CO2 embolism can complicate transanal total mesorectal excision

Multicenter phase II trial of transanal total mesorectal excision for rectal cancer: preliminary results

BACKGROUND

Transanal TME (taTME) combines abdominal and transanal dissection to facilitate sphincter preservation in patients with low rectal tumors. Few phase II/III trials report long-term oncologic and functional results. We report early results from a North American prospective multicenter phase II trial of taTME (NCT03144765).

METHODS

100 patients with stage I-III rectal adenocarcinoma located ≤ 10 cm from the anal verge (AV) were enrolled across 11 centers. Primary and secondary endpoints were TME quality, pathologic outcomes, 30-day and 90-day outcomes, and stoma closure rate. Univariable regression analysis was performed to assess risk factors for incomplete TME and anastomotic complications.

RESULTS

Between September 2017 and April 2022, 70 males and 30 females with median age of 58 (IQR 49-62) years and BMI 27.8 (IQR 23.9-31.8) kg/m2 underwent 2-team taTME for tumors located a median 5.8 (IQR 4.5-7.0) cm from the AV. Neoadjuvant radiotherapy was completed in 69%. Intersphincteric resection was performed in 36% and all patients were diverted. Intraoperative complications occurred in 8% including 3 organ injuries, 2 abdominal and 1 transanal conversion. The 30-day and 90-day morbidity rates were 49% (Clavien-Dindo (CD) ≥ 3 in 28.6%) and 56% (CD ≥ 3 in 30.4% including 1 mortality), respectively. Anastomotic complications were reported in 18% including 10% diagnosed within 30 days. Higher anastomotic risk was noted among males (p = 0.05). At a median follow-up of 5 (IQR 3.1-7.4) months, 98% of stomas were closed. TME grade was complete or near complete in 90%, with positive margins in 2 cases (3%). Risk factors for incomplete TME were ASA ≥ 3 (p = 0.01), increased time between NRT and surgery (p = 0.03), and higher operative blood loss (p = 0.003).

CONCLUSION

When performed at expert centers, 2-team taTME in patients with low rectal tumors is safe with low conversion rates and high stoma closure rate. Mid-term results will further evaluate oncologic and functional outcomes.

Transanal Total Mesorectal Excision for Rectal Cancer

Transanal total mesorectal excision (taTME) is a technique where rectal dissection is begun transanally in a "bottom-up" fashion. This technique facilitates dissection of the most distal part of the rectum and allows the establishment of the distal margin for rectal cancer. TaTME has proven its utility in facilitating low rectal dissection with significantly lower conversion rates and acceptable perioperative, oncological, and functional outcomes. However, taTME remains a challenging technique to learn and adopt. This article describes the technique, indications, and outcomes of taTME in rectal cancer during the last decade.

The global status and hotspots of research in the field of trans-oral endoscopic thyroidectomy (TOET) from 2008 to 2022

Purpose

In this study, the aim was to comprehensively analyze the current status, hotspots, and trends of trans-oral endoscopic thyroidectomy (TOET) through bibliometric analysis and by presenting the field atlas.

Methods

Web of Science Core Collection database was adopted to screen studies regarding TOET published between January 1, 2008 and August 1, 2022. The evaluation covered the criteria total number of studies, keywords, and contributions from countries/regions, institutions, journals, and authors.

Results

A total of 229 studies were covered. SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES is the largest publication in the field of TOET. The three countries that contributed the most studies were Korea, China, and the USA. The most frequently occurring core keywords in the field of TOET are vestibular approach, outcomes, experience, safety, robotic thyroidectomy, scar, video-assisted thyroidectomy and quality-of-life. The seven clusters were generated in this study: intraoperative monitoring of the laryngeal return nerve (# 0), learning curve (# 1), postoperative quality of life (# 2), central lymph node dissection and safety (# 3), complications (# 4), minimally invasive surgery (# 5), and robotic surgery (# 6).

Conclusion

The main research topics in the field of TOET place focuses on learning curves, laryngeal nerve monitoring, carbon dioxide gas bolus, chin nerve injury, surgical complications, and surgical safety. In the future, more academics will focus on the safety of the procedure and reducing complications..

Detection of carbon dioxide embolism by transesophageal echocardiography during transanal/perineal endoscopic surgery: a pilot study

The transanal/perineal (ta/tp) endoscopic approach has been widely used for anorectal surgery in recent years, but carbon dioxide embolism is a possible lethal complication. The frequency of this complication in this approach is not known. In this study, we investigated the frequency of intraoperative (including occult) carbon dioxide embolism using transesophageal echocardiography. Patients who underwent surgery via the ta/tp approach and consented to participate were included. Intraoperative transesophageal echocardiography was used to observe the right ventricular system in a four-chamber view. Changes in end-tidal carbon dioxide (EtCO₂), oxygen saturation (SpO₂), and blood pressure were taken from anesthesia records. Median maximum insufflation pressure during the ta/tp approach was 13.5 (12-18) mmHg. One patient (4.8%) was observed to have a bubble in the right atrium on intraoperative transesophageal echocardiography, with a decrease in EtCO₂ from 39 to 35 mmHg but no obvious change in SpO₂ or blood pressure. By lowering the insufflation pressure from 15 to 10 mmHg and controlling bleeding from the veins around the prostate, the gas rapidly disappeared and the operation could be continued. Among all patients, the range of variation in intraoperative EtCO₂ was 5-22 mmHg, and an intraoperative decrease in EtCO₂ of > 3 mmHg within 5 min was observed in 19 patients (median 5 mmHg in 1-10 times).Clinicians should be aware of carbon dioxide embolism as a rare but potentially lethal complication of anorectal surgery, especially when using the ta/tp approach.

Carbon dioxide embolism during transanal total mesorectal excision: A hint of prevention from a case report

Transanal total mesorectal excision is a relatively new approach for treating lower rectal cancer. Carbon dioxide embolism is a critical complication of this procedure. We report the case of a 69-year-old man with lower rectal cancer who underwent transanal total mesorectal excision followed by laparoscopic low anterior resection. He had a sudden intraoperative carbon dioxide embolism during the transanal mesorectal excision. During the ventral dissection of the rectum, end-tidal carbon dioxide and blood oxygen saturation suddenly decreased. We stopped the insufflation of carbon dioxide and suspended the procedure. There was no circulatory collapse, and the vital signs gradually recovered; therefore, we resumed the surgery approximately 30 minutes later and completed it without additional complications. Upon reviewing the video, we found a small injured vein that would aspirate carbon dioxide. These findings suggested that careful hemostasis is essential to prevent carbon dioxide embolus during transanal total mesorectal excision.

Carbon Dioxide Embolism During Transanal Total Mesorectal Excision: Case Report and Literature Review

The actual incidence of carbon dioxide embolism during transanal total mesorectal excision (taTME) is unknown, but the reported incidence in the existing literature is reassuring. However, the incidence of CO2 embolism, which can be life-threatening, is severely underestimated. By reviewing the available data on carbon dioxide embolism during taTME and synthesizing other reports on CO2 embolism in laparoscopic procedures, we provide the first comprehensive account of the etiology, pathophysiology, and recommend tools to monitor carbon dioxide embolism during taTME. Additionally, we provide guidance and recommendations on preventive and therapeutic measures to minimize the adverse consequences of this potentially severe complication, knowledge about which we hope will improve patients' safety.

Limitations and Concerns with Transanal Total Mesorectal Excision for Rectal Cancer

Transanal total mesorectal excision (TaTME) was developed to overcome the technical challenges of a minimally invasive (ultra-) low anterior resection. This new technique has recently come under careful scrutiny as technical pitfalls were reported, in specific relation to the transanal approach. Patients are at risk for urologic lesions. Moreover, carbon dioxide embolism is a rare but potentially life-threatening complication. The benefit of TaTME from an oncological point of view has neither been clarified. Hypothetically, better visualization of the lower rectum could lead to better dissection and total mesorectal excision (TME) specimens, resulting in better oncologic results. Up until now, retrospective multicenter reports seem to show that short-term oncologic results are not inferior after TaTME as compared with after laparoscopic TME. Alarming reports have however been published from Norway suggesting a high incidence and particular multifocal pattern of early local recurrence. In this article, a balanced overview is given of the most important technical pitfalls and oncological concerns arising with this new procedure.

Needle insufflation into the liver as a cause of massive gas embolus and CVA

Laparoscopy is being applied more frequently and in broader applications. Complications of this technique are infrequent, and rare among them are gas emboli due to insufflation. This paper describes a 65-year-old obese female presenting for elective laparoscopic cholecystectomy who suffered a cerebral vascular accident after Veress needle insertion into undiagnosed severe fatty liver led to a massive gas embolus. Our patient experienced immediate cardiac compromise and acute monoparesis. Intra-operative transesophageal echocardiogram revealed copious air in the right atria and ventricle. A needle track within the liver was visible on a post-operative computerized tomography scan. The patient made a full recovery, but this acts as a reminder to be vigilant for potential complications of laparoscopy and highlights challenges of laparoscopic entry in the severely obese.

Total Transperineal Laparoscopic Proctectomy for the Treatment of Crohn's Proctitis

INTRODUCTION

Completion proctectomy is traditionally performed using a combination of abdominal and perineal approaches. Access to and exposure of the pelvis through the abdominal cavity can be limited in patients with prior surgery or inflammatory conditions. We describe a novel technique for a total transperineal approach for proctectomy for Crohn's proctitis, avoiding technical challenges, risks, and recovery associated with abdominal surgery.

TECHNIQUE

We utilized the skills and expertise acquired from our experience with transanal total mesorectal excision to perform a total transperineal laparoscopic proctectomy in a male patient with medically refractory proctitis. He previously underwent an anterior resection, drainage of a chronic presacral abscess, omental pedicle flap transposition to the pelvis, and end colostomy for severe Crohn's colitis. The total transperineal laparoscopic proctectomy approach avoids the need for abdominal access, including the risks associated with abdominal entry, adhesiolysis, pelvic access and visualization, and wound-related issues. Following an initial intersphincteric perineal dissection, the GelPOINT Path minimal access platform is utilized to perform a total transperineal proctectomy.

RESULTS

The patient recovered uneventfully and was discharged to home 2 days after surgery. At 1-month postoperative follow-up, the patient is recovering well with complete healing of the perineal wound.

CONCLUSION

We demonstrate the feasibility, safety, and technical steps of a minimally invasive completion proctectomy for fistulizing Crohn's proctitis by using a total transperineal approach. This approach allowed us to utilize direct, inline, high-definition visualization to access and safely operate in the distal aspects of a narrow, scarred, and fibrotic pelvis while avoiding the need for any abdominal access. Advanced experience with redo pelvic and minimally invasive transanal surgery is critical. See Video at http://links.lww.com/DCR/B664.

Options for Low Rectal Cancer: Robotic Total Mesorectal Excision

Low rectal cancers (LRCs) may offer a difficult technical challenge even to experienced colorectal surgeons. Although laparoscopic surgery offers a superior exposure of the pelvis when compared with open approach, its role in rectal cancer surgery has been controversial. Robotic platforms are well suited for difficult pelvic surgery due to its three-dimensional visualization, degree of articulation of instruments, precise movements, and better ergonomics. The robot may be suitable especially in the anatomically narrow pelvis such as in male and obese patients. Meticulous dissection in critical steps, such as splenic flexure takedown, nerve-sparing mesorectal excision, and distal margin clearance, are potential technical advantages. In addition, robotic rectal resections are associated with lower conversion rates to open surgery, less blood loss, and shorter learning curve with similar short-term quality of life outcomes, similar rates of postoperative complications, and equivalent short-term surrogate outcomes compared with conventional laparoscopy. Robotic surgery approach, if used correctly, can enhance the skills and the capabilities of the well-trained surgeon during minimally invasive procedures for LRC.

The learning curve of transanal total mesorectal excision for rectal cancer is associated with local recurrence: results from a multicentre external audit

AIM

Transanal total mesorectal excision (TaTME) has been suggested as a potential solution for the resection of challenging mid and low rectal cancer. This relatively complex procedure has been implemented in many centres over the last years, despite the absence of long-term safety data. Recently, concern has arisen because of an increase in local recurrence in the implementation phase. The aim of this study was to assess the correlation between accumulated experience and local recurrences.

METHOD

An independent clinical researcher performed an external audit of consecutive series of all TaTME procedures in six centres in the Netherlands. Kaplan-Meier estimated local recurrence rates were calculated and multivariate Cox proportional hazards regression analysis performed to assess risk factors for local recurrence. Primary outcome was the local recurrence rate in the initial implementation (cases 1-10), continued adoption (cases 11-40) and prolonged experience (case 41 onward).

RESULTS

Six hundred and twenty-four consecutive patients underwent TaTME for rectal cancer with a median follow-up of 27 months (range 1-82 months). The estimated 2- and 3-year local recurrence rates were 4.6% and 6.6%, respectively. Cox proportional hazards regression revealed procedural experience to be an independent factor in multivariate analysis next to advanced stage (ycMRF+, pT3-4, pN+) and pelvic sepsis. Corrected analysis projected the 3-year local recurrence rates to be 9.7%, 3.3% and 3.5% for the implementation, continued adoption and prolonged experience cohorts, respectively.

CONCLUSION

This multicentre study shows a high local recurrence rate (12.5%) after implementation of TaTME which lowers to an acceptable rate (3.4%) when experience increases. Therefore, intensified proctoring and further precautions must be implemented to reduce the unacceptably high risk of local recurrence at units starting this technique.

Venous Gas Embolism During Radical Robotic Prostatectomy: A Case Report and Evidence-Based Management Algorithm

Robotic-assisted radical prostatectomy (RARP) has gained rapid popularity in the last two decades after early reports of excellent survival rates, quick learning curves, and minimal invasion or tissue damage. Given the anatomical location of surgical prostatectomies and the utilization of intra-abdominal gas during laparoscopy, there is a risk of developing venous air embolism (VAE). We present a case of a 62-year-old male with hypothyroidism and benign prostatic hyperplasia who underwent robotic suprapubic prostatectomy under general anesthesia. One hour after incision the ETCO2 suddenly dropped (40 mmHg to 25 mmHg) as did the SpO2 (98% to 90%). There were no other vital sign changes, nor was there significant blood loss. The surgical team was notified, which prompted the surgeon to inform us that he had just been dissecting around the pelvic venous plexus. At this point, with the clinical suspicion of VAE, abdominal insufflation pressure was lowered, and inspired oxygen was increased to 100%. After 10 minutes, SpO2 and ETCO2 normalized. A debrief and literature review inspired us to develop a laparoscopic-specific VAE management algorithm, with attention to robotic-case management issues. To the best of our knowledge, this is a rare case report describing a clinical VAE during RARP.

Transanal Minimally Invasive Surgery: An Effective Approach for Patients Who Require Redo Pelvic Surgery for Anastomotic Failure

BACKGROUND

Anastomotic leaks cause significant patient morbidity that may require redo pelvic surgery. Transanal minimally invasive surgery facilitates direct access to the pelvis with increased visualization and maneuverability for technically difficult redo surgery.

OBJECTIVE

This study aimed to assess the feasibility and outcomes of transanal minimally invasive surgery in redo proctectomy for anastomotic complications.

DESIGN

This was a retrospective cohort study.

SETTINGS

This study was conducted at a single tertiary-care institution.

PATIENTS

Consecutive patients undergoing transanal minimally invasive redo proctectomy were included.

INTERVENTIONS

Transanal minimally invasive redo proctectomy was performed.

MAIN OUTCOME MEASURES

The primary end point was intraoperative feasibility. The secondary end points were safety, perioperative morbidity, and symptom resolution.

RESULTS

Seven patients underwent redo proctectomy via transanal minimally invasive surgery for anastomotic defect (n = 6) or stricture (n = 1). Median time from initial to redo operation was 27 months (range, 13-67). Redo proctectomy included redo low anterior resection with coloanal anastomosis and diverting loop ileostomy (n = 4), completion proctectomy with end colostomy (n = 2), and pouch resection with end ileostomy (n = 1). Six patients had an open abdominal approach. There were no conversions for the anal approach. Median operative time was 6.4 hours (range, 4.0-7.1). All 4 planned redo coloanal anastomoses were successfully created. Hospital length of stay was a median of 8 days (interquartile range, 6-9). Intraoperative complications included 2 patients with carbon dioxide emboli, which resolved with supportive care; there was no adjacent organ injury. Three patients were readmitted within 30 days. There were no postoperative anastomotic leaks, and all 4 patients with diverted ileostomies underwent reversal at a median of 4 months (interquartile range, 4-6). All symptoms prompting redo surgery remain resolved at a median follow-up of 20 months.

LIMITATIONS

This study was limited by its small sample size and its single-institution focus.

CONCLUSION

For those with expertise in transanal surgery, transanal minimally invasive surgery is a safe and effective option for patients with anastomotic failure requiring redo proctectomy because it provides direct access to and visualization of the pelvis.

A case of carbon dioxide embolism during the transperineal approach in total pelvic exenteration for advanced anorectal cancer

The transanal and transperineal endoscopic approaches are useful advanced surgical options for removing rectal and anorectal cancers. Intraoperative carbon dioxide (CO₂ ) embolisms, however, have been increasingly reported as potentially fatal complications associated with surgery employing these approaches. We report our experience with a CO₂ embolism that was detected because of a sudden drop in end-tidal CO₂ with decreasing saturation of percutaneous arterial oxygen during total pelvic exenteration using the transperineal endoscopic approach under pneumopelvis/pneumoperitoneum. Transesophageal echocardiography confirmed that it was a CO₂ embolus. We reversed the pneumopelvis and pneumoperitoneum, which alleviated the cardiopulmonary problems, and the surgery then proceeded to achieve R0 resection. The patient was discharged without severe complications other than the CO₂ embolism.

Development and early outcomes of the national training initiative for transanal total mesorectal excision in the UK

AIM

Transanal total mesorectal excision (TaTME) has attracted substantial interest amongst colorectal surgeons but its technical challenges may underlie the early reports of visceral injuries and oncological concerns. The aim of this study was to report on the feasibility, development and the outcome of the national pilot training initiative for TaTME-UK.

METHODS

TaTME-UK was successfully launched in September 2017 in partnership with the healthcare industry and endorsed by the Association of Coloproctology of Great Britain and Ireland. This multi-modal training curriculum consisted of three phases: (i) set-up; (ii) selection of pilot sites; and (iii) formal proctorship programme. Bespoke Global Assessment Scoring (GAS) forms were designed and completed by both trainees and mentors. Data were collected on patient demographics, tumour characteristics and perioperative clinical and histological outcomes.

RESULTS

Twenty-four proctored cases were performed by 10 colorectal surgeons from five selected pilot sites. Median operative time was 331 ± 90 (195-610) min which was reduced to 283 ± 62 (195-340) min in the final case. Independent performance (GAS score of 5) was achieved for most operative steps by case 5. There was one conversion (4.2%), but no visceral injuries. Pathological data confirmed no bowel perforation and intact quality of the mesorectal TME specimens with clear distal margin in all cases and circumferential margins in 23/24 cases (96%).

CONCLUSION

This exploratory study demonstrates acceptable early outcomes in a small cohort suggesting that a competency-based multi-modal training programme for TaTME can be feasible and safe to implement at a national level.

International expert consensus guidance on indications, implementation and quality measures for transanal total mesorectal excision

AIM

To provide dynamic guidance from a rigorous and up-to-date consensus on the safe implementation and application of transanal total mesorectal excision (TaTME) from an international panel of expert surgeons and educationalists supported by 14 international surgical societies.

METHOD

An adapted Delphi method and focus group discussion approach was implemented for this consensus process, with expert advice from a guidelines methodologist. Statements were generated focusing on three main topics relating to the safe implementation of TaTME: (1) indications, (2) quality and outcome measures, (3) training and implementation of TaTME.

RESULTS

Five rounds of the Delphi consensus process were completed over a 13-month period. A total of 56 surgeons experienced in TaTME and surgical education participated in this project. By Delphi round four, 80.0% or greater agreement was reached for all statements except for two, which were further reviewed during a fifth round. More complex cases that are likely to benefit from TaTME were identified, with the recommendation that they should be referred to TaTME expert centres. The most agreed upon definition of expert centres is outlined.

CONCLUSION

We have provided a current framework of best practice related to implementation of TaTME. The statements are not indefinite and will continue to be 'dynamic' and updated as new evidence emerges.

Carbon dioxide embolism during transanal total mesorectal excision (TaTME): two case reports

Transanal total mesorectal excision (TaTME), a new approach for rectal cancers, requires transanal carbon dioxide (CO2) high-flow insufflation to create a workplace. Two patients scheduled for TaTME experienced CO2 embolism during the anterior mesorectal dissection in contact with the prostate. CO2 embolism resulted in a sudden drop of end-tidal CO2, preceded by a short increase in one patient, and in oxygen desaturation. Hemodynamic alterations were minor. We report these two cases and discuss the pathophysiology of CO2 embolism and risk factors that promote CO2 embolism during TaTME to warn anesthetists of this serious complication, often unexpected and misdiagnosed.