Intestinal Pseudoobstruction Caused by Neuronal Disease

Functional intestinal obstruction associated with a variety of pathologic conditions. Colonic motility disorder associated with characteristic histochemical changes of the bowel wall.

Chronic Idiopathic Pseudoobstruction; Deficiency of Argyrophil Myenteric Plexus; Intestinal Neuronal Dysplasia (IND) Type A; Neuronal Intestinal Dysplasia.

Fewer than 20 patients have been reported.

Sporadic, autosomal dominant, and autosomal recessive.

Wide spectrum of pathologic disorders: (1) neuronal intestinal dysplasia (NID) type A: hypoplasia or aplasia of the intestinal sympathetic innervation; (2) NID type B: hyperplasia of the submucosal parasympathetic plexus; and (3) other diseases: degenerative processes involving the myenteric plexus, combinations of NID B and aganglionosis (Hirschsprung), or hypoganglionosis. This group of disorders results in ineffective intestinal propulsion with various degrees of aperistalsis and clinical manifestations.

Clinical course. NID A: Younger than 6 months with bloody stools and spastic diarrhea (in cases with immaturity of the sympathetic innervation: complete cessation of the ulcerative colitis after temporary colostomy). NID B: Severe constipation, subileus, sometimes attacks of or persistent malabsorption (treatment usually conservative). Although NID B appears clinically similar to Hirschsprung disease, there is no aganglionosis of intramural plexuses. NID B may be associated with intestinal malrotation, short bowel syndrome, ileal stenosis, colonic atresia, or multiple endocrine neoplasias type II (MEN IIA and IIB). Some infants with pyloric hypertrophy have an associated functional intestinal obstruction with small intestine malrotation and short bowel syndrome. Chronic neuropathic intestinal pseudoobstruction with ophthalmoplegia, ptosis, hearing loss, and severe sensory and motor peripheral neuropathy also described. Radiographic examination, electromanometry, and transit time studies do not show pathognomonic criteria for specific neuronal intestinal manifestations. Biopsies with histoimmunologic and histochemical analysis of the involved areas give the final diagnosis.

As described under Diagnosis: wide spectrum of recurrent episodes of intestinal obstruction in the absence of a mechanical blockage of the lumen; occasional history of prenatal oligohydramnios; and failure to thrive (some patients may be so malnourished that they require total parenteral nutrition with its potential adverse effects). Consider the possibility of associated gastrointestinal, endocrine, and neurologic manifestations.

Obtain full history of gastrointestinal symptoms, failure to thrive, and associated endocrine or neurologic diseases. Evaluate patient's intravascular volume status: clinically, plasma electrolytes, coagulation profile, and hemoglobin level. If on total parenteral nutrition, obtain albumin, glucose, phosphate, calcium, and magnesium levels, liver function tests. In rare cases of associated MEN IIA (medullary thyroid carcinoma, parathyroid adenoma, pheochromocytoma) or MEN IIB (medullary thyroid carcinoma, mucosal neuromas [tongue, buccal mucosa, lips, conjunctivae, pheochromocytoma]): request endocrine consultation.

Optimization of fluid status most recommended prior to anesthesia. Rapid-sequence induction in the presence of intestinal obstruction or pseudoobstruction (use nondepolarizing muscle relaxants if associated myopathy); intraoperative blood glucose levels if on total parenteral nutrition. Expect prolonged postoperative mechanical ventilation if associated peripheral neuropathy affecting respiratory muscles or in presence of muscular hypotonia with MEN IIB. If MEN IIA or IIB associated with NID B: continue antihypertensive therapy, carefully monitor blood pressure (arterial indwelling catheter). One must consider the need for steroids and/or thyroid hormone supplements in patients who had a thyroidectomy (if not done, consult with endocrinologist to keep the patient as euthyroid as possible).

Careful titration (nerve stimulator) of muscle relaxants in the presence of peripheral neuropathy or with muscular hypotonia (avoid succinylcholine). If significant degree of malnutrition or if depressed liver and renal function secondary to complications of total parenteral nutrition, cautiously titrate all anesthetic drugs (low protein: α1-acid glycoprotein and albumin cause decreased drug binding and higher free drug level).

Hirschsprung Syndrome: Congenital chronic obstruction of the colon because of complete absence of myenteric plexuses in the distal part of the gastrointestinal tract resulting in a tonically contracted aganglionic segment with a dilated segment above it (megacolon). It is caused by the absence of migration of neuroblasts into the gut epithelium from the vagal nerve trunks at the end of first trimester of intrauterine life.