Intrapyloric Botulinum Toxin Injection for Refractory Nausea and Vomiting in Pediatric Patients.

OBJECTIVES: Chronic nausea and vomiting may be associated with gastroparesis or other conditions. Poor mechanistic understanding of symptoms often precludes targeted therapy. Numerous case series suggest that intrapyloric botulinum toxin injection (IPBI) may be beneficial in treating gastroparesis and dyspepsia in children. We hypothesized that nausea, vomiting, and other symptoms, independent of gastroparesis, may improve with IPBI. We sought to identify gastric emptying (GE) and manometric patterns in IPBI responders versus nonresponders. METHODS: Electronic records of 25 pediatric patients who received IPBI for refractory nausea, vomiting, or both were retrospectively reviewed. We assessed symptom improvement post-IPBI and compared symptoms, GE, and antroduodenal manometry (ADM) findings between IPBI responders and nonresponders. RESULTS: At least one major symptom improved in 19 patients (76%) after IPBI. Of 22 patients completing a GE study, 14 had delayed GE with no significant difference between IPBI responders and nonresponders. Of 22 patients who underwent ADM, 18 had normal fasting peristalsis, 5 had postprandial antral hypomotility, 4 had neuropathic findings, and 19 had pylorospasm. IPBI responders, compared to nonresponders, demonstrated higher antral pressures with feeding ( P < 0.0001) and shorter duration of pylorospasm ( P = 0.0036). Antral pressures did not differ significantly with fasting or following motilin agonists. CONCLUSIONS: Our findings suggest that IPBI may have therapeutic benefit in pediatric patients with chronic nausea and/or vomiting, independent of gastroparesis. ADM findings of intact antral peristalsis and elevated antral pressures, in conjunction with efficacy of IPBI, support pyloric non-relaxation as a potential contributor to nausea and/or vomiting in pediatric patients.

Case Report: Superior Mesenteric Artery Syndrome in an Adolescent With Cannabinoid Hyperemesis.

Background: Superior mesenteric artery syndrome (SMAS) occurs when the third portion of the duodenum is compressed between the superior mesenteric artery (SMA) and the aorta, causing duodenal obstruction. This condition most commonly arises from marked weight loss that reduces the size of the fat pad between these vessels, causing greater acuity of angulation. We present an unusual case of SMAS occurring in an adolescent due to precipitous weight loss resulting from cannabinoid hyperemesis syndrome (CHS). Case Presentation: A 17-year-old adolescent presented emergently with voluminous bilious emesis. She endorsed a history of recent weight loss and a longstanding history of chronic heavy cannabis use associated with recurrent nausea and vomiting. Her chronic symptoms satisfied the Rome IV criteria for cannabinoid hyperemesis syndrome, but her acute vomiting symptoms were more extreme. Evaluation was significant for mild abdominal tenderness and fullness of the epigastrium. Contrast abdominal CT demonstrated moderate gastric and proximal duodenal distention with tapering of the lumen between the SMA and the aorta, consistent with SMAS. Conclusions: To our knowledge, this is the first reported case of SMAS occurring as the result of CHS. Clinicians should be aware of this possible juxtaposition, when a patient with a history of chronic excessive cannabis use, stereotypical vomiting resembling cyclic vomiting syndrome, and considerable rapid weight loss presents with a sudden exacerbation of symptoms, even when a normal BMI is maintained.