Introduction
Hereditary hollow viscus myopathy is a disorder where the intestines cannot contract normally and push food through the digestive system, causing an obstruction. The affected walls of the gastrointestinal (GI) tract become thin, and the muscles that control its motions begin to degenerate. It can range from mild to severe.
What Is Hereditary Hollow Viscus Myopathy?
Hereditary hollow viscus myopathy (HMV) is a digestive disorder causing pseudo-intestinal obstructions. This is a disorder where the intestines cannot contract normally and push food through the digestive system, causing an obstruction. The affected walls of the gastrointestinal (GI) tract become thin, and the muscles that control its motions begin to degenerate. It can range from mild to severe. In severe cases, urinary tract and bladder associations have been observed. There is no exact treatment for this condition, which is treated symptomatically. The diagnosis of hereditary hollow viscus myopathy is complicated. Neither conservative treatment nor surgical approaches have proven fruitful in treating this condition.
What Are the Other Names for Hereditary Hollow Viscous Myopathy?
Hereditary Hollow Viscous myopathy is also known as;
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ACTG2 Visceral myopathy.
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Berdon Syndrome.
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Familial Visceral myopathy.
What Are the Causes of Hereditary Hollow Viscus Myopathy?
The exact cause of Hollow viscus myopathy (HVM) is unknown. However, it is thought to be due to the following:
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Inherited.
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Idiopathic.
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Secondary to other diseases like endocrine disorders, scleroderma, etc.
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Drugs.
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Toxins.
What Are the Symptoms of Hereditary Hollow Viscus Myopathy?
Patients with HVM may vary in their presenting symptoms; some may be asymptomatic, some might show mild abdominal symptoms, and a few others might have recurrent attacks of bowel obstruction. No biliary or uterine dysfunctions have been reported. Few patients reported having repeated urinary tract infections or urinary retention. The most commonly presented symptoms include:
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Vomiting.
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Constipation.
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Urological abnormalities.
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Short or dilated small bowel.
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Severe abdominal pain.
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Urinary tract infections.
How Is Hereditary Hollow Viscus Myopathy Diagnosed?
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The diagnostic criteria behind the condition are to find no mechanical obstruction and the histologic examination of the cells. To exclude mechanical obstruction, plain abdominal radiography, CT (computed tomography), MRI (magnetic resonance imaging), and in some cases, endoscopy may be required.
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The diagnosis can be delayed due to the rarity of the condition, the great variation in symptoms, and the numerous similarities it has with other GI diseases. Moreover, there are almost no specific radiologic features that indicate this condition.
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The histologic examination can reveal degenerative changes in myocytes, fibrocytes, and partial or complete defects in the lamina propria. Light microscopy reveals degeneration, thinning, and fibrous replacement of the smooth muscles in the GI tract. Myopathy would potentially involve the external longitudinal layer of muscularis propria characterized by the degeneration of smooth muscles, distinguishing it from progressive systemic sclerosis.
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Manometric evaluation (a test that measures the pressure and constriction of the muscles) is more sensitive than imaging tests, as it enables evaluation of the intensity and coordination of the digestive tract. It also helps to identify whether intestinal dysmotility is due to neuropathy or myopathic pathophysiology.
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Hirschsprung's disease, pseudo-Hirschsprung's disease, progressive systemic sclerosis involving the gut, age-related neuropathies, and segmental absence of intestinal musculature are some other GI tract disorders to be taken into account when diagnosing.
How Is Hereditary Hollow Viscus Myopathy Treated?
Treating hereditary hollow viscus myopathy requires a multidisciplinary approach involving gastroenterology, urology, a dietitian, and surgery. Mild relief of the presenting symptoms may require decompression with a nasogastric tube and rectal tube insertion. If this fails, decompression with a colonoscopy can be performed. Typically, if no perforation is noted, then the primary management would involve non-operative conservative management that may involve a diet rich in fiber or bulk management, fecal disimpaction involving suppositories and enema, correction of electrolyte abnormalities, and removing aggravating factors like narcotics, calcium channel blockers, or cholinergic drugs. However, if dilatation persists, the operative options include total colectomy with an ileorectal anastomosis or total colectomy with end ileostomy, with the former being the treatment of choice.
How Is Hereditary Hollow Viscus Myopathy Managed?
Being a rare condition, managing hereditary hollow viscus myopathy can be challenging. There is no evidence-based mode of treatment for this condition; rather, symptom-based treatment is usually followed. Specialized centers provide integrative medical and surgical modes of treatment, including comprehensive total parenteral nutrition (TPN) management and multi-visceral transplantation.
Chronic bladder dysfunction may require a urologist and routine urinary catheterization or diversion to reduce the risk of upper urinary tract dilation and the associated urinary tract infections and renal functional impairments. In addition, bowel dysfunction, microcolon (a genetic disorder caused by the mutation of one or more genes that controls the muscles of the intestines and the bladder), intestinal dysmotility, and other related gastrointestinal comorbidities would require a gastroenterologist and a nutritionist familiar with intestinal motility disorders.
Examinations should be individualized using a multidisciplinary approach.
1) Monitor voiding, examine the anatomy of the urinary tract, and evaluate renal functions for bladder and urinary tract disorders.
2) Monitor nutritional status and possible TPN-related complications like line disorder and liver diseases for intestinal manifestations.
3) Medications to be avoided. Treatments or medications that involve or diminish bowel and bladder motility should be avoided or limited.
4) At-risk relatives' assessment should be carried out. Clarifying the genetic status of at-risk relatives would be appropriate, as early diagnosis can help prevent unnecessary surgery and allow for the evaluation of bladder and renal functions and the urinary tract for dilation.
5) Pregnancy management: A maternal-fetal medicine specialist should be consulted when a fetus is at risk for the condition.
Conclusion
The hereditary hollow viscus myopathy diagnosis is complicated, as it mimics many other GI disorders. However, visceral myopathy can be considered among patients with long-lasting or recurrent abdominal distension without evidence of mechanical obstruction, constipation, and intermittent abdominal pain. Moreover, aggressive surgical treatment of patients with hereditary hollow viscus myopathy-caused chronic intestinal pseudo-obstruction can be associated with a poor prognosis.
The condition can have a negative impact on one's quality of life, and predicting the prognosis can be difficult. Therefore, the treatment of hereditary hollow viscus myopathy should be based on the symptoms in each individual, as there is no standardized mode of treatment due to its rarity.
