3099 Endoscopic Botulinum Toxin Injection for Tacrolimus-Induced Achalasia in a Renal Transplant Recipient

Abstract

INTRODUCTION: Multiple medications have been associated with secondary achalasia. Here we present a patient who developed dysphagia 4 days after his renal transplant and was found to have achalasia thought to be due to his tacrolimus; he was successfully treated with botulinum injection. To our knowledge, this is the first case of tacrolimus-induced achalasia ever reported in a renal transplant patient; it is also the first case in a transplant patient to be treated endoscopically with botulinum injection. CASE DESCRIPTION/METHODS: A 58 year old man with a history of end stage renal disease secondary to focal segmental glomerulosclerosis presented with progressive renal failure and underwent deceased kidney transplant without complications. At clinic, follow-up on post-operative day #4, the patient reported difficulty in swallowing since post-operative day two. A modified barium swallow study (Figure 1) demonstrated severe esophageal dysmotility and lower esophageal sphincter dysfunction concerning for achalasia. Upper endoscopy (Figure 2) one week later revealed a dilated esophagus with mild edema but without focal lesions or ulcerations. Esophageal manometry (Figure 3) evidenced outflow obstruction of the esophagogastric junction and weak peristalsis in the esophageal body, confirming the diagnosis of achalasia. Surgical therapy and changing his calcineuron inhibitor for achalasia were considered too high risk in this patient so shortly after transplant. The patient ultimately underwent therapy with endoscopic botulinum toxin injection (100 units) of the lower esophageal sphincter. He had excellent results with immediate and complete resolution of dysphagia. DISCUSSION: The proposed mechanism for CNI induced changes in esophageal motility involves inhibition of nitric oxide synthase by CNIs. Nitric oxide (NO) is responsible for esophageal peristalsis as well as relaxation of the lower esophageal sphincter (LES). Although it is unclear why switching between different CNIs would lead to symptom resolution, individual variation in the reaction to the different chemical structures of tacrolimus and cyclosporine has been proposed. Botulinum toxin can be considered as a therapeutic option in those patients who are not candidates for a change in their immunosupression. To our knowledge, this is the first case of botulinum induced achalasia reported after a kidney transplant and also the first successfully treated with botulinum toxin injection.