Anesthesia in per-oral endoscopic myotomy: A large tertiary care centre experience

Complications related to third space endoscopic procedures

Third space endoscopy (TSE) encompasses a breadth of procedures for the treatment of a variety of GI disorders. The widespread use of per-oral endoscopic myotomy (POEM) and its diversification to include extended indications and at locations other than the oesophagus has provided an insight into the potential complications encountered. The most common adverse events associated with POEM, the epitome of TSE procedures, include insufflation related injuries, bleeding, failure of mucosal barrier, infections, pain, blown out myotomy and gastroesophageal reflux disease. The purpose of this review is to highlight the pitfalls and to identify the risk factors that may lead to adverse events, and to recommend appropriate salvage interventions in the scope of the current evidence.

Invasive CO 2 monitoring with arterial line compared to end tidal CO 2 during peroral endoscopic myotomy

Background and study aims  Peroral endoscopic myotomy (POEM) has become a recognized treatment for achalasia. The technique requires CO 2 insufflation. It is estimated that the partial pressure of CO 2 (PaCO 2 ) is 2 to 5 mm Hg higher than the end tidal CO 2 (etCO 2 ), and etCO 2 is used as a surrogate for PaCO 2 because PaCO 2 requires an arterial line. However, no study has compared invasive and noninvasive CO 2 monitoring during POEM. Patients and methods  Seventy-one patients who underwent POEM were included in a prospective comparative study. PaCO 2 plus etCO 2 was measured in 32 patients (invasive group) and etCO 2 only in 39 matched patients (noninvasive group). Pearson correlation coefficient (PCC) and Spearman's Rho were used to calculate the correlation between PaCO 2 and ETCO 2 . Results  PaCO 2 and ETCO 2 were strongly correlated: PCC R value: 0.8787 P  ≤ 0.00001, Spearman's Rho R value: 0.8775, P  ≤ 0.00001. Within the invasive group, the average difference between PaCO 2 and ETCO 2 was 3.39 mm Hg (median 3, standard deviation 3.5), within the 2- to 5-mm Hg range. The average procedure time (scope in to scope out) was increased 17.7 minutes ( P  = 0.044) and anesthesia duration was 46.3 minutes. Adverse events (AEs) included three hematomas and one nerve injury in the invasive group and one pneumothorax in the noninvasive group. There were no differences in AE rates between the groups (13 % vs 3 % P  = 0.24). Conclusions  Universal PaCO 2 monitoring contributes to increased procedure and anesthesia times without any decrease in AEs in patients undergoing POEM. CO 2 monitoring with an arterial line should only be performed in patients with major cardiovascular comorbidities; in all other patients, ETCO 2 is an appropriate tool.

Per Oral Endoscopic Myotomy (POEM) for pediatric achalasia: Institutional experience and outcomes

BACKGROUND

The surgical treatment of achalasia by both laparoscopic and endoscopic approaches has been recognized as the definitive management in children. Despite reported low volumes in many centers, there has been an increasing worldwide experience with endoscopic approaches to pediatric achalasia. The aim of this study is to report our institutional experience with per oral endoscopic myotomy (POEM) as first-line or revisional therapy for achalasia.

METHODS

An IRB approved retrospective review of all patients who underwent operative procedures for achalasia, specifically with the POEM technique, from July 2015 to September 2021. Data including demographics, intra-operative details, pre and post operative Eckardt scores, complications, outcomes, and follow-up were obtained.

RESULTS

During the study period, a total of 43 children underwent 46 operations for achalasia including POEM and laparoscopic Heller myotomy (LHM). Operations included 37 POEMS (33 primary POEMS; 3 POEMS after failed LHM; and 1 POEM after failed POEM). Additionally, 9 LHM operations including, 4 primary LHM; 3 attempted POEMS converted to LHM; 1 attempted POEM after failed LHM converted to redo LHM; and 1 LHM after failed POEM. In the POEM group (n = 37), based on the high resolution esophageal manometry findings Chicago Classification types at diagnosis were as follows: 9 patients were type I (24.3%); 25 patients were type II (67.6%); 2 patients were type III (5.9%) and 1 patient was unknown type (2.7%). Sixteen children (43.2%) had prior endoscopic treatment of achalasia prior to POEM [Pneumatic Balloon Dilatation (PBD), and/or Botox injection (BTI)],), while prior operative intervention occurred in 4 patients (10.8%), 3 LHM and 1 POEM. Age at operation was 2-18 years (mean ± SD age: 11.6 ± 4.5 years). Weight at operation 11.8-100.7 kg (mean ± SD kg; 39 ± 19.9 kg). Range of baseline Eckardt score was 4-10 (mean ± SD: 6.73 ± 1.5). Operative time was 64-359 min (mean ± SD minutes: 138.1 ± 62.2 min). Intraoperative complications occurred in 16 patients (43.2%) but did not require reoperation during index admission including: 4 mucosotomy (11.8%); 9 pneumothoraces (24.3%); 2 pneumomediastinum (5.4%); 10 pneumoperitoneum (27%); 0 sub-mucosal tunnel bleeding (0%); 0 open conversion/death (0%). Post operative complications included: 5 recurrent dysphagia (13.5%); 0 esophageal leak (0%); 3 GERD (8.1%); 1 failed POEM (2.7%). Median length of stay was 2 days (mean ± SD days: 2.4 ± 0.9 day). Follow-up ranged from 1 to 74 months (median 15 months), mean follow-up 22.6 months ± 20 months. Post POEM Eckardt score was 0.6 ± 0.9. Five patients required a single PBD post POEM (13.5%) and 1 patient required a repeat myotomy (LHM) after POEM (2.7%) for a 16.2% reintervention rate. Subsequent normalization of Eckardt scores (≤ 3) and symptomatic relief was achieved in all patients (100%).

CONCLUSIONS

POEM as first-line therapy for pediatric achalasia, or as a secondary procedure after failed prior myotomy or POEM, in our experience is safe and effective. We have shown equivalent results to our own prior experience with LHM. Long-term follow-up will be performed to monitor for recurrent symptoms, adequate physical growth, and general development.

LEVEL OF EVIDENCE

II.

Anesthesia for Per-oral endoscopic myotomy (POEM) – not so poetic!

Peroral endoscopic myotomy (POEM) is a promising natural orifice transluminal endoscopic procedure for the treatment of esophageal motility disorders, with similar effectiveness as of Heller myotomy. It is performed under general anesthesia in endoscopy suite. Creation of submucosal tunnel in the esophageal wall is a key component. The continuous insufflation of CO₂ inadvertently tracks into surrounding tissues and leads to capno mediastinum, capno thorax, capno peritoneum, and subcutaneous emphysema. Thus, the challenges, for an anesthesiologist are not only providing remote location anesthesia, increased risk of aspiration during induction, but also early detection of these complications and specific emergency management. Though a therapeutic innovation, POEM remains an interdisciplinary challenge with no specific anesthesia care algorithms and evidence-based recommendations. The purpose of this review is to outline the anesthesia and periprocedural practices based on existing evidence.

Challenges in Anesthesia Management for Peroral Endoscopic Myotomy: A Retrospective Analysis

BACKGROUND

Peroral endoscopic myotomy (POEM) is used to treat achalasia with efficacy and reliability. However, during the procedure potential complications require attention in terms of anesthesia. This study aimed to investigate complications of the POEM procedure and its effects on arterial blood gas (ABG) parameters, peak airway pressures (PIP), hemodynamics, and postoperative analgesia requirements.

METHODS

Data from 220 patients who underwent POEM between 2014 and 2017 were retrospectively assessed. During the procedure, ABG samples, PIP, mean arterial pressure, and heart rate were recorded. The effects of the procedure and paracentesis on ABG, PIP, mean arterial pressure, heart rate, perioperative complications, and postoperative analgesia requirements were assessed.

RESULTS

Data from 220 POEM patients were analyzed. During the procedure, the mean PaCO2 was 48.27±6.34 mm Hg, which was significantly higher than the PaCO2 values before and after the procedure. The mean increase in maximum PIP was 5.90±3.49 cmH2O during the procedure. However, there was a significant decrease in PaCO2 and PIP values in cases with paracentesis compared with those without paracentesis. With regards to complications, subcutaneous emphysema (48, 21.8%), pneumoperitoneum requiring decompression (66, 30%), pneumothorax (1, 0.5%), aspiration pneumonia (1, 0.5%), and bronchospasm (5, 2.2%) were observed during the procedure. In the postoperative period, 58 patients (26%) had additional analgesia requirements because of visual analog scale values >3.

CONCLUSION

Periprocedural abdominal decompression with veress needle led to a reduction in arterial PaCO2 and PIP, and improved postoperative analgesia. Serious complications because of perioperative aspiration and CO2 insufflation were observed during the POEM procedure.

[Anesthesia in gastrointestinal endoscopy: peroral endoscopic myotomy]

Idiopathic achalasia is a motility disorder of the esophagus characterized by a dysfunction of the lower esophageal sphincter, which typically manifests as dysphagia. Peroral endoscopic myotomy (POEM) is an interventional endoscopic procedure for achalasia, which was introduced in 2010. Although results from randomized studies comparing short-term and long-term safety and efficacy are yet to be published, POEM is regarded to be less invasive than the standard treatment of achalasia (laparoscopic Heller myotomy). POEM is the first endoscopic procedure routinely performed with the patient under general anesthesia. During the preoperative assessment particular attention must be paid to the specific fasting intervals and the risk of aspiration during induction of anesthesia. For the purpose of temporary surgical access, the integrity of the esophageal wall is deliberately interrupted to create a long submucosal tunnel. As a result, unwanted fistulas can arise between the esophageal lumen, the mediastinum, the pleura or the intraperitoneal cavity. Endoscopically insufflated CO₂ may escape into these surrounding compartments with subsequent systemic CO₂ accumulation, capnomediastinum, tension capnoperitoneum or pneumothorax. As a result substantial cardiorespiratory instability can arise. Thus, the attending anesthesiologist must be familiar with these typical complications and with specific emergency measures, such as compensatory hyperventilation, percutaneous needle decompression and thoracic drainage. The POEM procedure is a therapeutic innovation and interdisciplinary challenge. However, anesthesia standards of care have not yet been specified. The aim of this review is therefore to outline some clinical recommendations for the daily clinical practice based on existing evidence.

Third Space Endoscopy: Lessons Learnt From a Decade of Submucosal Endoscopy

The field of third space endoscopy (TSE), also called submucosal endoscopy using a mucosal flap valve, allows secure access to the submucosal and deeper layers of the gastrointestinal tract without the risk of a full-thickness perforation. Since the first description of per-oral endoscopic myotomy (POEM) for the treatment of achalasia cardia 10 years ago, this field has expanded rapidly. Several new procedures, submucosal tunneling endoscopic resection, gastric-POEM, Zenker POEM, per-rectal endoscopic myotomy, diverticular POEM, and recanalization for complete esophageal obstruction (per-oral endoscopic tunneling for restoration of the esophagus), have been performed. All TSE procedures employ a similar technique-after a mucosal incision, a submucosal tunnel is created, a myotomy is performed, or a subepithelial tumor is resected distal to the site of mucosal incision, after which the mucosal incision is closed. Potential indications for TSE include resection of subepithelial tumors in the esophagus, gastroesophageal junction, or stomach; refractory gastroparesis; Zenker diverticulum; Hirschsprung disease or other forms of megacolon; and recanalization for complete esophageal obstruction. Data are currently available for POEM, submucosal tunneling endoscopic resection, and gastric-POEM, although mainly in the form of retrospective studies, and randomized trials and long-term follow-up data are limited. Submucosal endoscopy has an excellent safety profile with very few intraoperative adverse events, the majority being related to insufflation, although bleeding, perforation, and sepsis have been reported. TSE procedures require special training and have demonstrated a learning curve.

Outcomes of submucosal tunneling endoscopic resection in upper gastrointestinal sub-epithelial tumors

BACKGROUND

Submucosal tunneling techniques have expanded the horizon of therapeutic endoscopy. One such procedure, submucosal tunneling endoscopic resection (STER), enables the endoscopic removal of gastrointestinal (GI) sub-epithelial tumors. In this study, we aimed to evaluate the safety and efficacy of STER in patients with sub-epithelial lesions localized to the upper GI tract.

METHODS

Consecutive subjects with a sub-epithelial lesion of ≥ 1 cm size in the upper GI tract were enrolled in the study. STER was performed using the standard technique in an endoscopy suite. A modified technique (double-opening STER) was used in cases with difficult en bloc resection of the tumor. Outcome measures included technical success, en bloc resection rates, adverse events, and recurrence.

RESULTS

A total of 104 patients with sub-epithelial tumors were evaluated for STER. Of them, 44 subjects (mean age 44.68 ± 12.82, 52.3% males) underwent standard STER. Majority (31, 70.4%) of the lesions were located in the esophagus and cardia. Technical success and en bloc removal of the tumor were achieved in 97.7% and 88.4% of cases, respectively. There was no major adverse event. Minor adverse events were recorded in 7 (15.9%) cases. Majority (31, 70.4%) of the tumors originated from muscularis propria, followed by submucosa (8, 18.2%) and muscularis mucosa (5, 11.4%). The most common histological diagnosis was leiomyoma (59.1%) followed by GI stromal tumors (20.4%). At a mean follow up of 12.36 ± 7.63 months, there was no incidence of tumor recurrence in en bloc as well as piecemeal resection groups.

CONCLUSION

STER is a safe and efficacious procedure for sub-epithelial tumors in the upper GI tract. Novel strategies need to be developed to ensure en bloc removal of large lesions.

Adverse events during and after per-oral endoscopic myotomy: prevention, diagnosis, and management

Per-oral endoscopic myotomy (POEM) has surfaced as an effective endoscopic treatment modality for achalasia cardia (AC). Promising results in short- and mid-term follow-up studies have increased the use of POEM for the management of AC. POEM can be safely performed in an endoscopy suit, and major adverse events (AEs) are uncommon. AEs encountered during POEM or during the perioperative period principally include insufflation-related AEs, mucosal injuries, bleeding, pain, and aspiration pneumonia. Most insufflation-related AEs do not require an active intervention and therefore should not be considered as AEs in the true sense. When management of AEs is required, most intraoperative AEs can be managed at the same time without untoward consequences. Occurrences of AEs lessen after completion of the learning curve. However, experience alone does not ensure "zero" incidence of AEs, and early recognition remains essential. Postoperative AEs, like leaks, delayed bleeding, and delayed mucosal perforations, may pose special challenges for diagnosis and management. There is no standardized classification system for grading the severity of AEs associated with POEM, resulting in wide variation in their reported occurrences. Uniform reporting of AEs is not only crucial to comprehensively analyze the safety of POEM but also for comparison with other established treatment modalities like Heller's myotomy. GERD is an important long-term AE after POEM. Unlike the perioperative AEs, little is known regarding the intraoperative or patient-related factors that influence the occurrence of post-POEM GERD. Large prospective studies with long-term follow-up are required to determine the procedural factors associated with GERD after POEM.