Objective:To study the neuromuscular junction of the colon in patients with Hirschsprung’s disease by immunohistochemical methods.Methods:The distribution of the neuromuscular junction in the muscle layers of bowel from 10 normal controls and 20 Hirschsprung’s disease patients was studied by synaptophysin immunohistochemistry.Antimouse synaptophysin serum was used for visualization of neuromuscular junction.Results:In the colon of the control cases,synaptophysin-immunoreactivity was widely distributed in the circular muscle layer.In the dilated colon with Hirschsprung’s disease cases,synaptophysin-immunoreactivity was moderately distributed within normal ganglion cell and scarcely in constricted segment within degenerated ganglion cell.In contrast to the high degree of synaptophysin-immunoreactivity in the controls and dilated colon,the synaptophysin-immunoreactivity in the constricted segment were nil in the circular muscle layer.Conclutions:Dense synaptophysin-immunoreactivity nerve endings were prominent in the circular muscle layer in the control and there was almost no synaptophysin imm-unoreactivity activity in the circular muscle layer in the constricted segment.The circular muscle layer from the constricted segment is confirmed to be a region with poor innervation including extrinsic and intrinsic nerve. Based on the Cannon’s Law of Denervation,the muscles that are supplied by these nerves shorten and tighten,resulting in muscle spasm and stiffness.The constricted segment which was denervated,is incapable of transmitting normal propulsive peristaltic waves and therefore acts as a physiologic obstruction.

Objective:The feasibility of a minimally invasive cosmetic transbilical laparotomy was studied in fifty-seven pediatric patients.The advantages of this technique will be discussed.Methods:The circumferential incision was made following the ring fold of the right umblilicus,which was less than 2700.The peritoneum was opened in the midline via rectus abdominis.Intra-peritoneal lesions were detected and explored.The surgical procedures were able to be carried out either inside or outside of the peritoneum.After closure of peritoneum,the umbilical incision was closed subcutaneously with an absorbable suture.Results:From January 2001 to January 2005,58 procedures via transumbilical route have been done in 57 pediatric patients.None of those cases required conversion to a traditional abdominal incision.The duration of surgery was from 20 to 170 minutes.All patients were discharged five days postoperatively and follow-up was conducted from 3 months to 4 years.No complications were observed in all but one patient.This patient had a leaking anastamosis.No visible scars were present and the cosmetic results were excellent.All patients had shorter hospital stay and lower operating cost.Conclusion:Transumbilical approach is a feasible,safe,economical,minimally invasive procedure with excellent cosmetic results which appears to be superior to traditional procedures.It suggests that the transumbilical route should be widely used clinically and might be applicable for elder children and possibly would be of benefit in the treatment of other conditions.