Sing Shang Ngoi

Trends of diverticular disease of the large bowel in a newly developed country

Five hundred twenty four consecutive barium enemas done over an 18-month period were reviewed in Singapore to ascertain the prevalence and distribution of diverticular disease in the large bowel. In this study, the prevalence rate was 20 percent, which is comparable to European and American studies but higher than similar studies in Asian countries. However, the distribution of the disease showed a predominance of right-sided disease (70 percent). This is a pattern that is markedly different from that seen in Europe and North America, where the disease involves largely the left side of the large bowel. The high prevalence rate in this series is at variance with the widely held belief that diverticulosis occurs less frequently in oriental communities.

Surgical management of right colon diverticulitis.

The infrequent occurrence of right colon diverticulitis in the developed West has led to a controversy in the management of this disease. In Singapore, we continued to avoid colectomy whenever possible because this disease is usually nonprogressive. We reviewed 68 patients treated by conservative surgery to evaluate the effectiveness of this treatment policy. Almost 70 percent of our patients were below 40 years of age, and the clinical presentation was indistinguishable from acute appendicitis. Diverticulectomy was done only for inflamed and perforated diverticula (25 cases), while the nonperforated diverticulum was left alone (40 cases). The inflammation invariably responded to antibiotic therapy. Only three patients had colonic resection since a malignant neoplasm could not be excluded. There were no adverse sequelae over a mean follow-up period of three and onehalf years, except for one patient who had recurrent attacks of right colon diverticulitis necessitating colectomy. With this policy of management we encountered no mortality, and morbidity was acceptable.

Diagnostic laparoscopy: Reducing the number of normal appendectomies

A prospective, controlled study was conducted to determine whether a selective policy of diagnostic laparoscopy could reduce the number of unnecessary normal appendectomies in patients with acute right iliac fossa pain. The cohort consisted of patients admitted with acute right iliac fossa pain by the emergency department. Of 102 patients in the study group, 28 subsequently required a diagnostic laparoscopy when a definite diagnosis could not be reached after 8 to 12 hours of observation. Of these, only 18 had inflamed appendices, which were removed. In the rest of the patients (10), the appendices were normal and unnecessary laparotomies were avoided. In the control group, wherein equivocal cases were laparotomized after a similar period of observation, there was a normal appendectomy rate of 15.7 percent (P<0.05). There was no significant difference in the incidence of perforation between the control and study groups. Diagnostic laparoscopy in equivocal cases could thus significantly reduce the number of unnecessary appendectomies without compromising on the rate of perforation.

Novel alternative splicing predicts a secreted extracellular isoform of the human receptor-like protein tyrosine phosphatase LAR

RT-PCR was used to examine the expression of LAR (encoding the leukocyte-common antigen-related protein tyrosine phosphatase) in normal human colon mucosa, and colon polyps and tumors. Although the LAR protein was not detected in the colon in a previous immunohistochemical study, amplification of a region of LAR between the most membrane proximal (eighth) fibronectin type-III (FN-III) repeat and the transmembrane domain demonstrated LAR expression in all samples, but showed no difference in expression within matched samples from each patient examined. An additional minor fragment amplified in all reactions was consistently observed in colon and various cell line samples using this and two other LAR-specific sets of primers. Cloning and sequencing of the fragment identified it as deriving from a novel alternatively spliced form of LAR containing a retained intron of 85 bp. This intron encodes an additional 13 amino acids followed by an in-frame stop codon, thus its retention is predicted to give rise to a secreted LAR extracellular region isoform(s). LAR transcripts containing the intron were detected by RNase protection assay of colon samples and were present in most human tissues examined by Northern analysis. A protein in colon tumor extract was recognized by antiserum raised to the intron-encoded sequence. Soluble isoforms of the LAR extracellular immunoglobulin (Ig)-like/FN-III repeat-containing region could have a biological function distinct from those isoforms localized at the cell surface and/or coupled to intracellular phosphatase activity.

Endoscopic Nd:YAG laser in the palliative treatment of advanced low rectal carcinoma in Singapore

We used the Nd:YAG laser to palliate symptoms of bleeding and obstruction in 27 cases of rectal carcinoma. Twenty of these patients had advanced inoperable rectal carcinoma, three were at high surgical risk, and four refused surgery. Obstructive symptoms were the main complaint in 10 cases, while 17 patients presented with bleeding. Good palliation of obstructive symptoms was achieved in all obstructive cases with one laser treatment session. However, bleeding tumors required an average of two sessions for complete hemostasis. There were no major complications; minor complications of bleeding after treatment occurred in two patients. Good symptomatic relief was achieved in all cases. The mean survival for all patients was five months. Nd:YAG laser therapy is a safe and efficacious means for palliation of obstructive symptoms and bleeding in advanced rectal carcinoma.

Technical modification to laparoscopic appendectomy

An alternative technique for laparoscopic appendectomy is described. The isolated appendix is exteriorized through the trocar wound, ligated, and resected. The cecum is then returned to the abdomen.