngeal mask airway SaCoVLM on airway management in lateral laparoscopic urological surgery: A single center randomized controlled trial

There are few pertinent studies about the application of laryngeal mask airways (LMAs) in lateral decubitus surgery. Therefore, the aim of our study was to evaluate the effects of lateral position and pneumoperitoneum on oropharyngeal leak pressure (OLP) and ventilation efficiency for the LMA SaCoVLM. Patients undergoing elective retroperitoneal laparoscopic urological surgery were randomized 1:1 to the Supreme group or SaCoVLM group. The primary outcome was the OLP with LMA insertion. The secondary outcomes were the first-attempt success rate, insertion time, adjustment times, gastric tube success rate, LMA alignment accuracy, LMA removal time, regurgitation or aspiration, LMA blood staining, and incidence of adverse events 24 h after surgery. We recruited 70 patients to complete the study. Regardless of lateral position and pneumoperitoneum, the OLP was greater in the SaCoVLM group (n = 35) than in the Supreme group (n = 35), with a median difference of 4-7 cmH2O. The first-attempt success rate of the SaCoVLM group was higher than that of the Supreme group (91.4% vs. 77.1%, risk ratio (RR): 1.19; 95% CI 0.96 to 1.46, P = 0.188). Thus, in the lateral position with pneumoperitoneum, although the new video LMA SaCoVLM has a higher OLP than the LMA Supreme, both devices provide sufficient ventilation efficiency.

Risk mitigation to healthcare workers against viral and bacterial bioaerosol load in laparoscopic surgical exhaust with a new flow mode in hollow fiber membranes-based filter

Laparoscopy of COVID-19-infected/suspected patients needs to be performed with the utmost care due to the chances of virus carryover through the pneumoperitoneum gas. In this study, polysulfone/polyvinyl-pyrrolidone hollow fiber membranes (HFMs) were fabricated by phase inversion process, and these HFMs were bundled into a module consisting of tortuous, circular-helical arrangement. Further, copper (Cu) and zinc (Zn) nanoparticles (NPs), known to have antimicrobial and antiviral properties, were flow-coated on the lumen side of the HFMs. To test functional efficiency, the modules were challenged with wet aerosol and bioaerosols. Wet aerosol removal efficiency was ∼98%. Bioaerosol-containing bacteria E. coli strain K-12, showed 2.6 log (∼99.8%), and 2.1 log (∼99.3%) removal efficiency for Cu NPs and Zn NPs coated HFMs modules, respectively, and 1.6 log (∼97%) removal for plain (uncoated) HFMs. Bioaerosols containing SARS-CoV-2 surrogate virus (MS2 bacteriophage) showed ∼5-7 log reduction of bacteriophage for plain HFMs, 3.9 log, and 2.3 log reduction for Cu and Zn coated HFMs, respectively. The flow of aerosols entirely through the HFM lumen helps in attaining a low ΔP of < 1 mm Hg, thus rendering its usefulness, particularly for exhausting pneumoperitoneum gases where high upstream pressures could lead to barotrauma. STATEMENT OF ENVIRONMENTAL IMPLICATION: Surgical smoke is generated during minimally invasive surgical (MIS) procedure such as laparoscopy when electrosurgical devices are used to cut any tissues. This smoke is a hazard as it contains toxic volatile compounds, mutagens, carcinogens, bacteria, and virus-laden aerosols. Infection to healthcare professionals through the bioaerosols containing smoke is well reported in literature. The limitation of using hypochlorite and pleated/HEPA filter, led us to design a low pressure drop bioaerosol filter, which can remove smoke, tissue fragments, and COVID-19 virus. It provides a much safer operation theatre environment during MIS procedures as well as in general for bioaerosol removal.

Effects of Haemodynamic Changes Caused by Different Pneumoperitoneum Pressures on Cerebral Oxygenation in Laparoscopic Cholecystectomy: Prospective Randomised Controlled Trial

OBJECTIVE

To evaluate the role of different pneumoperitoneum pressure ranges on cerebral oxygenation.

STUDY DESIGN

Prospective, randomised controlled trial. Place and Duration of the Study: Karadeniz Technical University, Turkiye, from January to September 2020.

METHODOLOGY

Seventy patients (aged 18-65 years, ASA I-IIII) scheduled for laparoscopic cholecystectomy were divided into two groups; low pressure (LP, 10-12 mmHg) and high pressure (HP, 13-15 mmHg). The heart rate, peripheral oxygen saturation, systolic, diastolic, and mean arterial pressure, BIS, end-tidal carbon dioxide, and left and right regional cerebral oxygen saturation (rSO2) were recorded during induction, at the beginning, and after 5, 10, 15, 30, 60, and 90th minutes of pneumoperitoneum, after the surgical and anaesthesia procedures.

RESULTS

The findings did not demonstrate a significant difference between the haemodynamic parameters of the groups. However, there were differences (fifth [p=0.022], fifteenth minutes [p=0.035], at the end [p=0038] of pneumoperitoneum in right rSO2, and similarly at the end [p=0.038] of pneumoperitoneum in left rSO2 between mean variation of rSO2 when compared to the baseline; cerebral oxygenation was better preserved in LP. While no patient had more than 20% rSO2 reduction in LP, a total of three patients had cerebral desaturation in HP.

CONCLUSION

Although <15 mmHg pressure for pneumoperitoneum was usually well-tolerated by patients, it had been observed that cerebral oxygenation may be affected with this range. The pathophysiological effects of pneumoperitoneum and possible consequences of this situation should be considered while performing laparoscopy.

KEY WORDS

Cerebrovascular circulation, Haemodynamics, Laparoscopic cholecystectomy, Near- infrared spectroscopy, Pneumoperitoneum.

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

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

Thawed Porcine Model for Surgical Training: A Novel Conservative Procedure

Background: General Surgery course is a mandatory in medical schools and continuing surgery training is important even to experienced surgeons which they need to maintain and/or improve their surgical skills. Additionally, the models used for that practice are human cadavers, anesthetized porcine, or simulators and are not accessible for medicine schools or physicians in many countries. Therefore, we present a new technical procedure for preparation of frozen experimental animal's cadavers for medical surgical training. Materials and Methods: To perform the study, one porcine slaughtered and frozen at -20°C was used. The porcine cadaver was thawed at room temperature (25°C) and then the pneumoperitoneum test was performed and viscera inspection carried out. Results: The porcine cadaver took 20 hours to completely thaw. The pneumoperitoneum was successfully performed with total distention of the abdominal cavity. All viscera were well preserved maintaining important in vivo characteristics for consistency. Conclusion: The use of thawed porcine cadaver as a model to train many surgical procedures including videolaparoscopy is feasible. The tissues were well preserved by this method and was financially accessible and could be used for different techniques, equipment, and material tests.

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

BACKGROUND

Low-pressure pneumoperitoneum (LPP) is an attempt at improving laparoscopic surgery. However, it has the issue of poor working space for which deep neuromuscular blockade (NMB) may be a solution. There is a lack of literature comparing LPP with deep NMB to standard pressure pneumoperitoneum (SPP) with moderate NMB.

METHODOLOGY

This was a single institutional prospective non-inferiority RCT, with permuted block randomization of subjects into group A and B [Group A: LPP; 8-10 mmHg with deep NMB [ Train of Four count (TOF): 0, Post Tetanic Count (PTC): 1-2] and Group B: SPP; 12-14 mmHg with moderate NMB]. The level of NMB was monitored with neuromuscular monitor with TOF count and PTC. Cisatracurium infusion was used for continuous deep NMB in group A. Primary outcome measures were the surgeon satisfaction score and the time for completion of the procedure. Secondarily important clinical outcomes were also reported.

RESULTS

Of the 222 patients screened, 181 participants were enrolled [F: 138 (76.2%); M: 43 (23.8%); Group A n = 90, Group B n = 91]. Statistically similar surgeon satisfaction scores (26.1 ± 3.7 vs 26.4 ± 3.4; p = 0.52) and time for completion (55.2 ± 23.4 vs 52.5 ± 24.9 min; p = 0.46) were noted respectively in groups A and B. On both intention-to-treat and per-protocol analysis it was found that group A was non-inferior to group B in terms of total surgeon satisfaction score, however, non-inferiority was not proven for time for completion of surgery. Mean pain scores and incidence of shoulder pain were statistically similar up-to 7 days of follow-up in both groups. 4 (4.4%) patients in group B and 2 (2.2%) in group A had bradycardia (p = 0.4). Four (4.4%) cases of group A were converted to group B. One case of group B converted to open surgery. Bile spills and gallbladder perforations were comparable.

CONCLUSION

LPP with deep NMB is non-inferior to SPP with moderate NMB in terms of surgeon satisfaction score but not in terms of time required to complete the procedure. Clinical outcomes and safety profile are similar in both groups. However, it could be marginally costlier to use LPP with deep NMB.

Viral load of SARS-CoV-2 in surgical smoke in minimally invasive and open surgery: a single-center prospective clinical trial

At the beginning of the COVID-19 pandemic, it was assumed that SARS-CoV-2 could be transmitted through surgical smoke generated by electrocauterization. Minimally invasive surgery (MIS) was targeted due to potentially higher concentrations of the SARS-CoV-2 particles in the pneumoperitoneum. Some surgical societies even recommended open surgery instead of MIS to prevent the potential spread of SARS-CoV-2 from the pneumoperitoneum. This study aimed to detect SARS-CoV-2 in surgical smoke during open and MIS. Patients with SARS-CoV-2 infection who underwent open surgery or MIS at Heidelberg University Hospital were included in the study. A control group of patients without SARS-CoV-2 infection undergoing MIS or open surgery was included for comparison. The trial was approved by the Ethics Committee of Heidelberg University Medical School (S-098/2021). The following samples were collected: nasopharyngeal and intraabdominal swabs, blood, urine, surgical smoke, and air samples from the operating room. An SKC BioSampler was used to sample the surgical smoke from the pneumoperitoneum during MIS and the approximate surgical field during open surgery in 15 ml of sterilized phosphate-buffered saline. An RT-PCR test was performed on all collected samples to detect SARS-CoV-2 viral particles. Twelve patients with proven SARS-CoV-2 infection underwent open abdominal surgery. Two SARS-CoV-2-positive patients underwent an MIS procedure. The control group included 24 patients: 12 underwent open surgery and 12 MIS. One intraabdominal swab in a patient with SARS-CoV-2 infection was positive for SARS-CoV-2. However, during both open surgery and MIS, none of the surgical smoke samples showed any detectable viral particles of SARS-CoV-2. The air samples collected at the end of the surgical procedure showed no viral particles of SARS-CoV-2. Major complications (CD ≥ IIIa) were more often observed in SARS-CoV-2 positive patients (10 vs. 4, p = 0.001). This study showed no detectable viral particles of SARS-CoV-2 in surgical smoke sampled during MIS and open surgery. Thus, the discussed risk of transmission of SARS-CoV-2 via surgical smoke could not be confirmed in the present study.

Pressure-controlled ventilation-volume guaranteed mode improves bronchial mucus transport velocity in patients during laparoscopic surgery for gynecological oncology: a randomized controlled study

BACKGROUND

Mechanical ventilation during general anesthesia may impair airway mucosal function. This study aimed to investigate the effect of pressure-controlled ventilation-volume guaranteed (PCV-VG) on bronchial mucus transport velocity (BTV) in patients during laparoscopic surgery for gynecological oncology compared with volume controlled ventilation (VCV).

METHODS

66 patients undergoing elective a laparoscopic surgery for gynecological oncology. The patients were randomized into two group receiving either PCV-VG or VCV. a drop of methylene blue was placed on the surface of the airway mucosa under the bronchoscopeand, then the distance the dye movement was measured after 2, 4, and 6 min. Outcomes were assessed at T0 (5 min after endotracheal intubation and before initiation of pneumoperitoneum), T1 and T2 (1 and 2 h after stabilization of pneumoperitoneum respectively). BTV at T0, T1 and T2 was the primary outcome. Secondary outcomes included heart rate (HR), mean arterial pressure (MAP), body temperature, end-tidal CO2 pressure (PETCO2), tidal volume(VT), peak inspiratory pressure (PIP), mean inspiratory pressure (Pmean), respiratory rate (RR), and dynamic compliance (CDyn) at T0, T1, and T2.

RESULTS

64 patients were included in the analysis. The median [interquartile range] BTV was significantly lower in VCV group at T1 and T2 that at T0 (P < 0.05). Furthermore, BTV was slightly reduced in PCV-VG compared with VCV. BTV in PCV-VG was significantly decreased at T2 compared with BTV at T0 (P < 0.05) and slightly decreased at T1 compared with T0(P > 0.05). Compared with the PCV-VG group, BTV in VCV group significantly decreased at T2 (P < 0.05). No participants experienced respiratory complications.

CONCLUSIONS

PCV-VG is more suitable for patients undergoing laparoscopic surgery for gynecological oncology than VCV since it can protect mucociliary clearance function.

TRIAL REGISTRATION

This trial is registered on https://www.chictr.org.cn/ in Chinese Clinical Trial Registry (ChiCTR.2200064564: Date of registration 11/10/2022).

The effects of positive end-expiratory pressure (PEEP) application on optic nerve sheath diameter in patients undergoing laparoscopic cholecystectomy: a randomized trial

BACKGROUND

Positive end-expiratory pressure (PEEP) can overcome respiratory changes that occur during pneumoperitoneum application in laparoscopic procedures, but it can also increase intracranial pressure. We investigated PEEP vs. no PEEP application on ultrasound measurement of optic nerve sheath diameter (indirect measure of increased intracranial pressure) in laparoscopic cholecystectomy.

METHODS

Eighty ASA I-II patients aged between 18 and 60 years scheduled for elective laparoscopic cholecystectomy were included. The study was registered in the Australian New Zealand Clinical Trials (ACTRN12618000771257). Patients were randomly divided into either Group C (control, PEEP not applied), or Group P (PEEP applied at 10 cmH20). Optic nerve sheath diameter, hemodynamic, and respiratory parameters were recorded at six different time points. Ocular ultrasonography was used to measure optic nerve sheath diameter.

RESULTS

Peak pressure (PPeak) values were significantly higher in Group P after application of PEEP (p = 0.012). Mean respiratory rate was higher in Group C at all time points after application of pneumoperitoneum (p < 0.05). The mean values of optic nerve sheath diameters measured at all time points were similar between the groups (p > 0.05). The pulmonary dynamic compliance value was significantly higher in group P as long as PEEP was applied (p = 0.001).

CONCLUSIONS

During laparoscopic cholecystectomy, application of 10 cmH2O PEEP did not induce a significant change in optic nerve sheath diameter (indirect indicator of intracranial pressure) compared to no PEEP application. It would appear that PEEP can be used safely to correct respiratory mechanics in cases of laparoscopic cholecystectomy, with no significant effect on optic nerve sheath diameter.

Effects of individualised positive end-expiratory pressure titration on respiratory and haemodynamic parameters during the Trendelenburg position with pneumoperitoneum: A randomised crossover physiologic trial

BACKGROUND

The Trendelenburg position with pneumoperitoneum during surgery promotes dorsobasal atelectasis formation, which impairs respiratory mechanics and increases lung stress and strain. Positive end-expiratory pressure (PEEP) can reduce pulmonary inhomogeneities and preserve end-expiratory lung volume (EELV), resulting in decreased inspiratory strain and improved gas-exchange. The optimal intraoperative PEEP strategy is unclear.

OBJECTIVES

To compare the effects of individualised PEEP titration strategies on set PEEP levels and resulting transpulmonary pressures, respiratory mechanics, gas-exchange and haemodynamics during Trendelenburg position with pneumoperitoneum.

DESIGN

Prospective, randomised, crossover single-centre physiologic trial.

SETTING

University hospital.

PATIENTS

Thirty-six patients receiving robot-assisted laparoscopic radical prostatectomy.

INTERVENTIONS

Randomised sequence of three different PEEP strategies: standard PEEP level of 5 cmH 2 O (PEEP 5 ), PEEP titration targeting a minimal driving pressure (PEEP ΔP ) and oesophageal pressure-guided PEEP titration (PEEP Poeso ) targeting an end-expiratory transpulmonary pressure ( PTP ) of 0 cmH 2 O.

MAIN OUTCOME MEASURES

The primary endpoint was the PEEP level when set according to PEEP ΔP and PEEP Poeso compared with PEEP of 5 cmH 2 O. Secondary endpoints were respiratory mechanics, lung volumes, gas-exchange and haemodynamic parameters.

RESULTS

PEEP levels differed between PEEP ΔP , PEEP Poeso and PEEP5 (18.0 [16.0 to 18.0] vs. 20.0 [18.0 to 24.0]vs. 5.0 [5.0 to 5.0] cmH 2 O; P  < 0.001 each). End-expiratory PTP and lung volume were lower in PEEP ΔP compared with PEEP Poeso ( P  = 0.014 and P  < 0.001, respectively), but driving pressure, lung stress, as well as respiratory system and dynamic elastic power were minimised using PEEP ΔP ( P  < 0.001 each). PEEP ΔP and PEEP Poeso improved gas-exchange, but PEEP Poeso resulted in lower cardiac output compared with PEEP 5 and PEEP ΔP .

CONCLUSION

PEEP ΔP ameliorated the effects of Trendelenburg position with pneumoperitoneum during surgery on end-expiratory PTP and lung volume, decreased driving pressure and dynamic elastic power, as well as improved gas-exchange while preserving cardiac output.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00028559, date of registration 2022/04/27). https://drks.de/search/en/trial/DRKS00028559.

Evaluation of the Effect of Pressure-Controlled Ventilation-Volume Guaranteed Mode vs. Volume-Controlled Ventilation Mode on Atelectasis in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Clinical Trial

Background and Objectives: Laparoscopic surgery, which results in less bleeding, less postoperative pain, and better cosmetic results, may affect the lung dynamics via the pneumoperitoneum. After laparoscopic surgery, atelectasis develops. The primary aim of the present study is to demonstrate the effects of two different ventilation modes on the development of atelectasis using lung ultrasound, and the secondary outcomes include the plateau pressure, peak inspiratory pressure, and compliance differences between the groups. Materials and Methods: In this study, 62 participants aged 18-75 years undergoing laparoscopic cholecystectomy were enrolled. The patients were randomly assigned into two groups: the volume-controlled ventilation (VCV) group (group V) or the pressure-controlled-volume guaranteed ventilation (PCV-VG) group (group PV). The lung ultrasound score (LUS) was obtained thrice: prior to induction (T1), upon the patient's initial arrival in the recovery room (T2), and just before departing the recovery unit (T3). The hemodynamic data and mechanical ventilation parameters were recorded at different times intraoperatively. Results: The LUS score was similar between the groups at all the times. The change in the LUS score of the right lower anterior chest was statistically higher in the VCV group than the PCV group. The peak inspiratory pressure (PIP) was found to be statistically higher in the V group than the PV group five minutes after induction (T5) (20.84 ± 4.32 p = 0.021). The plateau pressure was found to be higher in the V group than the PV group at all times (after induction (Tind) 17.29 ± 5.53 p = 0.004, (T5) 17.77 ± 4.89 p = 0.001, after pneumoperitoneum (TPP) 19.71 ± 4.28 p = 0.002). Compliance was found to be statistically higher in the PV group than the V group at all times ((Tind) 48.87 ± 15.37 p = 0.011, (T5) 47.94 ± 13.71 p = 0.043, (TPP) 35.65 ± 6.90 p = 0.004). Before and after the pneumoperitoneum, the compliance was determined to be lower in the V group than the PV group, respectively (40.68 ± 13.91 p = 0.043, 30.77 ± 5.73 p = 0.004). Conclusions: LUS score was similar between groups at all times. The PCV-VG mode was superior to the VCV mode in providing optimal ventilatory pressures and maintaining high dynamic compliance in patients undergoing laparoscopic abdominal surgery.

Comparison of surgical outcomes between robot-assisted laparoscopic hysterectomy and conventional total laparoscopic hysterectomy in gynecologic benign disease: a single-center cohort study

We compared the surgical outcomes of robot-assisted laparoscopic hysterectomy (RAH) and total laparoscopic hysterectomy (TLH). This single-center cohort study compared 139 RAH cases from January, 2017 to September, 2021 and 291 TLH cases between January, 2015 and December, 2020. We retrospectively evaluated surgical outcomes, including total operative time (defined as the time from port wound incision to port wound closure), net operative time (defined as the time from the start of pneumoperitoneum to the end of pneumoperitoneum), estimated blood loss, weight of excised uterus (±adnexa), and overall complications, and the relationship between surgeon experience and operative time, net operative time, and blood loss in RAH and TLH. There was no significant difference in the total operative time between the two groups. Regardless of surgeon experience, the net operative time was significantly shorter in the RAH group than in the TLH group (p <0.001) and the estimated blood loss was significantly lower in RAH cases than in TLH cases (p = 0.01). The net operative time per uterine weight was shorter in the TLH group than that in the RAH group; however, there was no significant difference. RAH resulted in statistically better surgical outcomes in terms of net operative time and blood loss, regardless of surgeon experience. However, net operative time and blood loss also seem to be significantly affected by uterus weight. Large trials are imperative to determine the more effective surgical approach between RAH and TLH for different patient subsets.

Preoperative Optimization for Abdominal Wall Reconstruction

Patients requiring abdominal wall reconstruction may have medical comorbidities and/or complex defects. Comorbidities such as smoking, diabetes, obesity, cirrhosis, and frailty have been associated with an increased risk of postoperative complications. Prehabilitation strategies are variably associated with improved outcomes. Large hernia defects and loss of domain may present challenges in achieving fascial closure, an important part of restoring abdominal wall function. Prehabilitation of the abdominal wall can be achieved with the use of botulinum toxin A, and preoperative progressive pneumoperitoneum.

Bilateral inguinal hernia repair by laparoscopic totally extraperitoneal (TEP) vs. laparoscopic transabdominal preperitoneal (TAPP)

BACKGROUND

The guidelines recommend laparoscopic repair for bilateral inguinal hernia. However, few studies compare the totally extraperitoneal (TEP) and transabdominal preperitoneal (TAPP) techniques in bilateral inguinal hernias. This study aimed to compare the outcomes of TEP and TAPP in bilateral inguinal hernia.

METHODS

We conducted a retrospective cohort study of patients operated on for bilateral inguinal hernia by TEP and TAPP repair from 2016 to 2020. Intraoperative complications, operative time, acute postoperative pain, hospital stay, postoperative complications, chronic inguinal pain, and recurrence were compared.

RESULTS

A total of 155 patients were included in the study. TEP was performed in 71 patients (46%) and TAPP in 84 patients (54%). The mean operative time was longer in the TAPP group than in the TEP group (107 min vs. 82 min, p < 0.001). The conversion rate to open surgery was higher in the TEP group than in the TAPP group (8.5% vs. 0%, p = 0.008). The mean hospital stay was longer in the TAPP group than in the TEP group (p < 0.001). We did not observe significant differences in the proportion of postoperative complications (p = 0.672), postoperative pain at 24 h (p = 0.851), chronic groin pain (p = 0.593), and recurrence (p = 0.471). We did not observe an association between the choice of surgical technique (TEP vs. TAPP) with conversion rate, operative time, hospital stay, postoperative complications, chronic inguinal pain, or hernia recurrence when performing a multivariable analysis adjusted for the male sex, age, BMI, ASA, recurrent hernia repair, surgeon, and hernia size > 3cm.

CONCLUSIONS

Bilateral inguinal hernia repair by TEP and TAP presented similar outcomes in our study.

Individualized Positive End-expiratory Pressure Titration Strategies in Superobese Patients Undergoing Laparoscopic Surgery: Prospective and Nonrandomized Crossover Study

BACKGROUND

Superobesity and laparoscopic surgery promote negative end-expiratory transpulmonary pressure that causes atelectasis formation and impaired respiratory mechanics. The authors hypothesized that end-expiratory transpulmonary pressure differs between fixed and individualized positive end-expiratory pressure (PEEP) strategies and mediates their effects on respiratory mechanics, end-expiratory lung volume, gas exchange, and hemodynamic parameters in superobese patients.

METHODS

In this prospective, nonrandomized crossover study including 40 superobese patients (body mass index 57.3 ± 6.4 kg/m2) undergoing laparoscopic bariatric surgery, PEEP was set according to (1) a fixed level of 8 cm H2O (PEEPEmpirical), (2) the highest respiratory system compliance (PEEPCompliance), or (3) an end-expiratory transpulmonary pressure targeting 0 cm H2O (PEEPTranspul) at different surgical positioning. The primary endpoint was end-expiratory transpulmonary pressure at different surgical positioning; secondary endpoints were respiratory mechanics, end-expiratory lung volume, gas exchange, and hemodynamic parameters.

RESULTS

Individualized PEEPCompliance compared to fixed PEEPEmpirical resulted in higher PEEP (supine, 17.2 ± 2.4 vs. 8.0 ± 0.0 cm H2O; supine with pneumoperitoneum, 21.5 ± 2.5 vs. 8.0 ± 0.0 cm H2O; and beach chair with pneumoperitoneum; 15.8 ± 2.5 vs. 8.0 ± 0.0 cm H2O; P < 0.001 each) and less negative end-expiratory transpulmonary pressure (supine, -2.9 ± 2.0 vs. -10.6 ± 2.6 cm H2O; supine with pneumoperitoneum, -2.9 ± 2.0 vs. -14.1 ± 3.7 cm H2O; and beach chair with pneumoperitoneum, -2.8 ± 2.2 vs. -9.2 ± 3.7 cm H2O; P < 0.001 each). Titrated PEEP, end-expiratory transpulmonary pressure, and lung volume were lower with PEEPCompliance compared to PEEPTranspul (P < 0.001 each). Respiratory system and transpulmonary driving pressure and mechanical power normalized to respiratory system compliance were reduced using PEEPCompliance compared to PEEPTranspul.

CONCLUSIONS

In superobese patients undergoing laparoscopic surgery, individualized PEEPCompliance may provide a feasible compromise regarding end-expiratory transpulmonary pressures compared to PEEPEmpirical and PEEPTranspul, because PEEPCompliance with slightly negative end-expiratory transpulmonary pressures improved respiratory mechanics, lung volumes, and oxygenation while preserving cardiac output.

EDITOR’S PERSPECTIVE

Sánchez-Margallo F, Eugenia Candanosa-Aranda I, Poelaert J, Castellanos G, L. N. G. Malbrain M. The pathophysiological impact of intra-abdominal hypertension in pigs

BACKGROUND

Intra-abdominal hypertension and abdominal compartment syndrome are common with clinically significant consequences. We investigated the pathophysiological effects of raised IAP as part of a more extensive exploratory animal study. The study design included both pneumoperitoneum and mechanical intestinal obstruction models.

METHODS

Forty-nine female swine were divided into six groups: a control group (Cr; n = 5), three pneumoperitoneum groups with IAPs of 20mmHg (Pn20; n = 10), 30mmHg (Pn30; n = 10), 40mmHg (Pn40; n = 10), and two mechanical intestinal occlusion groups with IAPs of 20mmHg (MIO20; n = 9) and 30mmHg (MIO30; n = 5).

RESULTS

There were significant changes (p<0.05) noted in all organ systems, most notably systolic blood pressure (SBP) (p<0.001), cardiac index (CI) (p = 0.003), stroke volume index (SVI) (p<0.001), mean pulmonary airway pressure (MPP) (p<0.001), compliance (p<0.001), pO2 (p = 0.003), bicarbonate (p = 0.041), hemoglobin (p = 0.012), lipase (p = 0.041), total bilirubin (p = 0.041), gastric pH (p<0.001), calculated glomerular filtration rate (GFR) (p<0.001), and urine output (p<0.001). SVV increased progressively as the IAP increased with no obvious changes in intravascular volume status. There were no significant differences between the models regarding their impact on cardiovascular, respiratory, renal and gastrointestinal systems. However, significant differences were noted between the two models at 30mmHg, with MIO30 showing worse metabolic and hematological parameters, and Pn30 and Pn40 showing a more rapid rise in creatinine.

CONCLUSIONS

This study identified and quantified the impact of intra-abdominal hypertension at different pressures on several organ systems and highlighted the significance of even short-lived elevations. Two models of intra-abdominal pressure were used, with a mechanical obstruction model showing more rapid changes in metabolic and haematological changes. These may represent different underlying cellular and vascular pathophysiological processes, but this remains unclear.

Preoperative Abdominal Muscle Elongation Facilitated Laparoscopic Intraperitoneal Onlay Mesh Repair of Complex Ventral Hernia

Background: Complex ventral hernia remains a challenging situation for any surgeon. In this study, our aim was to analyze the effect of laparoscopic intraperitoneal onlay mesh (IPOM) repair in the treatment of complex abdominal wall hernia, with the assistance of preoperative progressive pneumoperitoneum (PPP) and botulinum toxin A (BTA). Methods: In this retrospective study, we included 13 patients with complex ventral hernia between May 2021 and December 2022. All patients undergoing PPP and BTA protocol before hernia repair. The length of abdominal wall muscles and abdominal circumference were measured from CT scan. All hernias were repaired with laparoscopic or laparoscopic-assisted IPOM. Results: Thirteen patients received PPP and BTA injections. PPP and BTA administration time was over 8.8 ± 2.5 days. Before and after PPP and BTA, imaging showed that the length of lateral muscle on each side increased from 14.3 to 17.4 cm (P < .05). The abdominal circumference increased from 81.8 to 87.9 cm (P < .05). Complete fascial closure was obtained in 13 patients (100%), and no patient experienced postoperative abdominal hypertension and ventilatory support. No patient suffered from recurrent hernia to date. Conclusions: Preoperative PPP combined with BTA injection plays a role similar to component separation technique, avoids the abdominal hypertension after laparoscopic IPOM repair of complex ventral hernia.

Management of abdominal gas leakage from surgical trocars in laparoscopic surgery: a preclinical study

Introduction: There is an ongoing concern about the potential infectious risk due to pneumoperitoneal gas leakage from surgical trocars in laparoscopic surgery. We aimed to visually confirm the presence of leakage from trocars and investigate the changes in the leakage scale according to intra-abdominal pressures and trocar types. Material and methods: We established a porcine pneumoperitoneum model and performed experimental forceps manipulation using 5-mm grasping forceps with 12-mm trocars. The gas leakage, if any, was imaged using a Schlieren optical system, which can visualize minute gas flow invisible to the naked eye. For measuring the scale, we calculated the gas leakage velocity and area using image analysis software. Four types of unused and exhausted disposable trocars were compared. Results: Gas leakage was observed from trocars during forceps insertion and removal. Both the gas leakage velocity and area increased as the intra-abdominal pressure increased. Every type of trocar we handled was associated with gas leakage, and exhausted disposable trocars had the largest scale gas leakage. Conclusions: We confirmed gas leakage from trocars during device traffic. The scale of leakage increased with high intra-abdominal pressure and with the use of exhausted trocars. Current protection against gas leakage may not be sufficient and new surgical safety measures and device development may be needed in the future.

MRI measurement of the effects of moderate and deep neuromuscular blockade on the abdominal working space during laparoscopic surgery, a clinical study

BACKGROUND

Conflicting data exist regarding the effects of deep neuromuscular blockade (NMB) on abdominal dimensions during laparoscopic procedures. We performed a clinical study to establish the influence of moderate and deep neuromuscular blockade (NMB) on the abdominal working space, measured by Magnetic Resonance Imaging (MRI), during laparoscopic donor nephrectomy with standard pressure (12 mmHg) pneumoperitoneum under sevoflurane anaesthesia.

METHODS

Ten patients were intraoperatively scanned three times in the lateral decubitus position, with pneumoperitoneum maintained by a mobile insufflator. The first scan without NMB (T1) was followed by scans with moderate (T2) and deep NMB (T3). The skin-sacral promontory (S-SP) distance was measured, and 3D pneumoperitoneum volumes were reconstructed.

RESULTS

The mean difference in the S-SP distance was -0.32 cm between T2 and T3 (95% CI -1.06 - 0.42 cm; p = 0.344) and + 2.1 cm between T1 and T2 (95% CI 0.81 - 3.39 cm; p = 0.006). The mean differences in pneumoperitoneum volume were 166 mL between T2 and T3 (95% CI, 5 - 327 mL; p = 0.044) and 108 mL between T1 and T2 (95% CI, -273 - 488 mL; p = 0.525). The pneumoperitoneum volume showed high inter-individual variability and no increase in three patients with a high volume at T1.

CONCLUSIONS

During laparoscopic surgery in the lateral decubitus position with standard pressure under sevoflurane anaesthesia, deep NMB did not increase the S-SP distance compared to moderate NMB. Moderate NMB increased the S-SP distance by a mean of 2.1 cm (15.2%) compared with no NMB. The mean pneumoperitoneum volume increased slightly from moderate to deep NMB, with high inter-individual variability.

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT03287388.