New Onset Chronic Intestinal Pseudo-Obstruction Following Nephrectomy

Introduction: Chronic intestinal pseudo-obstruction (CIPO) is a rare condition which causes impaired intestinal motility and presents with abdominal distension, pain, constipation, nausea, and vomiting. CIPO can arise spontaneously or be associated with an underlying medical condition. While acute colonic pseudo obstruction is seen after surgery, surgery-related CIPO is uncommon. Case Description/Methods: An 85-year-old man had laparoscopic partial nephrectomy for renal cancer and was discharged without any immediate complications. Postoperatively, he experienced bloating, distension and irregular bowel movements. Despite weaning off narcotic analgesics, his symptoms worsened leading to hospitalization 8 months later. Physical examination showed a distended abdomen without tenderness and sluggish bowel sounds. Blood work showed mild leukocytosis and normal electrolytes. Imaging revealed colon distention without obstruction (Figure 1). Colonoscopy confirmed a distended colon without obstruction. Random colon biopsies were normal. Conservative management with a rectal tube, senna, and polyethylene glycol was initiated and patient was discharged home. A month later, abdominal distension and discomfort recurred. Repeat imaging confirmed colonic distension, and a diagnosis of CIPO was made. Treatment included pyridostigmine and rifaximin for SIBO. Within a week of starting treatment, symptoms improved and repeat imaging showed resolution of colonic distension. Discussion: CIPO can result from systemic diseases such as autoimmune disorders, muscular dystrophy and neuropathies. These causes account for up to 50% of adult CIPO cases. CIPO can also be part of paraneoplastic syndrome but tumor resection leads to its resolution. In our case, the development of CIPO after tumor resection makes it less likely to be associated with paraneoplastic syndrome. Postoperative occurrence of CIPO is rare, and the underlying mechanism remains unclear, but one theory suggests that damage to parasympathetic nerves during surgery can impair motility. Diagnosing CIPO involves imaging tests and endoscopic evaluation, full thickness biopsies and manometry. The current treatment approach for CIPO focuses on restoring fluid and electrolyte balance and addressing bacterial overgrowth. Acetylcholinesterase inhibitors (ACIs) like pyridostigmine enhances gastrointestinal motility by preventing the breakdown of acetylcholine. Prucalopride, a 5-HT4 receptor agonist, is another option that promotes the release of acetylcholine.Figure 1.: CT scan showing colon distension.