Botulinum Toxin Pyloroplasty to Reduce Postoperative Nausea and Vomiting After Sleeve Gastrectomy
Condition: Bariatric Surgery; Postoperative Nausea and Vomiting
MeSH terms: Nausea; Vomiting; Postoperative Nausea and Vomiting
Study type: Interventional
Phase: Phase 4

Summary: 
      A common problem following sleeve gastrectomy surgery is called postoperative nausea and
      vomiting (PONV). This problem is uncomfortable for patients, and can also lead to other
      complications, including pneumonia. It is unclear what exactly causes this problem, but it
      may be partly caused by slow emptying of the stomach. The current treatments for PONV include
      medications, but these may only treat the symptoms. Botulinum toxin (BTX, brand name Botox®),
      produced naturally by the bacterium Clostridium botulinum and adapted for medical use, is an
      neurotransmitter inhibitor of the neuromuscular junction, and produces temporary muscular
      paralysis. BTX is widely used in cosmetic and other medical applications. Injecting BTX into
      the pylorus, which is the circular sphincter muscle at the end of the stomach, temporarily
      paralyzes the muscle, leaving it wide open, and allowing stomach contents to flow through.
      This effect lasts for several weeks, and then goes away. This may help prevent PONV.
    

Detailed description: 
      Postoperative nausea and vomiting (PONV) remains a common complaint after bariatric surgery
      such as the sleeve gastrectomy, where the prevalence is estimated to be as high as 60-80%.
      PONV is frequently of greater concern to patients than postoperative pain, decreasing patient
      satisfaction and the perioperative experience. In addition, PONV increases the risk for
      aspiration, dehydration, electrolyte abnormalities, incisional dehiscence, esophageal injury,
      and other adverse events. Finally, PONV delays postoperative diet resumption and increases
      hospital length of stay. Numerous medication regimens have been tried to reduce PONV after
      sleeve gastrectomy, with varying success. A procedure called Botulinum toxin pyloroplasty
      (BP), which involves injection of botulinum toxin into the muscular sphincter at the end of
      the stomach, called the pylorus, has been demonstrated to improve gastric emptying. The
      investigators hypothesize that intraoperative BP during sleeve gastrectomy will decrease
      rates of PONV.

      Botulinum toxin type A (Botox®), produced naturally by the bacterium Clostridium botulinum
      and adapted for medical use, is an inhibitor of the neurotransmitter acetylcholine at the
      neuromuscular junction, producing flaccid muscular paralysis. The effects of Botox® injection
      are temporary and reversible, and its duration of action ranges from weeks to months. Botox®
      injection has been widely used in many contexts, most familiarly during office-based cosmetic
      procedures and also in disorders such as torticollis, spasticity, hyperhidrosis, bladder
      overreactivity, and dystonias. It has been used endoscopically to relieve achalasia and
      dysphagia by injection into the lower esophageal sphincter. Gastroenterologists have reported
      successful treatment of gastroparesis using BP, by relieving the tonic contraction of the
      pylorus and increasing gastric transit time. Postoperative endoscopic BP has been utilized to
      improve gastroparesis following gastrectomy. The use of BP during bariatric surgery has not
      been reported. This proposal represents the first study to evaluate the use of intraoperative
      BP to decrease PONV after sleeve gastrectomy.

      This technique involves pyloroplasty following completion of the robot-assisted laparoscopic
      sleeve gastrectomy. The investigators mix 100 units of Botox® powder in 10ml of saline. Using
      the robot, the investigators inject the pylorus laparoscopically using an 18-gauge, 0.5-inch
      laparoscopic needle. Meanwhile, an assistant surgeon intubates the stomach with an endoscope,
      which the investigators use to assess the gastric staple line and perform a leak test. Prior
      to injection of Botox® into the pylorus, the investigators confirm endoscopically that the
      tip of the needle is not intraluminal. After first aspirating to ensure the needle is
      intramuscular and free from any vascular structures, the investigators then inject the
      pylorus with approximately 5ml of Botox®. Proper placement of the injection is confirmed by
      visualizing a rising weal. The anterior, superior, and inferior aspects of the pylorus are
      injected with approximately 5-6 injections of 1ml each. The posterior aspect of the pylorus
      is not injected, since this is not readily accessible from a laparoscopic approach, and also
      contains the major vascular structure of the pylorus, the gastroduodenal artery.

      This technique has been performed at Albany Medical Center institution more than 200 times
      over the past four years. The Albany Medical Center Bariatric Center as participated in the
      Metabolic and Bariatric Surgery Accreditation for 10 years, and so has collected
      comprehensive and granular data on complication rates and surgical outcomes. Analysis of this
      data demonstrates that enteric use of Botox® is safe.
    

Intervention name(s): Botulinum toxin pyloroplasty; Normal saline pyloric injection
Intervention type(s): Drug; Drug
Intervention description(s): Intraoperative laparoscopic injection of Botulinum toxin into the pylorus immediately following sleeve gastrectomy; Intraoperative laparoscopic injection of normal saline into the pylorus immediately following sleeve gastrectomy
Other intervention name(s): Botox pyloropasty; Botulinum toxin A pyloroplasty
Intervention MeSH terms: Botulinum Toxins; Botulinum Toxins, Type A
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment