View source for Heller Myotomy (Laparoscopic)

'''Laparoscopic Heller Myotomy Wiki Page'''

PDF Version with Images --[https://drive.google.com/file/d/1l1LRSCW9XSp--_pQQ9_BH9MwzUZyIgRO/view?usp=sharing Heller Myotomy] (Laparoscopic)

* Objectives:
** Understand surgical indications for Heller myotomy and alternatives
** Understand relevant anatomy and physiology
** Describe the anesthetic management of Heller myotomy
* Indications and alternatives:
** Achalasia is the main indication for laparoscopic Heller myotomy. Achalasia is a disorder of esophageal motility of unknown etiology classically associated with increased tone of the lower esophageal sphincter (LES) and aperistalsis of the distal esophageal smooth muscle, possibly due to selective loss of inhibitory neurons in the myenteric plexus in the LES and distal esophagus. 
** Achalasia affects ~2-13 per 100,000 persons per year, equally men and women with peak incidence around 30-60 years old. Typical symptoms of achalasia include progressively worsening dysphagia to solids and then liquids, burning chest pain, heartburn, and eventually weight loss and nutritional deficiency if left untreated. 
** There are multiple treatment options for achalasia, ranging from pharmacologic therapy to endoscopic procedures to surgical myotomy.
** Surgical myotomy is one of the most effective and common definitive treatment options for achalasia. Initially myotomy was performed through a thoracotomy, however the current practice is the laparoscopic approach which has shown decreased mortality and faster recovery. Because there is an  ~30% risk of developing GERD after a myotomy, a fundoplication (folding of fundus around LES to reduce distal esophageal acid exposure) is typically performed at the same time.
** Other treatment options include botulinum toxin injection into LES, PO pharmacotherapy with calcium channel blockers or nitrates, pneumatic esophageal dilation, and most recently, peroral endoscopic myotomy (POEM) that frequently eliminates the need for laparoscopy.

Relevant anatomy and physiology:

* The esophagus is a hollow muscular organ (cervical esophagus contains striated muscle, thoracic esophagus contains smooth muscle), it runs anterior to the aorta below T8 and enters the abdominal cavity through an opening of the diaphragm located anterior to the opening for descending aorta.
* LES tone affected by several medications commonly used in anesthesia practice:
** Drugs that decrease LES pressure: anticholinergics, nitroprusside, dopamine, beta agonists, TCAs, opioids.
** Drugs that increase LES pressure: anticholinesterases, metoclopramide, prochlorperazine, metoprolol.
* Blood supply to the thoracic esophagus comes from paired aortic esophageal arteries or terminal branches of bronchial arteries. The blood supply to LES and most distal part of the esophagus comes from the left gastric artery and a branch of the left phrenic artery.
* Vagal afferents coming from the esophageal smooth muscle layer and serosa are sensitive to stretch. Due to convergence of sensory afferents from the heart and esophagus on same dorsal spinal horn neuron in cervical and thoracic spinal cord, esophageal pain may present similarly to cardiac pain.

* Anesthetic management
** Preop evaluation
*** Perform a thorough history and physical focusing on signs/symptoms of esophageal obstruction, severity of dysphagia, signs/symptoms of active GERD and aspiration. 
*** If patient reports chest pain/other symptoms that may be of cardiac etiology, even though these symptoms may be attributed to achalasia, it may be reasonable to obtain additional cardiac workup to assess for myocardial ischemia or arrythmias.
*** Ensure patient is appropriately NPO given high risk of aspiration in this patient population, longer NPO status may be beneficial. If the risk of aspiration is high, consider pretreating the patient with nonparticulate antacids or gastric acid secretion blockers (i.e H2 blockers) to decrease the risk and severity of pneumonitis if aspiration occurs.
*** If there is a concern for aspiration pneumonia/pneumonitis, a CXR may be reasonable to obtain. [GA1] 
** General case considerations
*** Anesthetic type: GETA with paralysis.
*** Airway management: Given high risk of aspiration in this patient population, RSI and intubation with head of the bed at 30 degrees is recommended if difficult airway is not anticipated. If there is a concern for difficult airway, consider awake intubation given high risk of aspiration with masking. Ensure airway is secure if intraoperative EGD is performed by the surgical team.
*** Access: one PIV is typically sufficient.
*** Monitors: standard ASA monitors +/- invasive monitors if guided by patient's comorbidities.
*** Positioning: reverse Trendelenberg.
*** Pain management considerations: typically post-procedure pain is not particularly severe.
*** Other considerations: Aggressive PONV prophylaxis is helpful. Esophageal perforation is a possible early complication of laparoscopic Heller's myotomy and can be detected intraoperatively, one review estimates the prevalence of this complication to be ~7%. 
* Post-op considerations
** Most patients are extubated at the end of surgery. NGT typically not necessary. 
* Resources used and links
** Vaezi MF, Pandolfino JE, Yadlapati RH, Greer KB, Kavitt RT. ACG clinical guidelines: diagnosis and management of achalasia. Official journal of the American College of Gastroenterology| ACG. 2020 Sep 1;115(9):1393-411.
** Yazaki E, Sifrim D. Anatomy and physiology of the esophageal body. Diseases of the Esophagus. 2012 May 1;25(4):292-8.
** Blank RS, Collins SR, Huffmyer JL, Jaeger JM. Anesthesia for esophageal surgery. InPrinciples and practice of anesthesia for thoracic surgery 2019 (pp. 609-649). Springer, Cham.
** AlHajjaj GM, AlTaweel FY, AlQunais RA, Alshammasi ZH, Alshomimi SJ. Iatrogenic Esophageal Perforation After Laparoscopic Heller’s Myotomy Treated Successfully with Endoscopic Stent: Case Report and Literature Review. The American Journal of Case Reports. 2021;22:e931677-1.
** Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures: '''An Updated Report by the American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration'''. ''Anesthesiology'' 2017; 126:376–393
**
* Contributors
** Anastasia Piersa
** Diana Barragan Bradford

----[GA1]I would probably delete this sentence since if you are concerned about this you would cancel the case, since it’s elective surgery