High intra-abdominal pressure during experimental laparoscopic liver resection reduces bleeding but increases the risk of gas embolism

Low Pneumoperitoneum Pressure Reduces Gas Embolism During Laparoscopic Liver Resection: A Randomized Controlled Trial

OBJECTIVE

To compare the effect of low and standard pneumoperitoneal pressure (PP) on the occurrence of gas embolism during laparoscopic liver resection (LLR).

BACKGROUND

LLR has an increased risk of gas embolism. Although animal studies have shown that low PP reduces the occurrence of gas embolism, clinical evidence is lacking.

METHODS

This parallel, dual-arm, double-blind, randomized controlled trial included 141 patients undergoing elective LLR. Patients were randomized into standard ("S," 15 mm Hg; n = 70) or low ("L," 10 mm Hg; n = 71) PP groups. Severe gas embolism (≥ grade 3, based on the Schmandra microbubble method) was detected using transesophageal echocardiography and recorded as the primary outcome. Intraoperative vital signs and postoperative recovery profiles were also evaluated.

RESULTS

Fewer severe gas embolism cases (n = 29, 40.8% vs n = 47, 67.1%, P = 0.003), fewer abrupt decreases in end-tidal carbon dioxide partial pressure, shorter severe gas embolism duration, less peripheral oxygen saturation reduction, and fewer increases in heart rate and lactate during gas embolization episodes was found in group L than in group S. Moreover, a higher arterial partial pressure of oxygen and peripheral oxygen saturation were observed, and fewer fluids and vasoactive drugs were administered in group L than in group S. In both groups, the distensibility index of the inferior vena cava negatively correlated with central venous pressure throughout LLR, and a comparable quality of recovery was observed.

CONCLUSIONS

Low PP reduced the incidence and duration of severe gas embolism and achieved steadier hemodynamics and vital signs during LLR. Therefore, a low PP strategy can be considered a valuable choice for the future LLR.

Cerebral infarction by paradoxical gas embolism detected after laparoscopic partial hepatectomy with an insufflation management system: a case report

BACKGROUND

Laparoscopic surgery has reduced surgical morbidity and postoperative duration of hospital stay. Gas embolism is commonly known as a risk factor for all laparoscopic procedures. We report a case of severe cerebral infarction presumably caused by paradoxical CO₂ embolism in laparoscopic partial hepatectomy with an insufflation management system.

CASE PRESENTATION

A male in his 60 s was diagnosed with recurrence of liver metastasis in the right hepatic lobe after laparoscopic lower anterior resection for rectal cancer. We performed laparoscopic partial hepatectomy with an AirSeal® under 10 mmHg of intra-abdominal pressure. During the surgery, the patient's end-tidal CO₂ and percutaneous oxygen saturation dropped from approximately 40-20 mmHg and 100-90%, respectively, while the heart rate increased from 60 to 120 beats/min; his blood pressure remained stable. Postoperatively, the patient developed right hemiplegia and aphasia. Brain magnetic resonance imaging showed cerebral infarction in the broad area of the left cerebral cortex. Thereafter, transesophageal echocardiography revealed a patent foramen ovale, suggesting cerebral infarction due to paradoxical gas embolism.

CONCLUSIONS

A patent foramen ovale is found in approximately 15-20% of healthy individuals. While gas embolism is a rare complication of laparoscopic surgery, cerebral infarction must be considered a possible complication even if the intra-abdominal pressure is constant under 10 mmHg with an insufflation management system.

The preoperative M2BPGi score predicts operative difficulty and the incidence of postoperative complications in laparoscopic liver resection

BACKGROUND

Liver fibrosis or cirrhosis frequently makes parenchymal transection more difficult, but the difficulty score of laparoscopic liver resection (LLR), including the IWATE criteria, does not include a factor related to liver fibrosis. Therefore, this study aimed to evaluate M2BPGi as a predictor of the difficulty of parenchymal transection and the incidence of postoperative complications in LLR.

METHODS

Data from 54 patients who underwent laparoscopic partial liver resection (LLR-P) and 24 patients who underwent laparoscopic anatomical liver resection between 2017 and 2019 in our institution were retrospectively analyzed. All cases were classified according to M2BPGi scores, and reserve liver function, intraoperative blood loss, and postoperative complications were compared among these groups.

RESULTS

Sixteen cases (29.6%) were M2BPGi negative (cut-off index < 1.0), 25 cases (46.3%) were 1+ (1.0 ≤ cut-off index < 3.0), and 13 cases (24.1%) were 2+ (cut-off index ≥ 3.0). M2BPGi-positive cases had significantly worse hepatic reserve function (K-ICG: 0.16 vs 0.14 vs 0.08, p < 0.0001). Intraoperative bleeding was significantly greater in M2BPGi-positive cases [50 ml vs 150 ml vs 200 ml, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.045]. Postoperative complications (Clavien-Dindo ≥ II) were significantly more frequent in M2BPGi-positive cases [0% vs 4% vs 33%, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.001].

CONCLUSION

M2BPGi could predict surgical difficulty and complications in LLR-P. In particular, it might be better not to select M2BPGi (2+) cases as teaching cases because of the massive bleeding during parenchymal transection.

Effects of Retroperitoneal or Transperitoneal Pneumoperitoneum on Inferior Vena Cava Hemodynamics and Cardiopulmonary Function: A Prospective Real-Time Comparison

Objective: To evaluate the effects of CO₂ pneumoperitoneum on venous hemodynamics and cardiopulmonary function during transperitoneal or retroperitoneal laparoscopic surgery. Materials and Methods: A single-institution prospective study. Forty-three patients with renal-cell carcinoma undergoing retroperitoneal (22) or transperitoneal (21) laparoscopic partial nephrectomy were enrolled. Hemodynamic functions were monitored by minimally invasive FloTrac/Vigileo system. Transesophageal echocardiography was used to measure the diameter and blood flow of the inferior vena cava (IVC). Measured parameters were recorded at baseline, 10, 30, 60 minutes following insufflation to 14 mm Hg and 10 minutes following desufflation. Results: For hemodynamic changes in the transperitoneal laparoscopic surgery (TPL) and retroperitoneal laparoscopic surgery (RPL), transperitoneal CO₂ insufflation resulted in a rapid parallel increase in central intravenous pressure (CVP), peak airway pressure (AWP), and IVC blood flow velocity after the first 30 minutes of pneumoperitoneum (p < 0.05). In contrast, CVP, AWP, and IVC blood flow velocity increased progressively in RPL. The variation of those parameters was significantly lower than that of TRL (p < 0.001; p = 0.002; p = 0.004). The mean maximum CVP in the two groups was 20 and 16 mm Hg, respectively. The IVC diameter at the cavoatrial junction was significantly reduced in TPL after 10 minutes of insufflation, but it remained unchanged in RPL throughout the surgery. For cardiopulmonary function changes, heart output decreased after a short period of pneumoperitoneum, but no statistical differences were observed between the two groups. The increments of partial pressure of arterial carbon dioxide and end-tidal carbon dioxide tension were significantly higher in RPL than TPL (p < 0.001; p < 0.001). Conclusions: Compared with retroperitoneal pneumoperitoneum, transperitoneal pneumoperitoneum has significant effects on IVC hemodynamics. Elevated intra-abdominal pressure (IAP) causes higher AWP and venous return resistance, which lead to the significant increase of CVP during transperitoneal approach. Adjusting the balance between IAP and CVP might be an effective way to control intravenous bleeding. Clinical Trial Registry: Registration number: ChiCTR2000038291.

Impact of AirSeal® insufflation system on respiratory and circulatory dynamics during laparoscopic abdominal surgery

The effect of the AirSeal^® insufflation system on hemodynamic parameters, especially end-tidal carbon dioxide (EtCO₂), during laparoscopic abdominal surgery remains unclear. This retrospective single-center study included 333 consecutive patients who underwent laparoscopic hepatectomy (n = 43), gastrectomy (n = 69), colectomy (n = 137), or proctectomy (n = 84) using the AirSeal^®. Patient demographics and intraoperative hemodynamic parameters, such as EtCO₂, peripheral capillary oxygen saturation (SpO₂), and arterial systolic blood pressure (ABP), were collected and analyzed. EtCO₂ was evaluated during the entire operative period (whole period) as well as the pneumoperitoneum period until specimen removal (pneumoperitoneum period). We defined “positive respiratory and circulatory responses” (positive responses) as a decrease in EtCO₂ ≥ 3 mmHg in addition to decreases in SpO₂ ≥ 3% and ABP ≥ 10 mmHg simultaneously, which suggest possible carbon dioxide (CO₂) embolism. The median EtCO₂ values of hepatectomy, gastrectomy, colectomy, and proctectomy in the whole period/pneumoperitoneum period were 37.3/37.4, 37.1/37.3, 37.4/37.9, and 38.2/38.4 mmHg, respectively. The EtCO₂ of proctectomy was significantly higher than that of gastrectomy during the whole and pneumoperitoneum periods (P < 0.05). In contrast, the EtCO₂ of hepatectomy was comparable to that of the other three surgeries in the whole and pneumoperitoneum periods. Meanwhile, nine (2.7%; eight hepatectomies and one proctectomy) patients showed positive responses, and one who underwent a partial hepatectomy developed a clinically manifested CO₂ embolism. Positive responses occurred during venous exposure or bleeding in all nine cases. Although the EtCO₂ of hepatectomy was comparable to that of the other surgeries using the AirSeal^®, laparoscopic hepatectomy showed a tendency of CO₂ embolism. Thus, a secure and careful surgical approach is mandatory for laparoscopic hepatectomy using the AirSeal^® insufflation system.

Lower vs standard pressure pneumoperitoneum in robotic-assisted radical prostatectomy: a systematic review and meta-analysis

Robotic-assisted laparoscopic radical prostatectomy (RARP) has been traditionally performed at a pneumoperitoneum insufflation pressure of 12-15 mmHg. This meta-analysis and systematic review aims to assess the current evidence comparing lower to standard pressure pneumoperitoneum in RARP. Systematic searches of MEDLINE, COCHRANE, SCOPUS and EMBASE were performed to identify articles published up until November 2021 comparing lower pressure with standard pressure pneumoperitoneum in RARP. Standard pressure was defined as > 12 mmHg and lower pressure ≤ 12 mmHg. Estimated blood loss, length of operation, length of hospital stay, post-operative ileus, 30-day readmissions, Clavien-Dindo complications and rate of positive surgical margins were extracted as endpoints of interest. Our searches identified 165 abstracts of which 4 articles with 1319 patients were eligible. Cumulative analysis demonstrated reduced length of stay when a lower pressure was used: WMD - 0.23 (- 0.45 to - 0.02) days (p = 0.03) as well as a reduced rate of post-operative ileus: OR 0.41 (0.22 to 0.77) (p = 0.006). There was no significant increase in length of operation WMD - 1.79 (- 15.96 to 12.38) (p = 0.8), estimated blood loss WMD - 2.89 (- 29.41 to 23.62) (p = 0.83), 30-day readmissions or positive surgical margins OR 1.04 (0.78 to 1.38) (p = 0.81) and RD - 0.01 (- 0.04 to 0.01) (p = 0.3) when using a lower pressure. We have demonstrated reduced length of stay and rates of post-operative ileus, when performing RARP at a lower pressure without a significant increase in length of operation, estimated blood loss, positive surgical margins or complications. The recommendation to use lower pressure pneumoperitoneum is moderate to weak and more randomised control trials are required to validate these results.

Strategic response to bleeding in laparoscopic hepato-pancreato-biliary surgery: an intraoperative checklist

BACKGROUND

The aim is to develop and test the utility of an event-initiated, team-based check list to optimize the response to bleeding during laparoscopic HPB surgery.

METHODS

To build a checklist for managing bleeding events, we conducted a systematic review. Using nominal group technique (NGT), a checklist consisting of four domains was developed. Following team-based training of anesthesia and surgical staff, the checklist was implemented. HPB cases before and after implementation of the checklist were compared for adverse outcomes, bleeding complications, and transfusions.

RESULTS

NGT identified four domains: Communicate Control, Expose, and Repair under which the checklist was organized. Supplemental Video for a detailed review of how each domain was applied to a specific case example. We compared 169 HPB cases before to 53 cases after implementation. We found a significant decrease in mean EBL (from 518 ± 852.8 to 151.5 ± 221.7 ml (P = 0.001)) for cases performed after implementation of the checklist and a trends toward less volume of pRBC transfused (2.7 ± 2.5 vs 2.3 ± 1.7 units/per patient, P = 0.611) and transfusion rates (22% vs 11%, P = 0.703).

CONCLUSION

An event-initiated, team-based response to an adverse bleeding event during laparoscopic HPB surgery correlates with positive effects on bleeding management, and transfusion rates.

Paradoxical carbon dioxide embolism during laparoscopic hepatectomy without intracardiac shunt: A case report

BACKGROUND

Laparoscopic hepatectomy has recently become popular because it results in less bleeding than open hepatectomy. However, CO₂ embolism occurs more frequently. Most CO₂ embolisms during laparoscopic surgery are self-resolving and non-symptomatic; however, severe CO₂ embolism may cause hypotension, cyanosis, arrhythmia, and cardiovascular collapse. In particular, paradoxical CO₂ embolisms are highly likely to cause neurological deficits. We report a case of paradoxical CO₂ embolism found on transesophageal echocardiography (TEE) during laparoscopic hepatectomy, although the patient had no intracardiac shunt.

CASE SUMMARY

A 71-year-old man was admitted for laparoscopic left hemihepatectomy. During left hepatic vein ligation, the inferior vena cava was accidentally torn. We observed a sudden drop in oxygen saturation to 85%, decrease in systolic blood pressure (SBP) below 90 mmHg, and reduction in end-tidal CO₂ to 24 mmHg. A “mill-wheel” murmur was auscultated over the precordium. The fraction of inspired oxygen was increased to 100% with 5 cmH₂O of positive end-expiratory pressure (PEEP) and hyperventilation was maintained. Norepinephrine infusion was increased to maintain SBP above 90 mmHg. A TEE probe was inserted, revealing gas bubbles in the right side of the heart, left atrium, left ventricle, and ascending aorta. The surgeon reduced the pneumoperitoneum pressure from 17 to 14 mmHg and repaired the damaged vessel laparoscopically. Thereafter, the patient’s hemodynamic status stabilized. The patient was transferred to the intensive care unit, recovering well without complications.

CONCLUSION

TEE monitoring is important to quickly determine the presence and extent of embolism in patients undergoing laparoscopic hepatectomy.

Short-term outcomes of laparoscopic versus open liver resection for hepatocellular carcinoma in older patients: a propensity score matching analysis

Background

The incidence of hepatocellular carcinoma (HCC) requiring surgical treatment in older patients has been continuously increasing. This study aimed to examine the safety and feasibility of performing laparoscopic liver resection (LLR) versus open liver resection (OLR) for HCC in older patients at a Japanese institution.

Methods

Between January 2010 and June 2021, 133 and 145 older patients (aged ≥ 70 years) who were diagnosed with HCC underwent LLR and OLR, respectively. Propensity score matching (PSM) analysis with covariates of baseline characteristics was performed. The intraoperative and postoperative data were evaluated in both groups.

Results

After PSM, 75 patients each for LLR and OLR were selected and the data compared. No significant differences in demographic characteristics, clinical data, and operative times were observed between the groups, although less than 10% of cases in each group underwent a major resection. Blood loss (OLR: 370 mL, LLR: 50 mL; P < 0.001) was lower, and the length of postoperative hospital stay (OLR: 12 days, LLR: 7 days; P < 0.001) and time to start of oral intake (OLR: 2 days, LLR: 1 day; P < 0.001) were shorter in the LLR group than in the OLR group. The incidence of complications ≥ Clavien–Dindo class IIIa was similar between the two groups.

Conclusions

LLR, especially minor resections, is safely performed and feasible for selected older patients with HCC.

The risk factors of intraoperative conversion during laparoscopic hepatectomy: a systematic review and meta-analysis

PURPOSE

Intraoperative conversion to laparotomy is a challenge during laparoscopic hepatectomy; however, the risk factors of conversion have been poorly elucidated.

METHODS

In this systematic review and meta-analysis, we computed pooled odds ratios (ORs) with 95% confidence intervals (CIs) for each risk factor and evaluated heterogeneity using a L'Abbe plot, Galbraith radial plot, Cochran's Q test, and I². An extended funnel plot was used to evaluate the robustness of the results of meta-analysis. Sensitivity analysis and subgroup analysis were performed to determine sources of heterogeneity. Egger's test and Begg's test were used to assess publication bias.

RESULTS

A total of 25 eligible studies were enrolled in the meta-analysis. Higher body mass index (OR 1.346, 95% CI 1.055-1.717), hypertension (OR 1.387, 95% CI 1.100-1.749), male sex (OR 1.278, 95% CI 1.072-1.523), cirrhosis (OR 1.378, 95% CI 1.062-1.788), major resection (OR 2.041, 95% CI 1.748-2.382), posterosuperior tumor location (OR 2.420, 95% CI 1.923-3.044), and larger tumor diameter (OR 1.618, 95% CI 1.270-2.061) were found to be significantly related to intraoperative conversion during laparoscopic hepatectomy. Malignant tumor (OR 1.253, 95% CI 0.970-1.619), higher American Society of Anesthesiologists stage (OR 1.186, 95% CI 0.863-1.631), multiple tumors (OR 1.273, 95% CI 0.866-1.871), and abdominal surgery history (OR 1.236, 95% CI 0.589-2.597) were not associated with conversion. A history of abdominal surgery showed significant heterogeneity with an I² of 80.8% (p < 0.001). Subgroup analysis indicated that heterogeneity was caused by the different number of patients among enrolled studies.

CONCLUSIONS

In this systematic review and meta-analysis, we identified a number of factors associated with intraoperative conversion during laparoscopic hepatectomy. Our findings can help patient risk evaluation to reduce the laparotomy conversion rate in laparoscopic hepatectomy.

New 5-mm laparoscopic pneumodissector device to improve laparoscopic dissection: an experimental study of its safety in a swine model

BACKGROUND

To improve the laparoscopic surgical dissection, the aim of the study was to assess the safety of burst of high-pressure CO₂ using a 5-mm laparoscopic pneumodissector (PD) operating at different flow rates and for different operating times regarding the risk of gas embolism (GE) in a swine model.

METHODS

The first step was to define the settings use of the PD device ensuring no GE. Successive procedures were conducted by laparotomy: cholecystectomy, the PD was placed 10 mm deep in the liver and the PD was directly introduced into the lumen of the inferior vena cava. Different PD flow rates of 5, 10, and 15 mL/s were used. The second step was to assess the safety of the device (PD group) during a laparoscopic dissection task (cystic and hepatic pedicles dissection, cholecystectomy and right nephrectomy) in comparison with the use of a standard laparoscopic hook device (control group). PD flow rate was 10 mL/s and consecutive burst of high-pressure CO₂ was delivered for 3-5 s.

RESULTS

In the first step (n = 17 swine), no GE occurred during cholecystectomy regardless of the PD flow rate used. When the PD was placed in the liver or into the inferior vena cava, no severe or fatal GE occurred when a burst of high-pressure CO₂ was applied for 3 or 5 s with PD flow rates of 5 and 10 mL/s. In the second step (PD group, n = 10; control group, n = 10), no GE occurred in the PD group. The use of the PD did not increase operative time or blood loss. The quality of the dissection was significantly improved compared to the control group.

CONCLUSIONS

The 5-mm laparoscopic PD appears to be free from CO₂ GE risk when consecutive bursts of high-pressure CO₂ are delivered for 3-5 s with a flow rate of 10 mL/s.

OUP accepted manuscript

Background

Natural orifice specimen extraction (NOSE) is a technique that involves collecting a specimen for extraction through a natural opening avoiding a mini-laparotomy incision. The aim of this study was to compare NOSE and transabdominal specimen extraction in laparoscopic (LAP) colorectal cancer surgery for postoperative outcomes and oncological safety.

Method

A systematic search was conducted in five electronic databases from inception till October 2020. Articles were selected based on the inclusion criteria (studies comparing LAP and NOSE colorectal surgeries reporting at least one of the outcomes) and analysed. Primary outcomes included postoperative complications, pathological results (resection margins and lymph node collection), and oncological outcomes. Secondary outcomes included operating time, blood losses, use of analgesics, functional recovery, duration of hospital stay, and cosmetic results. Fixed and random-effect models were used to measure the pooled estimates.

Results

Nineteen studies involving a total of 3432 participants were analysed (3 randomized clinical trials (RCTs) and 16 retrospective non-randomized studies). Pooled results showed significantly reduced postoperative complications (OR 0.54; 95 per cent c.i. 0.44 to 0.67; P < 0.00001). Pathological outcomes of NOSE were comparable to LAP with no significant difference noted in terms of resection margins (P > 0.05) and lymph node collection (weighted mean difference (WMD) −0.47; 95 per cent c.i. −0.94 to 0; P = 0.05). Pooled analysis demonstrated comparable long-term outcomes in terms of cancer recurrence (OR 0.94; 95 per cent c.i. 0.63 to 1.39; P = 0.75), 5-year disease-free survival (HR 0.97; 95 per cent c.i. 0.73 to 1.29; P = 0.83), and overall survival (HR 0.93, 95 per cent c.i. 0.58 to −1.51; P = 0.78). Finally, the NOSE group had decreased use of additional analgesia after surgery and earlier resumption of oral intake when compared with LAP (respectively OR 0.28; 95 per cent c.i. 0.20 to 0.37; P < 0.00001 and WMD −0.35; 95 per cent c.i. −0.54 to −0.15; P = 0.0005).

Conclusion

This meta-analysis showed that in comparison with LAP, NOSE decreases severe postoperative morbidity while improving postoperative recovery without compromising oncological safety, but it is limited by the small number of RCTs performed in this field.

Minimally invasive mesohepatectomy for centrally located liver lesions-a case series

BACKGROUND

Resection of centrally located liver lesions remains a technically demanding procedure. To date, there are limited data on the effectiveness and safety of minimally invasive mesohepatectomy for benign and malignant lesions. It was therefore the objective of this study to evaluate the perioperative outcomes of minimally invasive mesohepatectomy for liver tumors at a tertiary care hospital.

METHODS

Consecutive patients who underwent a minimally invasive anatomic mesohepatectomy using a Glissonean pedicle approach from April 2018 to November 2021 were identified from a prospective database. Demographics, operative details, and postoperative outcomes were analyzed using descriptive statistics for continuous and categorical variables.

RESULTS

A total of ten patients were included, of whom five patients had hepatocellular carcinoma, one patient had cholangiocarcinoma, three patients had colorectal liver metastases, and one patient had a hydatid cyst. Two and eight patients underwent robotic-assisted and laparoscopic resections, respectively. The median operative time was 393 min (interquartile range (IQR) 298-573 min). Conversion to laparotomy was required in one case. The median lesion size was 60 mm and all cases had negative resection margins on final histopathological analysis. The median total blood loss was 550 ml (IQR 413-850 ml). One patient had a grade III complication. The median length of stay was 7 days (IQR 5-12 days). Time-to-functional recovery was achieved after a median of 2 days (IQR 1-4 days). There were no readmissions within 90 days after surgery.

CONCLUSION

Minimally invasive mesohepatectomy is a feasible and safe approach in selected patients with benign and malignant liver lesions.

Gas embolism under standard versus low pneumoperitoneum pressure during laparoscopic liver resection (GASES): study protocol for a randomized controlled trial

Background

Gas embolism induced by CO₂ pneumoperitoneum is commonly identified as a risk factor for morbidity, especially cardiopulmonary morbidity, after laparoscopic liver resection (LLR) in adults. Increasing pneumoperitoneum pressure (PP) contributes to gas accumulation following laparoscopy. However, few studies have examined the effects of PP in the context of LLR. In LLR, the PP-central venous pressure (CVP) gradient is increased due to hepatic vein rupture, hepatic sinusoid exposure, and low CVP management, which together increase the risk of CO₂ embolization. The aim of this study is to primarily determine the role of low PP (10 mmHg) on the incidence of severe gas embolism.

Methods

Adult participants (n = 140) undergoing elective LLR will be allocated to either a standard (15 mmHg) or low (10 mmHg) PP group. Anesthesia management, postoperative care, and other processes will be performed similarly in both groups. The occurrence of severe gas embolism, which is defined as gas embolism ≥ grade 3 according to the Schmandra microbubble method, will be detected by transesophageal echocardiography (TEE) and recorded as the primary outcome. The subjects will be followed up until discharge and followed up by telephone 1 and 3 months after surgery. Postoperative outcomes, such as the Post-Operative Quality of Recovery Scale, pain severity, and adverse events, will be assessed. Serum cardiac markers and inflammatory factors will also be assessed during the study period. The correlation between intraoperative inferior vena cava-collapsibility index (IVC-CI) under TEE and central venous pressure (CVP) will also be explored.

Discussion

This study is the first prospective randomized clinical trial to determine the effect of low versus standard PP on gas embolism using TEE during elective LLR. These findings will provide scientific and clinical evidence of the role of PP.

Trial status

Protocol version: version 1 of 21-08-2020

Trial registration

ChiCTR2000036396 (http://www.chictr.org.cn). Registered on 22 August 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05678-8.

Paradoxical carbon dioxide embolism during laparoscopic surgery without intracardiac right-to-left shunt: two case reports and a brief review of the literature

We herein report two cases of paradoxical carbon dioxide (CO₂) embolism during laparoscopic nephrectomy and hepatic left lateral lobectomy without evidence of a right-to-left shunt or obvious rupture of blood vessels. Transesophageal echocardiography detected paradoxical CO₂ embolism before the end-tidal CO₂ partial pressure (P_ETCO₂) dropped from baseline. The pneumoperitoneum was reduced or stopped immediately after detection of the embolism. One patient developed a postoperative epileptiform seizure. In the other patient, many gas bubbles were drawn out from the central venous line. We speculate that rapid introduction of pneumoperitoneum pushed a large amount of CO₂ into the abdominal blood vessels, exceeding the gas exchange capacity of the lung and causing CO₂ bubble formation in the left-side cardiac system. These two cases indicate that intraoperative transesophageal echocardiography can reduce the influence of CO₂ embolism during laparoscopic tumor surgery by early diagnosis of the embolism and provide helpful information to establish a list of differential diagnoses of postoperative complications.

Laparoscopic anterior hepatic transection for resecting lesions originating in the paracaval portion of the caudate lobe (with videos)

BACKGROUND

The paracaval portion of the caudate lobe is located in the core of the liver. Lesions originating in the paracaval portion often cling to or even invade major hepatic vascular structures. The traditional open anterior hepatic transection approach has been adopted to treat paracaval-originating lesions. With the development of laparoscopic surgery, paracaval-originating lesions are no longer an absolute contraindication for laparoscopic liver resection. This study aimed to evaluate the safety and feasibility of laparoscopic anterior hepatic transection for resecting paracaval-originating lesions.

METHODS

This study included 15 patients who underwent laparoscopic anterior hepatic transection for paracaval-originating lesion resection between August 2017 and April 2020. The perioperative indicators, follow-up results, operative techniques and surgical indications were retrospectively evaluated.

RESULTS

All patients underwent laparoscopic anterior hepatic transection for paracaval-originating lesion resection. The median operation time was 305 min (220-740 min), the median intraoperative blood loss was 400 ml (250-3600 ml), and the median length of postoperative hospital stay was 9 days (5-20 days). No conversion to laparotomy or perioperative deaths occurred. Six patients had Clavien grade III-IV complications (III/IV, 5/1). Two patients developed tumor recurrence after 13 months and 8 months.

CONCLUSION

Although technically challenging, laparoscopic anterior hepatic transection is still a safe and feasible procedure for resecting paracaval-originating lesions in select patients.

The Effect of Mechanical Ventilation With Low Tidal Volume on Blood Loss During Laparoscopic Liver Resection: A Randomized Controlled Trial

BACKGROUND

Control of bleeding during laparoscopic liver resection (LLR) is important for patient safety. It remains unknown what the effects of mechanical ventilation with varying tidal volumes on bleeding during LLR. Thus, this study aims to investigate whether mechanical ventilation with low tidal volume (LTV) reduces surgical bleeding during LLR.

METHODS

In this prospective, randomized, and controlled clinical study, 82 patients who underwent scheduled LLR were enrolled and randomly received either mechanical ventilation with LTV group (6-8 mL/kg) along with recruitment maneuver (once/30 min) without positive end-expiratory pressure (PEEP) or conventional tidal volume (CTV; 10-12 mL/kg) during parenchymal resection. The estimated volume of blood loss during parenchymal resection and the incidence of postoperative respiratory complications were compared between 2 groups.

RESULT

The estimated volume of blood loss (median [interquartile range {IQR}]) was decreased in the LTV group compared to the CTV group (301 [148, 402] vs 394 [244, 672] mL, P = .009); blood loss per cm2 of transected surface of liver (5.5 [4.1, 7.7] vs 12.2 [9.8, 14.4] mL/cm2, P < .001) and the risk of clinically significant estimated blood loss (>800 mL) were reduced in the LTV group compared to the CTV group (0/40 vs 8/40, P = .003). Blood transfusion was decreased in the LTV group compared to the CTV group (5% vs 20% of patients, P = .043). No patient in the LTV group but 2 patients in the CTV group were switched from LLR to open hepatectomy. Airway plateau pressure was lower in the LTV group compared to the CTV group (mean ± standard deviation [SD]) (12.7 ± 2.4 vs 17.5 ± 3.5 cm H2O, P = .002).

CONCLUSIONS

Mechanical ventilation with LTV may reduce bleeding during laparoscopic liver surgery.

Carbon dioxide: the cause of devastating stroke without hemodynamic compromise during laparoscopic nephrectomy with injury of the inferior vena cava: A case report

RATIONALE

Carbon dioxide pneumoperitoneum in laparoscopic surgery can bring about occult perioperative cerebral infarction, advancing our understanding of the causes of severe postoperative delayed recovery.

PATIENT CONCERNS

Here, we report the case of a 35-year-old woman who underwent a right renal tumor resection in our institution, during which a raised pneumoperitoneum pressure (from 15 to 20 mm Hg) was adopted by the surgeon to prevent errhysis and to help stop the bleeding. Despite an accidental minor tearing of the inferior vena cava, vital signs remained stable throughout the procedure, and no obvious abnormality was observed in either end tidal carbon dioxide values or blood gas analysis. However, the patient unexpectedly suffered delayed recovery after the operation, presenting incomplete left hemiplegia and a positive Babinski sign.

DIAGNOSES

Perioperative stroke was diagnosed by anesthesiologists, after excluding the effects of anesthesia. Cerebral hemorrhage was excluded, as no obvious abnormality was found in the density of brain parenchyma in the emergency computed tomography examination, and a digital subtraction angiography showed no abnormal thrombosis. Further magnetic resonance diagnosis led us to consider diffuse gas embolisms to be the cause of this acute stroke; a right echocardiography revealed that a patent foramen ovale (PFO) may account for the global cerebral gas embolisms.

INTERVENTIONS

The patient received neuroprotective drugs (Vinpocetine, Edaravone, and Xingnaojing, which are commonly used as a standard of care in China), antiplatelets and other symptomatic treatments, plus dexamethasone to relieve edema. A contrast-enhanced echocardiography of the right heart was performed, the results of which were consistent with the sonography of a PFO.

OUTCOMES

The patient was hospitalized for 14 days and eventually discharged after recovery. At the latest follow-up in August 2019, the patient recovered without residual neurological sequelae.

LESSONS

Our results emphasize the need for vigilance regarding adverse cardiovascular and neurological events caused by carbon dioxide gas embolisms when encountering the inadvertent situation of vessels rupturing. Timely monitoring of paradoxical gas embolism by transoesophageal echocardiography is necessary and can avert the risk of severe complications. Urgent consideration should be given to stopping pneumoperitoneum and switching to laparotomy for hemostasis so that the patient can obtain the best benefit-risk ratio.

Surgical Resection: Old Dog, Any New Tricks?

Patients with hepatocellular carcinoma (HCC) have many treatment options. For patients with surgical indication, consideration of future liver remnant and the surgical complexity of the procedure is essential. A new 3-level complexity classification categorizing 11 liver resection procedures predicts surgical complexity and postoperative morbidity better than reported classifications. Preoperative portal vein embolization can mitigate the risk of hepatic insufficiency. For small HCCs, both liver resection and ablation are effective. New medical treatment options are promising and perioperative use of these drugs may further improve outcomes for patients undergoing liver resection and lead to changes in current treatment guidelines.

Feasibility of totally laparoscopic pylorus-preserving gastrectomy with intracorporeal gastro-gastrostomy for early gastric cancer: a retrospective cohort study

Background

Pylorus-preserving gastrectomy (PPG) has been accepted as a function-preserving surgery for the treatment of early gastric cancer in East Asian countries. Therefore, this study aimed to evaluate the feasibility and safety of totally laparoscopic PPG (TLPPG) with intracorporeal anastomosis.

Methods

A total of 43 patients with early gastric cancer underwent laparoscopy-assisted PPG (LAPPG) with extracorporeal anastomosis between May 2006 and November 2012. The operative outcomes of 22 patients who underwent TLPPG between November 2012 and February 2019 were evaluated, and data were compared with that of the LAPPG group.

Results

No significant difference in the operative time was observed between the two groups. Blood loss was lower in the TLPPG group (18.5 mL) than in the LAPPG group (30.7 mL, p = 0.008), and the length of abdominal incision was shorter in the TLPPG group (3.8 cm) than in the LAPPG group (4.7 cm, p < 0.001). No significant difference in the complication rate was observed between the two groups (13.6% in the TLPPG vs. 9.3% in the LAPPG group, p = 0.594). No anastomosis-related complications occurred in either group. No significant between-group difference was observed in the delayed gastric emptying (TLPPG, 9.1 vs. LAPPG, 7%, p = 0.762). The initiation of postoperative fluid (TLPPG, 1.0 day vs. LAPPG, 3.0 days, p < 0.001) and meal (TLPPG, 3.0 days vs. LAPPG, 4.0 days, p < 0.001) intake was earlier in the TLPPG group than in the LAPPG group. No significant between-group difference was observed in the postoperative hospital stay.

Conclusions

The findings of this study suggest that TLPPG with intracorporeal reconstruction not only is as feasible and safe as LAPPG for the treatment of patients with early gastric cancer but also provides certain advantages such as reduced blood loss and wound size.

Robotic versus open pancreaticoduodenectomy: a meta-analysis of short-term outcomes

BACKGROUND

Although robotic surgery is popular around the world, its safety and efficacy over classical open surgery is still controversial. The purpose of this article is to compare the safety and efficacy of robotic pancreaticoduodenectomy (RPD) and open pancreaticoduodenectomy (OPD).

METHODS

A literature search of PubMed, Web of Science, and the Cochrane Library database up to July 29, 2018 was performed and the meta-analysis was performed using RevMan 5.2 software with Fixed and random effects models applied. The IRB approval and written consent were not needed for this paper.

RESULTS

Twelve non-randomized retrospective studies and 1 non-randomized prospective study consisting of 2403 patients were included in this meta-analysis. There were 788 (33%) patients in the RPD group and 1615 (67%) patients in the OPD group. Although RPD was associated with a longer operative time (weighted mean difference [WMD]: 71.74 min; 95% CI 23.37-120.12; p = 0.004), patient might benefit from less blood loss (WMD: - 374.03 ml; 95% CI - 506.84 to - 241.21; p < 0.00001), shorter length of stay (WMD: - 5.19 day; 95% CI - 8.42 to - 1.97; p = 0.002), and lower wound infection rate (odds ratio: 0.17; 95% CI 0.04-0.80; p = 0.02). No statistically significant difference was observed in positive margin rate, lymph nodes harvested, postoperative complications, reoperation or readmission rate, and mortality rate.

CONCLUSIONS

Robotic pancreaticoduodenectomy is a safe and feasible alternative to open pancreaticoduodenectomy with regard to short-term outcomes. Further studies on the long-term outcomes of these surgical techniques are needed.

Possible underestimation of blood loss during laparoscopic hepatectomy

Background

Previous studies have documented potential advantages of laparoscopic hepatectomy in decreasing blood loss compared with open surgery. This study aimed to compare intraoperative blood loss estimated using four different methods in open versus laparoscopic hepatectomy.

Methods

Patients undergoing liver resection between 2014 and 2017 were evaluated prospectively, differentiating between the laparoscopic and open approach. Groups were compared using univariable and multivariable analyses. Intraoperative blood loss was estimated using three formulas based on the postoperative decreases in haematocrit, haemoglobin or red blood cell volume, and using the conventional method of the sum of suction fluid amounts and gauze weight. In addition, blood loss per hepatic transection area was calculated to compare groups.

Results

Some 125 patients who underwent hepatectomy were selected, including 56 open hepatectomies and 69 laparoscopic liver resections. Intraoperative blood loss per hepatic transection area estimated by the conventional method was significantly less in the laparoscopic than the open group (3·6 (range 0·2-50·0) versus 6·6 (1·2-82·5) ml/cm² respectively; P < 0·001). In contrast, there were no significant differences between groups in blood loss estimated based on the decrease in haematocrit (12·9 (0-65·2) versus 8·1 (0-123·7) ml/cm²; P = 0·818), haemoglobin or red blood cell volume. Blood loss estimation using three formulas showed significant linear correlations with the blood loss estimated by the conventional method in the open group (r _s = 0·758 to 0·762), but not in the laparoscopic group (r _s = -0·019 to 0·031).

Conclusion

The conventional method of calculating blood loss in laparoscopic hepatectomy can underestimate losses.

Venous carbon dioxide embolism during laparoscopic cholecystectomy a literature review

Laparoscopy has become the procedure of choice for routine gallbladder removal. A serious complication of this technique is the occurrence of gas emboli due to insufflation. It is associated with a high mortality rate of around 28%. The present systematic review intends to provide more insight into causes, symptoms and risk factors for this specific complication and to explore which measures should be taken to treat and prevent it. The Cochrane library and Pubmed were used as sources. Articles and their references were selected when they were related to the subject in sufficient detail. The course of this complication can vary from asymptomatic up to impairment of normal flow through the right ventricle (RV) or pulmonary artery, potentially leading to acute heart failure. The severity depends on the amount of gas, the rate of accumulation and the ability to remove the gas bubbles. It is difficult to estimate the true incidence of venous gas embolism during laparoscopic cholecystectomy as there are various diagnostic tools, each with different sensitivity. Precautions that need to be taken are: correct positioning of the needle, low insufflation pressure, low insufflation speed, screening for hypovolemia, Trendelenburg positioning, availability of intervention equipment at operation table, no placement of venous catheters during inspiration and catheter removing during expiration. Physicians need to be more aware of this harmful complication and the preventative measurements that need to be taken. As there are virtually no prospective data, future studies are needed to gain more knowledge on gas emboli during laparoscopic cholecystectomy.

Laparoscopic Versus Open Hepatectomy in Short- and Long-Term Outcomes of the Hepatocellular Carcinoma Patients with Cirrhosis: A Systematic Review and Meta-Analysis

Background: Laparoscopic hepatectomy (LH) has been reported as a safe and efficacious treatment for hepatocellular carcinoma (HCC) patients. However, in cirrhosis patients, LH may be more complex and challenging. So, the short- and long-term outcomes should be well evaluated between LH and open hepatectomy (OH) in HCC patients with cirrhosis. Objectives: To compare the short- and long-term outcomes of LH with OH in HCC patients with cirrhosis. Materials and Methods: The PubMed, EMBASE, and Web of Science were systematically searched to identify the clinical trials published until July 2018 on the comparison of LH and OH in HCC patients with cirrhosis. The statistical analysis was conducted by the Review Manager 5.3 (Cochrane Collaboration, Oxford, United Kingdom). Short-term outcomes included blood loss, operation time, blood transfusion, postoperative complications, mortality, postoperative hospital stay, tumor size, and surgical margin. Long-term outcomes included 1-, 3-, 5-year overall survival (OS) and 1-, 3-, 5-year disease-free survival (DFS). Results: Seventeen studies with 2004 patients were included in this meta-analysis. For short-term outcomes, LH suggested less blood loss, lower blood transfusion rates, reduced occurrence of postoperative complications, wider surgical margin, shorter postoperative hospital stay, and declined rate of mortality (all P < .05). However, there was no significant difference in operation time (P = .67) between the two groups, whereas tumor size was larger in OH (P = .004). As to long-term outcomes, 1-, 3-, 5-year OS and 1-year DFS were higher in LH group (all P < .05). Nevertheless, there were no significant differences in 3- and 5-year DFS (P = .23 and .83, respectively). Conclusions: For the HCC patients with cirrhosis, current evidence suggests that LH shows not only better outcomes in short term, but also a comparable and even improved long-term prognosis.

Laparoscopic liver resection: a review of current indications and surgical techniques

Laparoscopic liver resection (LLR) has been the most impressive development in the field of liver surgery in recent two decades. Technical innovations and experience accumulation have made LLR a safe and effective procedure with faster postoperative recovery. Despite the fast spreading of the procedure, details regarding the indications, oncological outcomes and technical essentials were still disputable. To address these issues, two international consensus conferences were hold to update the knowledge in this field. The statements of the both conferences were not conclusive and more high-quality researches are required. In this article, we reviewed the development and the current state of LLR. Indications, outcomes, surgical techniques and devices used in LLR were also discussed.

Randomized clinical trial comparing the effects of sevoflurane and propofol on carbon dioxide embolism during pneumoperitoneum in laparoscopic hepatectomy

Laparoscopic hepatectomy carries a high risk of gas embolism due to the extensive hepatic transection plane and large hepatic vena cava. Here, we compared the influence of inhaled and intravenous anesthetics on gas embolism during laparoscopic hepatectomy. Fifty patients undergoing laparoscopic hepatectomy were divided into two groups to receive sevoflurane anesthesia (group S, n = 25) or intravenous propofol anesthesia (group p, n = 25). During the operation, gas emboli were detected by transesophageal echocardiography and graded according to their size. Venous CO₂ emboli were detected in all patients, and the embolism grades did not differ between the two groups. However, the mean embolism episode duration was longer in group S than group P (51.24±23.59 vs. 34.00±17.13 sec, p < 0.05). At the point of the most severe gas embolism, the PT_CO2 was higher in group S than group p (44.00±4.47 vs. 41.36±2.77 mmHg, p < 0.05), while the PO₂/FiO₂ (450.52±54.08 vs. 503.80±63.18, p < 0.05) and pH values (7.35±0.05 vs. 7.38±0.02, p < 0.05) were lower in group S than group P. Patients with a history of abdominal surgery or liver cirrhosis had higher gas embolism grades. Thus volatile anesthetics may lengthen the duration of embolism episodes and worsen hemodynamics and pulmonary blood gas exchange during surgery.

Posttraumatic venous gas in the liver - a case report and review of the current literature

Background

There are numerous causes of hepatic gas formation that range from serious pathologies to incidental findings, including mesenteric infarction, liver abscess, inflammatory bowel disease or minimally invasive hepatic interventions.

Case presentation

We report a case of a 50-year-old man who was admitted to the emergency room after a car accident. The clinical examination and further diagnostics revealed a craniocerebral injury with a fracture of the skull, concomitant soft tissue lesions and subarachnoidal bleeding. Furthermore, a blunt thoracic trauma with hemopneumothorax due to rib fractures was treated with a chest tube. No obvious abdominal pathology was seen. While in the operating theatre for the surgical revision of the cranial soft tissue lesions, a femoral venous catheter was inserted without any complications. A routine ultrasound of the abdomen six hours after the trauma revealed unclear hepatic gas formation. A contrast-enhanced computer tomography (CT) scan of the abdomen was performed, and the gas formation was found to be localized within the left hepatic vein. Afterwards, there was no specific treatment of the hepatic venous gas formation, as no alterations of liver function or liver enzymes were seen. The further course of the patient was uneventful regarding the gas formation in the liver, and another ultrasound two days later revealed no further gas in the liver.

Conclusions

The placement of a femoral venous catheter is a risk factor for gas formation in liver veins. No further treatment is needed in cases with stable liver function. To rule out serious pathologies, diagnostic findings (e.g., ultrasound, CT), clinical history and underlying diseases need to be analyzed carefully after the detection of intrahepatic gas formation. With contrast-enhanced CT, the localization of the gas and its potential causes might be detectable.

Transoral Endoscopic Thyroidectomy: Review of 81 Cases in a Single Institute

OBJECTIVE

To evaluate the clinical efficacy and safety of transoral endoscopic thyroidectomy (TOET).

MATERIALS AND METHODS

A total of 81 patients with thyroid nodules underwent TOET in our department from November 2011 to September 2015. The surgical outcomes, cosmetic results, and complications were evaluated.

RESULTS

Seventy-nine patients were performed TOET successfully, and 2 cases were transferred to open thyroidectomy due to intraoperative CO₂ embolism. The average operation time was 89.0 ± 38.6 minutes, and intraoperative blood loss was 29.3 ± 27.6 mL. Two cases experienced transient perioral numbness, and 2 cases experienced transient opening mouth pain. Two cases had transient increased saliva when swallowing. Transient anterior cervical region discomfort was found in 3 cases, and postoperative anterior cervical region infection was found in 4 cases. Other complications were not observed in any case. The average postoperative length of stay was 4.77 ± 2.61 days, and the mean follow-up period was 39.1 ± 22.6 months. During the follow-up period, there were no long-term complications or recurrent patient, and all the patients were satisfied with the cosmetic effect.

CONCLUSIONS

TOET is a safe and effective procedure with a low incidence of complications and perfect cosmetic effect for patients with thyroid diseases.

Laparoscopic VS open hepatectomy for hepatolithiasis: An updated systematic review and meta-analysis

AIM

To perform a meta-analysis on laparoscopic hepatectomy VS conventional liver resection for treating hepatolithiasis.

METHODS

We conducted a systematic literature search on PubMed, Embase, Web of Science and Cochrane Library, and undertook a meta-analysis to compare the efficacy and safety of laparoscopic hepatectomy VS conventional open liver resection for local hepatolithiasis in the left or right lobe. Intraoperative and postoperative outcomes (time, estimated blood loss, blood transfusion rate, postoperative intestinal function recovery time, length of hospital stay, postoperative complication rate, initial residual stone, final residual stone and stone recurrence) were analyzed systematically.

RESULTS

A comprehensive literature search retrieved 16 publications with a total of 1329 cases. Meta-analysis of these studies showed that the laparoscopic approach for hepatolithiasis was associated with significantly less intraoperative estimated blood loss [weighted mean difference (WMD): 61.56, 95% confidence interval (CI): 14.91-108.20, P = 0.01], lower blood transfusion rate [odds ratio (OR): 0.41, 95%CI: 0.22-0.79, P = 0.008], shorter intestinal function recovery time (WMD: 0.98, 95%CI: 0.47-1.48, P = 0.01), lower total postoperative complication rate (OR: 0.52, 95%CI: 0.39-0.70, P < 0.0001) and shorter stay in hospital (WMD: 3.32, 95%CI: 2.32-4.32, P < 0.00001). In addition, our results showed no significant differences between the two groups in operative time (WMD: 21.49, 95%CI: 0.27-43.24, P = 0.05), residual stones (OR: 0.79, 95%CI: 0.50-1.25, P = 0.31) and stone recurrence (OR: 0.34, 95%CI: 0.11-1.08, P = 0.07). Furthermore, with subgroups analysis, our results proved that the laparoscopic approach for hepatolithiasis in the left lateral lobe and left side could achieve satisfactory therapeutic effects.

CONCLUSION

The laparoscopic approach is safe and effective, with less intraoperative estimated blood loss, fewer postoperative complications, reduced length of hospital stay and shorter intestinal function recovery time than with conventional approaches.

Modified liver hanging maneuver focusing on outflow control in pure laparoscopic left-sided hepatectomy

BACKGROUND

Outflow control during laparoscopic liver resection necessitates the use of technically demanding procedures since the hepatic veins are fragile and vulnerable to damage during parenchymal transection. The liver hanging maneuver reduces venous backflow bleeding during deep parenchymal transection. The present report describes surgical outcomes and a technique to achieve outflow control during application of the modified liver hanging maneuver in patients undergoing laparoscopic left-sided hepatectomy.

METHODS

A retrospective review was performed of clinical data from 29 patients who underwent laparoscopic left-sided hepatectomy using the modified liver hanging maneuver between February 2013 and March 2017. For this hanging technique, the upper end of the hanging tape was placed on the lateral aspect of the left hepatic vein. The tape was then aligned with the ligamentum venosum. The position of the lower end of the hanging tape was determined according to left-sided hepatectomy type. The hanging tape gradually encircled either the left hepatic vein or the common trunk of the left hepatic vein and middle hepatic vein.

RESULTS

The surgical procedures comprised: left lateral sectionectomy (n = 10); left hepatectomy (n = 17); and extended left hepatectomy including the middle hepatic vein (n = 2). Median operative time was 210 min (range 90-350 min). Median intraoperative blood loss was 200 ml (range 60-600 ml). Two intraoperative major hepatic vein injuries occurred during left hepatectomy. Neither patient developed massive bleeding or air embolism. Postoperative major complications occurred in one patient (3.4%). Median postoperative hospital stay was 7 days (range 4-15 days). No postoperative mortality occurred.

CONCLUSIONS

The present modified liver hanging maneuver is a safe and effective method of outflow control during laparoscopic left-sided hepatectomy.

Different techniques for harvesting grafts for living donor liver transplantation: A systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis on minimally vs conventional invasive techniques for harvesting grafts for living donor liver transplantation.

METHODS

PubMed, Web of Science, EMBASE, and the Cochrane Library were searched comprehensively for studies comparing MILDH with conventional living donor hepatectomy (CLDH). Intraoperative and postoperative outcomes (operative time, estimated blood loss, postoperative liver function, length of hospital stay, analgesia use, complications, and survival rate) were analyzed in donors and recipients. Articles were included if they: (1) compared the outcomes of MILDH and CLDH; and (2) reported at least some of the above outcomes.

RESULTS

Of 937 articles identified, 13, containing 1592 patients, met our inclusion criteria and were included in the meta-analysis. For donors, operative time [weighted mean difference (WMD) = 20.68, 95%CI: -6.25-47.60, P = 0.13] and blood loss (WMD = -32.61, 95%CI: -80.44-5.21, P = 0.18) were comparable in the two groups. In contrast, analgesia use (WMD = -7.79, 95%CI: -14.06-1.87, P = 0.01), postoperative complications [odds ratio (OR) = 0.62, 95%CI: 0.44-0.89, P = 0.009], and length of hospital stay (WMD): -1.25, 95%CI: -2.35-0.14, P = 0.03) significantly favored MILDH. No differences were observed in recipient outcomes, including postoperative complications (OR = 0.93, 95%CI: 0.66-1.31, P = 0.68) and survival rate (HR = 0.96, 95%CI: 0.27-3.47, P = 0.95). Funnel plot and statistical methods showed a low probability of publication bias.

CONCLUSION

MILDH is safe, effective, and feasible for living donor liver resection with fewer donor postoperative complications, reduced length of hospital stay and analgesia requirement than CLDH.

Anesthetic and operative considerations for laparoscopic liver resection

We enumerate the broad range of anesthetic considerations that affect the outcome of patients undergoing laparoscopic liver resection. Key elements for excellent outcomes after laparoscopic liver resection are careful patient selection and risk stratification, appropriate monitoring, techniques to reduce blood loss and transfusion, and active recovery management. Although some of these key elements are the same for open liver operation, there are specific anesthetic considerations of which both the surgical and anesthesia teams must be aware to achieve optimal patient outcomes after laparoscopic liver resection. While unique advantages of laparoscopic liver resection typically include decreased intraoperative bleeding, transfusion requirements, and a lower incidence of postoperative ascites, specific challenges include management of the complicated interplay between low-volume anesthesia and increased intraabdominal pressure due to pneumoperitoneum, with additional considerations regarding circulatory support to treat acute blood loss with need for emergent conversion in some cases. This article will address in detail the preoperative, intraoperative, and postoperative anesthetic considerations for patients undergoing laparoscopic liver resection that both the surgical and anesthesia team should be aware of to optimize outcomes.

Comparison between minimally invasive and open living donor hepatectomy: A systematic review and meta-analysis

Living donor liver transplantation is a valid alternative to deceased donor liver transplantation, and its safety and feasibility have been well determined. Minimally invasive living donor hepatectomy (MILDH) has taken some time to be accepted because of inherent technical difficulties and the highly demanding surgical skills needed to perform the procedure, and its role is still being debated. Because of the lack of data, a systematic review and meta-analysis comparing MILDH and open living donor hepatectomy (OLDH) was performed. A systematic literature search was performed with PubMed, Embase, Scopus, and Cochrane Library Central. Treatment outcomes, including blood loss, operative time, hospital stay, analgesia use, donor-recipient morbidity and mortality, and donor procedure costs, were analyzed. There were 573 articles, and a total of 11, dated between 2006 and 2014, fulfilled the selection criteria and were, therefore, included. These 11 studies included a total of 608 adult patients. Blood loss [mean difference (MD) = -46.35; 95% confidence interval (CI) = -94.04-1.34; P = 0.06] and operative times [MD = 19.65; 95% CI = -4.28-43.57; P = 0.11] were comparable between the groups, whereas hospital stays (MD = -1.56; 95% CI = -2.63 to -0.49; P = 0.004), analgesia use (MD = -0.54; 95% CI = -1.04 to -0.03; P = 0.04), donor morbidity rates [odds ratio (OR) = 0.62; 95% CI = 0.40-0.98; P = 0.04], and wound-related complications (OR = 0.41; 95% CI = 0.17-0.97; P = 0.04) were significantly reduced in MILDH. MILDH for right liver procurement was associated with a significantly reduced hospital stay (OR = -0.92; 95% CI = 0.17-0.97; P = 0.04). In conclusion, MILDH is associated with intraoperative results that are comparable to results for OLDH and with surgical outcomes that are no worse than those for the open procedure.

Risk factors and consequences of conversion in laparoscopic major liver resection

BACKGROUND

Although recent reports have suggested potential benefits of the laparoscopic approach in patients requiring major hepatectomy, it remains unclear whether conversion to open surgery could offset these advantages. This study aimed to determine the risk factors for and postoperative consequences of conversion in patients undergoing laparoscopic major hepatectomy (LMH).

METHODS

Data for all patients undergoing LMH between 2000 and 2013 at two tertiary referral centres were reviewed retrospectively. Risk factors for conversion were determined using multivariable analysis. After propensity score matching, the outcomes of patients who underwent conversion were compared with those of matched patients undergoing laparoscopic hepatectomy who did not have conversion, operated on at the same centres, and also with matched patients operated on at another tertiary centre during the same period by an open laparotomy approach.

RESULTS

Conversion was needed in 30 (13·5 per cent) of the 223 patients undergoing LMH. The most frequent reasons for conversion were bleeding and failure to progress, in 14 (47 per cent) and nine (30 per cent) patients respectively. On multivariable analysis, risk factors for conversion were patient age above 75 years (hazard ratio (HR) 7·72, 95 per cent c.i. 1·67 to 35·70; P = 0·009), diabetes (HR 4·51, 1·16 to 17·57; P = 0·030), body mass index (BMI) above 28 kg/m(2) (HR 6·41, 1·56 to 26·37; P = 0·010), tumour diameter greater than 10 cm (HR 8·91, 1·57 to 50·79; P = 0·014) and biliary reconstruction (HR 13·99, 1·82 to 238·13; P = 0·048). After propensity score matching, the complication rate in patients who had conversion was higher than in patients who did not (75 versus 47·3 per cent respectively; P = 0·038), but was not significantly different from the rate in patients treated by planned laparotomy (79 versus 67·9 per cent respectively; P = 0·438).

CONCLUSION

Conversion during LMH should be anticipated in patients with raised BMI, large lesions and biliary reconstruction. Conversion does not lead to increased morbidity compared with planned laparotomy.

High-frequency jet ventilation shortened the duration of gas embolization during laparoscopic liver resection in a porcine model

BACKGROUND

Positive pressure mechanical ventilation causes rhythmic changes in thoracic pressure and central blood flow. If entrainment occurs, it could be easier for carbon dioxide to enter through a wounded vein during laparoscopic liver lobe resection (LLR). High-frequency jet ventilation (HFJV) is a ventilating method that does not cause pronounced pressure or blood flow changes. This study aimed to investigate whether HFJV could influence the frequency, severity, or duration of gas embolism (GE) during LLR.

METHODS

Twenty-four anaesthetized piglets underwent lobe resection and were randomly assigned to either normal frequency ventilation (NFV) or HFJV (n=12 per group). During resection, a standardized injury to the left hepatic vein was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored. Online blood gas monitoring and transoesophageal echocardiography were used. GE occurrence and severity were graded as 0 (none), 1 (minor), or 2 (major), depending on the echocardiography results.

RESULTS

GE duration was shorter in the HFJV group (P=0.008). However, no differences were found between the two groups in the frequency or severity of embolism. Incidence of Grade 2 embolism was less than that found in previous studies and physiological responses to embolism were variable.

CONCLUSION

HFJV shortened the mean duration of GE during LLR and was a feasible ventilation method during the procedure. Individual physiological responses to GE were unpredictable.

Effects of different pressure levels of CO2 pneumoperitoneum on liver regeneration after liver resection in a rat model

BACKGROUND

A recent study demonstrated that high pressure of carbon dioxide (CO2) pneumoperitoneum before liver resection impairs postoperative liver regeneration. This study was aimed to investigate effects of varying insufflation pressures of CO2 pneumoperitoneum on liver regeneration using a rat model.

METHODS

180 male Wistar rats were randomly divided into three groups: control group (without preoperative pneumoperitoneum), low-pressure group (with preoperative pneumoperitoneum at 5 mmHg), and high-pressure group (with preoperative pneumoperitoneum at 10 mmHg). After pneumoperitoneum, all rats were subjected to 70% partial hepatic resection and then euthanized at 0 min, 12 h, and on postoperative days (PODs) 1, 2, 4, and 7. Following outcome parameters were used: liver regeneration (liver regeneration rate, mitotic count, Ki-67 labeling index), hepatocellular damage (serum aminotransferases), oxidative stress [serum malondialdehyde (MDA)], interleukin-6 (IL-6), and hepatocyte growth factor (HGF) expression in the liver tissue.

RESULTS

No significant differences were observed for all parameters between control and low-pressure groups. The liver regeneration rate and mitotic count were significantly decreased in the high-pressure group than in control and low-pressure groups on PODs 2 and 4. Postoperative hepatocellular damage was significantly greater in the high-pressure group on PODs 1, 2, 4, and 7 compared with control and/or low-pressure groups. Serum MDA levels were significantly higher in the high-pressure group on PODs 1 and 2, and serum IL-6 levels were significantly higher in the high-pressure group at 12 h and on POD 1, compared with control and/or low-pressure groups. The HGF tissue expression was significantly lower in the high-pressure group at 12 h and on PODs 1 and 4, compared with that in control and/or low-pressure groups.

CONCLUSIONS

High-pressure pneumoperitoneum before 70% liver resection impairs postoperative liver regeneration, but low-pressure pneumoperitoneum has no adverse effects. This study suggests that following laparoscopic liver resection using appropriate pneumoperitoneum pressure, no impairment of liver regeneration occurs.

Risk factors and management of conversions to an open approach in laparoscopic liver resection: analysis of 265 consecutive cases

BACKGROUND

As a consequence of continuous technical developments in liver surgery, laparoscopic liver resection (LLR) is increasingly performed worldwide.

METHODS

Between January 2004 and December 2011, 265 LLR were performed in 242 patients for various diseases. The experience of LLR is reported focusing on risk factors of conversion and their management.

RESULTS

The overall conversion rate was 17/265 (6.4%), equally distributed over the period of the study. Statistically significant factors for conversion were found to be LLR of the postero-superior (P-S) segments (SI, SIVa; SVII; SVIII) (12.7% converted versus 2.5% non-converted groups, P = 0.01) and a major compared with a minor hepatectomy (15.2% vs. 4.6%, P = 0.02 respectively). A R0 resection was achieved in 93.2% of cases. According to Dindo's classification, complications were recorded as grade I (n = 20); grade II (6); grade III (11) and grade IV(1) events (total morbidity rate of 14%). Univariate analysis identified a major hepatectomy and resection involving P-S segments as prognostic factors for conversion whereas multivariate analysis identified the latter as an independent risk factor [P = 0.003, odds ratio (OR) = 5.9, 95% confidence interval (CI) = 1.8-18.8].

CONCLUSIONS

LLR can be safely performed with low overall morbidity. According to this experience and irrespective of the learning curve, resections of P-S segments were identified as an independent risk factor for conversion in LLR.

Suspected cerebral arterial gas embolism during a laparoscopic Nissen fundoplication

We present the first case report known to us of a suspected cerebral arterial gas embolism (CAGE) leading to transient left-sided hemiparesis after a laparoscopic Nissen fundoplication. During the operation there was no evidence of hemodynamic compromise and the end-tidal carbon dioxide level and oxygen saturation had been within normal limits. Radiological studies and transesophageal echocardiography showed no abnormalities. We conclude that CAGE can occur during uncomplicated laparoscopic surgery even in the absence of demonstrable intracardiac shunts.

Gas embolism in laparoscopic hepatectomy: what is the optimal pneumoperitoneal pressure for laparoscopic major hepatectomy?

Laparoscopic hepatectomy (LH) has become popular as a surgical treatment for liver diseases, and numerous recent studies indicate that it is safe and has advantages in selected patients. Because of the magnified view offered by the laparoscope under pneumoperitoneal pressure, LH results in less bleeding than open laparotomy. However, gas embolism is an important concern that has been discussed in the literature, and experimental studies have shown that LH is associated with a high incidence of gas embolism. Major hepatectomies are done laparoscopically in some centers, even though the risk of gas embolism is believed to be higher than for minor hepatectomy due to the wide transection plane with dissection of major hepatic veins and long operative time. At many high-volume centers, LH is performed at a pneumoperitoneal pressure less than 12 mmHg, and reports indicate that the rate of clinically severe gas embolism is low. However, more studies will be necessary to elucidate the optimal pneumoperitoneal pressure and the incidence of gas embolism during LH.

Laparoscopic major hepatectomy: a systematic literature review and comparison of 3 techniques

OBJECTIVE

This review assesses the current status of laparoscopic liver resection.

BACKGROUND

The trend in laparoscopic liver resection has been moving from limited resections toward major hepatectomy. The surgical techniques for laparoscopic major hepatectomy include pure laparoscopic, hand-assisted laparoscopic, and laparoscopy-assisted methods. We performed a literature search and systematic review to assess the current status of laparoscopic major hepatectomy.

METHODS

Our literature review was conducted in Medline using the keywords "laparoscopy" or "laparoscopic" combined with "liver resection" or "hepatectomy." Articles written in English containing more than 10 cases of laparoscopic major hepatectomy were selected.

RESULTS AND CONCLUSIONS

Twenty-nine articles were selected for this review. The laparoscopic major hepatectomies achieved similar patient and economic outcomes compared with open liver resections in selected (noncirrhotic) patients. Surgeon experience with the techniques affected the results; thus, a learning period is mandatory. Of these 3 techniques, the pure laparoscopic method is suitable for experienced surgeons to achieve better cosmetic outcomes, whereas the hand-assisted laparoscopic method was associated with better perioperative outcomes; the laparoscopy-assisted method is used by surgeons for unique resections such as resection of cirrhotic livers, laparoscopic resection of tumors in unfavorable locations, and living donor hepatectomies. In addition, the laparoscopic major hepatectomy-specific, long-term oncologic outcomes remain to be addressed in future publications.

Laparoscopy Decreases the Laparotomy Rate in Hemodynamically Stable Patients With Blunt Abdominal Trauma

Background. This study evaluated the use of laparoscopy in hemodynamically stable patients with blunt abdominal trauma. Methods. We retrospectively reviewed the medical records of hemodynamically stable blunt abdominal trauma patients. Patients admitted from July 1, 2003, to June 30, 2006 (prior to the adoption of laparoscopy for patients with blunt abdominal trauma) were categorized as group A. Patients admitted from July 1, 2007, to June 30, 2010, when laparoscopy was included in the algorithm for the management of blunt abdominal trauma, were categorized as group B. Results. There were 47 patients in group A and 57 patients in group B. There were no significant differences in demographic characteristics, injury severity score, and injuries requiring surgical intervention between the groups (all, P > .05). Patients in group B had a shorter hospital stay (11 days vs 21 days, P < .001) and shorter ICU stay (0 [0, 1] days vs 0 [0, 9] days, P = .029). In group A, 6 of 47 patients (12.8%) underwent a nontherapeutic laparotomy. In contrast, 9 of 57 patients (15.8%) in group B avoided a nontherapeutic laparotomy because no significant intra-abdominal findings warranting an intervention were disclosed by laparoscopy. The incidence of laparotomy for patients with significant injuries in group B was lower than in group A (4.2% vs 100.0%; P < .001). There was no difference in the complication rate between the groups. Conclusions. Laparoscopy is feasible and safe for the diagnosis and treatment of hemodynamically stable patients with blunt abdominal trauma and can reduce the laparotomy rate.