Pathology of Intestinal Motor Disorders in Children

Latest developments in chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction presenting as symptoms of intestinal obstruction but without actual mechanical obstruction. An extremely low incidence, non-specific clinical symptoms, strong heterogeneity, and no definitive cause in some patients make CIPO very difficult to diagnose correctly. Imaging and gastrointestinal manometry are commonly used. Most patients have progressive worsening of their symptoms and require intervention, and nutritional assessment and treatment are very important to determine the prognosis. With improvements in surgical techniques, small bowel transplantation is a feasible treatment option for patients with advanced CIPO; however, the long-term prognosis for CIPO patients remains unsatisfactory. Generally, the disease is rare and difficult to diagnose, which leads to clinicians’ lack of understanding of the disease and results in a high rate of misdiagnosis. This review describes the characteristics of CIPO and the latest developments in diagnosis and treatment, in detail. The goal of our review is to improve clinicians' understanding of CIPO so that the disease is identified quickly and accurately, and treated as early as possible to improve patients’ quality of life.

Transplantation, gene therapy and intestinal pathology in MNGIE patients and mice

Background

Gastrointestinal complications are the main cause of death in patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). Available treatments often restore biochemical homeostasis, but fail to cure gastrointestinal symptoms.

Methods

We evaluated the small intestine neuromuscular pathology of an untreated MNGIE patient and two recipients of hematopoietic stem cells, focusing on enteric neurons and glia. Additionally, we evaluated the intestinal neuromuscular pathology in a mouse model of MNGIE treated with hematopoietic stem cell gene therapy. Quantification of muscle wall thickness and ganglion cell density was performed blind to the genotype with ImageJ. Significance of differences between groups was determined by two-tailed Mann-Whitney U test (P < 0.05).

Results

Our data confirm that MNGIE presents with muscle atrophy and loss of Cajal cells and CD117/c-kit immunoreactivity in the small intestine. We also show that hematopoietic stem cell transplantation does not benefit human intestinal pathology at least on short-term.

Conclusions

We suggest that hematopoietic stem cell transplantation may be insufficient to restore intestinal neuropathology, especially at later stages of MNGIE. As interstitial Cajal cells and their networks play a key role in development of gastrointestinal dysmotility, alternative therapeutic approaches taking absence of these cells into account could be required.

Chronic Intestinal Pseudo-obstruction

Chronic intestinal pseudo-obstruction (CIP) is defined by either continuous or intermittent symptoms of bowel obstruction in the absence of fixed lumen excluding lesion. CIP includes a heterogeneous group of disorders which result either from diseases affecting the enteric neurons and smooth muscle lining or those involving the autonomic innervation of the bowel. Symptoms associated with CIP are nonspecific, which can sometimes contribute to the delay in recognizing the condition and making the correct diagnosis. The diagnostic workup should include imaging and manometry studies and, occasionally, full-thickness bowel biopsies for histopathological examination may be required. Multidisciplinary team approach for the management of these patients is recommended, and the team members should include a gastroenterologist, surgeon, chronic pain specialist, clinical nutritionist, and a psychologist. The treatment goals should include optimizing the nutritional status and preventing or delaying the development of intestinal failure. The majority of the patients require enteral or parenteral nutrition support, and chronic pain is a common and distressing symptom. Small bowel transplantation may be required if patients develop liver complications due to parenteral nutrition, have difficult central line access, or have poor quality of life and worsening pain despite aggressive medical management.

Diffuse Intestinal Ganglioneuromatosis Showing Multiple Large Bowel Ulcers in a Patient with Neurofibromatosis Type 1

A 67-year-old Japanese man with neurofibromatosis type 1 underwent right hemicolectomy owing to abscess formation around the cecum. A pathological analysis revealed diffuse intestinal ganglioneuromatosis in the cecum and colon. Colonoscopy performed eight months after hemicolectomy revealed multiple ulcers throughout the colon and rectum. The colorectal ulcers failed to respond to conservative treatment and ultimately required surgical resection. Diffuse ganglioneuromatosis was observed again in the resected specimen. This report illustrates a rare manifestation of diffuse intestinal ganglioneuromatosis in a patient with neurofibromatosis type 1.

Building a brain in the gut: development of the enteric nervous system

The enteric nervous system (ENS), the intrinsic innervation of the gastrointestinal tract, is an essential component of the gut neuromusculature and controls many aspects of gut function, including coordinated muscular peristalsis. The ENS is entirely derived from neural crest cells (NCC) which undergo a number of key processes, including extensive migration into and along the gut, proliferation, and differentiation into enteric neurons and glia, during embryogenesis and fetal life. These mechanisms are under the molecular control of numerous signaling pathways, transcription factors, neurotrophic factors and extracellular matrix components. Failure in these processes and consequent abnormal ENS development can result in so-called enteric neuropathies, arguably the best characterized of which is the congenital disorder Hirschsprung disease (HSCR), or aganglionic megacolon. This review focuses on the molecular and genetic factors regulating ENS development from NCC, the clinical genetics of HSCR and its associated syndromes, and recent advances aimed at improving our understanding and treatment of enteric neuropathies.