Hollow Visceral Myopathy

Hollow Visceral Myopathy

2016 - Shel Ravi

Complications (Urinary)

• Megacystis during gestation can lead to foetal demise
• Recurrent UTI
• Renal impairment
• Incontinence

ACTG 2 Gene

Management (GIT)

Cytogenetic Location: 2p13.1

Prognosis

• Hydrolysed formula
• Prokinetic agents (Cisapride etc)
• Aperients often needing regular enemas
• NBM with Parenteral Nutrition
• Antibiotic prophylaxis to prevent overgrowth
• Resection commonly necessary to relieve obstructive symptoms with subsequent ileostomy formation

Inheritance Pattern - Finish family with 7 affected

JPGN - American study with 23 patients

• Most survive beyond infancy
• Only 22% weaned off TPN
• 52% either died or required bowel transplant
• Overall Mortality is ~40%

Pathogenesis

Signs and Symptoms (Severe cases)

• Bowel is always affected with around half of cases also involving the genitourinary tract
• Pathology is usually isolated to the muscularis propria and most severely affects the longitudinal layer however begins in circular layer
• Small bowel is most severely affected with large bowel only sparingly involved
• End result is impaired peristalsis

• Often begins in foetal/neonatal period
• Delayed meconium
• Abdominal distension
• Vomiting (bilious and non)
• Failure to thrive
• Megacystis microcolon intestinal hypoperistalsis syndrome

And into the lab...

Back to school...

More lab stuff...

Definition

Investigations

• Plain films: Distended bowel loops with proximal obstruction at the duodenum the most common site. Usually only seen in severe cases
• Abdominal U/S: Low yield, useful for exclusion purposes
• CT:Low yield
• Contrast study: Reveals prolonged transit times

Normal smooth muscle

Smooth muscle in HVM

Rare inheritable form of myopathic pseudo-obstruction

(most cases are sporadic)

<1/200,000 quoted in American literature

Limited knowledge on condition

Signs and Symptoms (mild to mod)

Method of inheritance can be autosomal dominant or recessive

• Periodic abdominal pain
• Constipation
• Recurrent urinary tract infections
• Urinary urgency, frequency and enuresis

ACTG2 gene is heavily implicated in pathogenesis of disease however is not only gene defect identified

Management (Urinary)

• Urethral catherisation used in initial stages
• Surgical formation of vesicostomy (Mitrofanoff procedure) often required later

Investigations

Endoscopy/Colonoscopy:

• Useful to exclude anatomical lesions and to visualise peristaltic activity
• Biopsy to exclude Hirschprung’s (enteric neuropathy) but often normal in HVM due to depth of tissue sample
• Full thickness biopsy is necessary to accurately diagnose HVM and thus necessitates laparotomy

Mitrofanoff Procedure

Complications (GIT)

• Acute small bowel obstruction
• Malnutrition
• Bacterial overgrowth syndrome
• Persistent diarrhoea