Endoscopic monopolar coagulation of internal haemorrhoids: a surgeon's experience of the first 100 cases

AIM

The purpose of this study was to evaluate one surgeon's initial experience with a novel technique of retroflexed endoscopic coagulation of internal haemorrhoids.

METHOD

Patients who presented with symptoms and signs indicating Grade II-III haemorrhoids were counselled before the procedure. Those who were assessed to require an examination of their colon, based on their age and symptoms, underwent a full colonoscopy before treatment of the haemorrhoids. After the procedure, patients were routinely prescribed nonsteroidal anti-inflammatory drugs, antibiotics and laxatives.

RESULTS

The first 100 patients of median age 52.0 (20.8-78.5) years included 65 (65%) women. Five (5%) patients suffered from postprocedural complications, of which three (3%) were postprocedural bleeding and two (2%) were postprocedural pain, all treated conservatively. The recurrence rate was 6% at a median follow-up time of 36 (6-76) months. The median duration of follow-up was 36.5 (8.5-57.0) months.

CONCLUSION

This novel technique appears to be safe and effective for the treatment of Grade II-III internal haemorrhoids, and can be incorporated seamlessly into the end of a colonoscopy for the evaluation of haematochezia. Comparative trials should be performed.

Routine use of setons for the treatment of anal fistulae

AIM

Anal fistula is usually treated by either fistulotomy or fistulectomy. We described the routine use of setons to treat anal fistula without any surgery.

METHOD

Forty-seven consecutive patients with diagnosed anal fistulae were treated using setons alone.

RESULTS

The median age of the patients was 41 (range: 18-70). Of the 47 patients, 15 had surgery previously for fistula and perianal abscess. At least two setons were inserted through each fistula. One was tied tightly to function as a cutting seton and this was sequentially tightened by the patient and another was tied loosely for drainage. Of the 47 patients, 33 (70%) had the placement of setons in the clinic without any anaesthesia. The remaining 14 patients had the setons inserted in the operating room, with one patient having a complex anal fistula and 13 patients having perianal abscess requiring drainage at the same time. There were no post procedure complications in the series. Forty-one patients had completed follow up at clinic within a median duration of 15 weeks (range: two to 67 weeks). The fistula was completely healed by this method in 37 patients (78%). The median healing time was nine weeks (range: four to 62 weeks). One patient developed recurrent fistula and was healed after another seton placement. No patient developed any faecal incontinence and all patients were satisfied with this treatment.

CONCLUSION

The routine seton method is safe, cheap and effective in the treatment of anal fistula regardless of type. It does not leave an open wound and most patients are satisfied with the treatment.

Right-sided colonic diverticular disease as a source of lower gastrointestinal bleeding

Right-sided colonic diverticular disease is a distinct disease entity uncommon in the West. Occasionally, the condition may be complicated by hemorrhage and present as lower gastrointestinal bleeding. We report a series of 25 cases of bleeding right colon diverticulosis and discuss its presentation and management. Patients were selected from the colonoscopic reports of all 190 patients presented with suspected acute lower gastrointestinal bleeding in National University Hospital, Singapore, from 1988 to 1994. Fifty-seven patients (30%) had bleeding diverticulosis in which 25 patients (44%) suffered from right-sided disease. Sixty-four per cent of patients had a history of hypertension. Patients presented with either fresh blood in stools or melena. Fifteen patients (60%) required blood transfusion (median, 2 units). Colonoscopy showed blood clots in the right colon in 15 cases (60%) and active bleeding from the right colon diverticula in 3 patients (12%). The bleeding stopped spontaneously in 16 patients (64%). The other 9 patients required surgery because of continuous or recurrent bleeding. All had a right hemicolectomy performed. The hospital stay was 13 days in this group, compared with 5 days for those undergoing conservative treatment (P = 0.0004). There were no deaths. No patients had further bleeding episodes during a median 7-month follow-up.

Needlescopic or minisite cholecystectomy

Needlescopic or minisite cholecystectomy is laparoscopic cholecystectomy done through tiny ports from 1.4 mm to 3 mm in size. This refinement of conventional laparoscopic cholecystectomy reduces further the invasiveness of the operation and gives an improved cosmetic effect. This series describes the result of 36 needlescopic cholecystectomies done between February 1996 and April 1997. Patients with acute cholecystitis were excluded. There were two conversions to conventional laparoscopic surgery and no conversions to open surgery. Thirty-four patients were successfully treated by this technique. Analgesic consumption and cosmetic result was superior compared to a previous published series of conventionally done cases in the same department.

Management of Mirizzi's syndrome in the laparoscopic era

BACKGROUND

Mirizzi's syndrome is an uncommon cause of common hepatic duct obstruction resulting from gallstone impaction in the cystic duct or gallbladder neck. The role of laparoscopic surgery in the treatment of this condition is still not well defined. This article reports six cases of Mirizzi's syndrome and comments on the management of this condition using the laparoscopic approach.

METHODS

A review of 878 consecutive cholecystectomies from July 1991 to July 1996 identified six cases of Mirizzi's syndrome (0.7%) that were approached laparoscopically.

RESULTS

This study involved three men and three women with mean age of 64 (range, 57-70) years. All cases were approached by laparoscopy. One case was converted because of unclear anatomy in the Calot's triangle due to dense adhesions; open cholecystectomy, exploration of the common bile duct and T-tube insertion was performed. The other five cases were successfully managed laparoscopically. Subtotal cholecystectomy was performed in two cases, and in three patients with cholecystocholedochal fistula, the defect was closed over a T tube. There was no postoperative morbidity or mortality. A follow-up period of 8 to 17 (mean, 12) months revealed no complications.

CONCLUSIONS

Laparoscopic management of Mirizzi's syndrome is feasible and safe but can be technically demanding. A policy of trial dissection by an experienced laparoscopic surgeon is recommended, and if anatomy remains unclear, it is prudent to convert.

Management of Mirizzi's syndrome in the laparoscopic era

BACKGROUND

Mirizzi's syndrome is an uncommon cause of common hepatic duct obstruction resulting from gallstone impaction in the cystic duct or gallbladder neck. The role of laparoscopic surgery in the treatment of this condition is still not well defined. This article reports six cases of Mirizzi's syndrome and comments on the management of this condition using the laparoscopic approach.

METHODS

A review of 878 consecutive cholecystectomies from July 1991 to July 1996 identified six cases of Mirizzi's syndrome (0.7%) that were approached laparoscopically.

RESULTS

This study involved three men and three women with mean age of 64 (range, 57-70) years. All cases were approached by laparoscopy. One case was converted because of unclear anatomy in the Calot's triangle due to dense adhesions; open cholecystectomy, exploration of the common bile duct and T-tube insertion was performed. The other five cases were successfully managed laparoscopically. Subtotal cholecystectomy was performed in two cases, and in three patients with cholecystocholedochal fistula, the defect was closed over a T tube. There was no postoperative morbidity or mortality. A follow-up period of 8 to 17 (mean, 12) months revealed no complications.

CONCLUSIONS

Laparoscopic management of Mirizzi's syndrome is feasible and safe but can be technically demanding. A policy of trial dissection by an experienced laparoscopic surgeon is recommended, and if anatomy remains unclear, it is prudent to convert.

Expression of differential nitric oxide synthase isoforms in human normal gastric mucosa and gastric cancer tissue

The present study investigated the expression and distribution of three isoforms of nitric oxide synthase (NOS) in different anatomical regions of the human stomach and in gastric neoplastic tissues by immunohistochemistry using specific antibodies. Intracellular localization of individual isoenzymes of NOS was detected in normal gastric mucosa. Gastric cancer tissues had a marked reduction of all three NOS isoforms expression. The expression of the endothelial NOS, neuronal NOS and inducible NOS in the tumor tissue was significantly lower than in normal gastric mucosa (P = 0.01, P = 0.02, P < 0.01, respectively). In the tumor tissue the expression of inducible NOS was significantly lower than the expression of both constitutive forms of NOS (P < 0.01). There was a tendency to higher expression of both constitutive forms of NOS in earlier stages T2 of the tumor compared to advanced T4 tumor. In contrast, the expression of inducible NOS was higher than in the advanced T4 tumor than in the earlier stages T2 of the tumor. The mapping of the expression of endothelial NOS, neuronal NOS and inducible NOS in human stomach showed higher expression of NOS isoforms in the distal third than in the proximal third of the stomach (P = 0.03, P = 0.04, P = 0.01, respectively). We conclude that there is greater expression of NOS in the stomach corpus and in antrum than in the proximal third of the normal human stomach mirroring the anatomical predilection of common pathological changes in this part of the human stomach. Furthermore, there was loss of the expression of individual isoenzymes in gastric neoplasms.

A study of the effects of bowel preparation on CEA levels in patients undergoing surveillance colonoscopy

Mechanical bowel preparation has been postulated to be another cause of "false rise' of serum carcinoembryonic antigen (CEA) levels. Furthermore, it was shown that high-risk patients for colorectal cancer had a greater rise in serum CEA after bowel preparation. To verify these findings, a prospective study of 24 consecutive patients in our surgical endoscopic unit on the effect of mechanical bowel preparation of serum CEA level as carried out from January to March 1994. Blood samples were taken before and after bowel preparation for patients undergoing surveillance colonoscopy for various reasons. Our study did not show any relationship between serum CEA levels and bowel preparation. No rise of serum CEA was found even in high-risk patients after bowel preparation.

Intermittent subacute intestinal obstruction due to a giant lipoma of the colon: a case report

A case with intermittent subacute intestinal obstruction due to a giant lipoma of the colon is reported. A 57-year-old woman presented with intermittent pain in the central abdomen and clinical findings of subacute intestinal obstruction. She had had similar symptoms for the last five years. She was diagnosed to have a large polypoid lesion in the ascending colon on barium enema in 1990. However, no surgical treatment was offered to her at that time. At laparotomy, a 16 cm x 11 cm x 11 cm polypoid mass on a 3 cm long stalk in the ascending colon causing colo-colonic intussusception was seen. Subtotal colectomy was performed. Histology showed submucosal colonic lipoma.

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.

Towards a more minimally invasive laparoscopic cholecystectomy--a viewpoint

The advent of laparoscopy and its associated instrumentation in the treatment of gallstone disease heralded a new revolution in surgery. The obvious advantages of cosmetically superior scars and low morbidity have made the minimally invasive approach the preferred choice in the removal of the gallbladder with its stones. Several modifications to the technique have now made it possible to perform cholecystectomy via fewer and smaller port sites. This has translated into even lower postoperative pain and faster recovery times.

Laparoscopic-assisted large bowel resection

Laparoscopic colon resection is a viable alternative to open colectomy. For non-malignant lesions, laparoscopic resection of the affected large bowel is attractive. For malignant lesions, where resection for cure is highly dependent on lymph node clearance, laparoscopic resection has met with criticisms regarding the adequacy of nodal clearance that can be achieved laparoscopically. Several published studies have shown that the operation though technically demanding, does not compromise the extent of resection. We report a series of 43 cases of laparoscopic colon resection done sequentially and successfully from January 1992 to June 1995. The operative time averaged 180 minutes (range 120 to 300 minutes). Five patients developed postoperative complications, which were mainly pulmonary and wound infections. There were no anastomotic leaks or perioperative deaths. The mean hospital stay was 5.3 days (range 4 to 9 days). By the third postoperative day, all patients were feeding and ambulatory. Long-term complications included one small bowel obstruction and one port site recurrence. In our selected group of patients, laparoscopic colon resection has not shown any adverse outcome. Prospective randomised studies are underway in various centres and their preliminary results are favourable.

Randomized trial of periportal peritoneal bupivacaine for pain relief after laparoscopic cholecystectomy

The aim of this study was to determine whether injection of a long-acting local anaesthetic, in relation to the port sites at the level of the parietal peritoneum, would reduce postoperative pain following laparoscopic cholecystectomy. Patients were entered into a randomized, prospective, double-blind study comparing the effects of a standard technique, in which bupivacaine (total of 20 ml, 0.5 per cent) was injected into the subcutaneous periportal tissue around the four port sites, and a technique in which bupivacaine (total of 20 ml, 0.25 per cent) was injected into the subcutaneous periportal tissue as above with the addition of periportal parietal peritoneal injection of bupivacaine (total of 20 ml, 0.25 per cent). Two scores for pain, with the patient at rest, and on movement, were assessed 6 and 18 h after surgery using a visual analogue pain scale. Median pain score was significantly higher in patients who received standard technique (n = 40) than in those given peritoneal injection (n = 40) at both 6 (rest = 3.0 versus 1.0, movement = 5.0 versus 2.9) and 18 h (rest = 1.9 versus 0, movement = 3.2 versus 1.2). Both opiate and oral analgesic requirements were reduced in patients administered peritoneal injection, although this was not statistically significant. The addition of periportal injection of bupivacaine at the level of the parietal peritoneum, performed under direct vision, reduces pain after laparoscopic cholecystectomy.

Differential expression of adenosine A1 receptors in colorectal cancer and related mucosa

Adenosine A1 receptors (A1R) are known to inhibit while the A2 receptors (A2R) stimulate the G-protein cAMP second messenger system and may play a role in cell growth and carcinogenesis. Using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method, mRNA for A1R and A2R was measured in human colorectal adenocarcinomas and individual peritumoural colon tissues. There was differential expression of the mRNA for A1R with tumour tissues having significantly higher amounts compared to peritumoural normal tissues. The mRNA for A2R was not found to be differentially expressed. The increase in the inhibitory A1 receptor in tumour tissues may be in response to increased adenosine release from the hypoxic cells found in malignant tumour tissues, thus indicating a possible role for the adenosine A1 receptor in carcinogenesis.

Nitric oxide synthase activity and expression in human colorectal cancer

The present study investigated the activity and cellular localization of individual isoenzymes of nitric oxide synthase (NOS) using immunohistochemistry and the [3H]citrulline assay in normal colorectal epithelia and neoplastic tissue. Intracellular localization of isoenzymes of NOS was detectable by immunohistochemistry in normal epithelial cells. Colorectal adenocarcinomas had a marked reduction of both Inducible NOS (iNOS) and constitutive NOS (cNOS) expression. Expression of iNOS was completely absent in tumour cells (P < 0.0001), while cNOS was reduced in 66% and absent in 34% of tumours studied when compared with controls (P < 0.0001). NOS activity using the [3H]citrulline assay was detectable in normal epithelium and was found to be reduced in tumours (P < 0.001). In addition, colonic adenomas had reduced INOS but not cNOS expression when compared with controls (P < 0.003 and P = 0.39 respectively). We conclude that NOS is present and active within the epithelium of the normal colon, with localization of the individual isoenzymes. Furthermore, there was loss of activity and expression of individual isoenzymes in colonic neoplasms.

Nitric oxide and cancer

The possibility that the overall process of carcinogenesis may be linked to the deficiency of nitric oxide in a biological cell is examined. A hypothetical model of how this might operate to produce subtle changes in a cell resulting in and/or facilitating carcinogenesis is suggested.

The human leucocyte antigen complex: its role in colorectal cancer

The human leucocyte antigen (HLA) is frequently altered in human tumours compared to the tissue from which they originate. The ability of the tumour to invade requires a change in the phenotype of the cell allowing it to advance and expand without restraint from adjacent tissue and the host immune system. One important regulator of tumour growth is cellular immunity. Antigen recognition by "T" cells occurs in the context of the HLA products. Changes in the HLA expression of a malignant tissue may directly influence immunosurveillance mechanisms, as these molecules play a central role in presenting potentially immunogenic peptides to "T" cells. To assess whether alteration in HLA expression is a critical step in the multistep origin of tumours, it is important to examine the HLA expression in premalignant precursor lesions of tumours and in tumours themselves. Our studies have recently reported a downregulation of HLA class I expression in colorectal cancers and adenomatous polyps when compared to normal appearing mucosa adjacent to the cancer. Our study on the class I antigen expression showed the presence of the antigen on all samples of control colonic epithelium. In sporadic adenomatous polyps of the colorectum, 21% (n = 7) of adenomas expressed levels of HLA that were comparable to controls, 51% (n = 17) expressed low levels, and in 28% (n = 9) the antigen was undetectable. Similarly, in colorectal adenocarcinomas the antigen was reduced even further with levels comparable to controls in 5% (n = 2) of tumours, reduced in 30% (n = 6) and undetectable in 65% (n = 13). This abnormality may result in the loss of immunosurveillance which could be one mechanism by which cancer cells can evade "T" cell control, thus resulting in invasion and metastasis.

Role of oral sodium phosphate and its effectiveness in large bowel preparation for out-patient colonoscopy

The aim of our study was to determine the tolerance and efficacy of oral sodium phosphate compared with polyethylene glycol electrolyte (PEG) solution on out-patient colonoscopy. Seventy-nine patients (35 male, 44 female) for elective out-patient colonoscopy were randomized to receive either PEG (GoLYTELY) solution or oral sodium phosphate (Fleet PhosphoSoda) before the procedure. Patients subsequently completed a questionnaire to assess tolerance to either regimen. The endoscopists, who were blinded to the type of bowel preparation, assessed the results in terms of residual faecal content and percentage of bowel wall visualized. Sixty-seven per cent (26) of 39 patients found Phospho-Soda easy to complete, compared with 53% (21) of 40 patients with PEG (P = 0.06). There was no statistical significance between the two groups in terms of symptomatology. Colonoscopic assessment of the Phospho-Soda group showed better cleansing compared to the PEG group at all levels of the colon (P = 0.02-0.002). Phospho-Soda is just as well tolerated as a standard PEG regimen and provides better cleansing of the bowel for colonoscopy.

Effects of adenosine receptor agonists on nitric oxide release in mouse during endotoxemia

The effects of adenosine receptor agonists on plasma NOx- (NO2- and NO3-) production in mice treated with lipopolysaccharide (LPS) were investigated. NOx- is the stable decomposition product of nitric oxide (NO), which can be measured as a marker of NO production. Injection of the mice with LPS resulted in increased plasma NOx- concentration, reaching a peak after 8 hr (38 times basal level) and then declining slowly. Pretreatment with the adenosine agonists R-phenylisopropyladenosine (R-PIA), 5'-N-ethylcarboxamidoadenosine (NECA), 5'-(N-cyclopropyl)carboxamidoadenosine (CPCA) and N6-cyclohexyladenosine (CHA) 1 hr before LPS administration caused a dose-dependent reduction of plasma NOx- concentration. The rank order of inhibitory potency was NECA > or = R-PIA > CPCA > CHA, which is characteristic of neither A1 nor A2 receptors.

Mutations of the tumour suppressor gene p53 in colorectal and hepatocellular carcinomas

The present study describes mutations of the tumour suppressor gene p53 in a local collection of colorectal and hepatocellular carcinomas (HCCs). Tumour DNA was extracted from both fresh and paraffin-embedded tissues and exons 5-8 of the p53 gene were amplified by polymerase chain reaction (PCR). Mutations were detected by single-strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing. Of the 38 colorectal carcinomas and 42 HCCs examined, 15 (39%) and 13 (31%), respectively, showed p53 mutations. Two-thirds (10/15) of the mutations in colorectal carcinomas were base transitions with a predominance at CpG dinucleotide sites--a pattern characteristic to an endogenous process in cancer development. Three mutational hotspots at codons 175, 248 and 282 were also identified. Mutations did not correlate with histological grade, Dukes stage, or metastasis. However, tumours at the distal site of the colorectum showed a higher proportion of mutations than the proximal site. In the case of HCCs, majority (9/13) of the mutations were base transitions and no mutations were observed at codon 249. This is in contrast to results from other high-incidence areas such as Africa and China, where aflatoxin is believed to be a major aetiologic factor for liver cancers. The results therefore suggest that other risk factors, rather than dietary exposure to aflatoxin, may contribute to the high HCC incidence in Singapore.

Pyloric channel ulcers: management and three-year follow-up

Twenty-five patients with pyloric channel ulcers are presented. They were predominantly males (84%), with a mean age of 54 years. Four patients were operated upon in the initial admission because of gastric outlet obstruction in three and persistent bleeding in one. Twenty-one patients received H2-antagonist treatment (ranitidine 150 mg or cimetidine 400 mg twice a day). Clinical and endoscopic healing rates were 76% and 38% respectively at 6 weeks, and 91% and 85% respectively at 12 weeks of treatment. The recurrence rate at an average of 3 years of follow-up period on maintenance treatment (ranitidine 150 mg or cimetidine 400 mg nightly) was 65%. Three patients were operated upon during the follow-up period due to persistent symptoms in two and recurrence with obstruction in one Surgical procedures were vagotomy + drainage (five patients) and vagotomy + antrectomy (two patients). There were no recurrences in surgically treated patients at an average of 3.5 years of follow-up, and all were graded as Visick I or II.

Combination therapy using adrenaline and heater probe to reduce rebleeding in patients with peptic ulcer haemorrhage: a prospective randomized trial

A prospective randomized trial was performed to assess the efficacy of the combined therapy of endoscopic injection of adrenaline and heater probe application in the management of patients with major peptic ulcer haemorrhage. Some 153 consecutive patients were randomized to receive either local injection of adrenaline (1:10,000) followed by heater probe thermocoagulation (74 patients) or no endoscopic treatment (79 patients). The two groups were well matched with regard to age, haemoglobin concentration on admission, non-steroidal anti-inflammatory drug usage and endoscopic findings. More patients in the treatment group were in shock on admission (21 versus 13). Initial haemostasis was achieved in all patients randomized to endoscopic therapy. Rebleeding occurred in fewer treated than control patients (five versus 16, P = 0.01). The treated group also had fewer deaths (zero versus two) and requirement for operation (two versus six). The results show that the combination of sclerotherapy with adrenaline and subsequent thermocoagulation reduces the rate of rebleeding in peptic ulcer haemorrhage.

Characterization of p53 gene mutations in colorectal carcinomas from an Asian population

A series of colorectal carcinomas from an Asian population in Singapore were analyzed for mutations in the tumor suppressor gene p53. Based on single-strand conformation polymorphism (PCR-SSCP) analysis and direct DNA sequencing, 15 of 38 tumors (39%) were found to contain mutations in exons 5-8 of the p53 gene. The point mutations were predominantly base transitions. Among the 10 transitions, 5 were at CpG dinucleotide sites. One-third (5/15) of the mutations were found at previously identified hotspot codons 175, 248 and 282. In one case, an insertion of a 6-base pair sequence was found. p53 mutations did not correlate with tumor histological grade, Dukes' stage, or metastases. However, tumors at the distal site showed a higher proportion of mutations than the proximal site. Further, no mutation was found in the normal mucosa adjacent to tumor site, suggesting that no germ-line mutations were present. The results were compared with those from other studies and are discussed in connection to possible etiological factors that are specific to the local population.

Laparoscopic cholecystectomy for acute cholecystitis

The safety and efficacy of laparoscopic cholecystectomy for acute cholecystitis were evaluated in a 2-year retrospective review. Results of laparoscopic cholecystectomy in 66 patients with acute inflammation of the gallbladder were compared with those of the standard open procedure for this condition (43 patients) and routine laparoscopic cholecystectomy (227 patients). The laparoscopic procedure for acute cholecystitis was successful in 46 of 66 patients. There was no difference in mean operating time when the inflamed gallbladder was removed laparoscopically or at open surgery (82 versus 84 min); however, each procedure took longer than did routine laparoscopic cholecystectomy (mean 69 min; P < 0.01). There was no difference in analgesic requirement between patients who underwent laparoscopic removal of an acutely inflamed gallbladder and those in the other two groups. Postoperative recovery was significantly faster than that after open surgery (P < 0.01), but took longer than that following routine laparoscopic cholecystectomy (P < 0.01). Inability to identify the cystic duct was the most common reason for conversion to open operation, which occurred in 20 cases of acute cholecystitis. Bile duct injury occurred in one of 66 patients with acute cholecystitis treated laparoscopically, two of 227 cases of routine laparoscopic cholecystectomy but in no patient who underwent open cholecystectomy. In conclusion, laparoscopic cholecystectomy is technically achievable in the majority of patients with acute cholecystitis. The conversion rate is high but, if the procedure is completed successfully, postoperative recovery is more rapid than that after open surgery. However, the method carries a higher incidence of complications and should be attempted only by experienced surgeons.

Aberrant expression of nitric oxide synthase in human polyps, neoplastic colonic mucosa and surrounding peritumoral normal mucosa

The expression of nitric oxide synthase (NOS) was studied by NAD(P)H diaphorase histochemical localization method in (i) individual cells of the normal colonic mucosa (n = 13) which served as control, (ii) colonic polyps (n = 14), (iii) colonic carcinoma (n = 20) and (iv) peritumoral mucosa (2 and 5 or 10 cm away from the tumor). Four of the tumor specimens had normal epithelium adjacent to the cancer, which thus served as an internal control. The expression of NOS activity in colon cancer was significantly reduced as compared to the control group of individuals (P < 0.004); undetectable in 25%, diminished in 45%, normal in 30%. On comparing the expression in normal mucosa and polyps there was a significant reduction of the expression in polyps (P < 0.027); undetectable in 14%, reduced in 35%, normal in 51%. When compared to the peritumoral mucosa at 2 and 10 cm the tumor showed a significant reduction in expression of NOS activity (P < 0.001 and P < 0.0001 respectively). There was no significant difference seen in the expression at 2 and 10 cm (P = 0.329). The peritumoral mucosa at a distance of 2 cm away from the tumor when compared to the control mucosa showed no significant difference (P = 1.000), although there is a tendency to a high normal expression of NOS activity in the mucosa at a distance of 2 cm. Similarly, there was no significant difference between the control mucosa and the peritumoral mucosa obtained at a distance of 10 cm (P = 0.383). The expression of NOS activity in all tissues examined was abolished by preincubation of tissue with the selective NOS inhibitor L-NMMA but not with D-NMMA. Our data showed extensive and significant reduction as identified by the NAD(P)H diaphorase method in the expression of NOS activity, thereby reflecting the activity of nitric oxide in colon cancer and colonic polyps. The generalized suppression of this activity, which precedes the onset of overt neoplasia, may be an important event in colon carcinogenesis. This aberrant expression could also be compatible with the selective advantage to either tumor promotion and metastatic progression or to tumoricidal activity.

Endoscopic sphincterotomy for the treatment of cystic duct leak following laparoscopic cholecystectomy

Two patients who underwent laparoscopic cholecystectomy had postoperative cystic duct leak from slipped metallic clips. One patient presented with biliary ascites and the other with biliocutaneous fistula. Open surgery done in the first patient was not successful in controlling the fistula. Rapid closure of the fistulae was achieved in both cases using endoscopic sphincterotomy.

Randomized controlled trial comparing laparoscopic and open appendicectomy

A study was carried out of 137 patients with a diagnosis of acute appendicitis who were randomized to either laparoscopic or open appendicectomy. Patients found to have perforated or normal appendices at histological examination were excluded. Fifty-two patients undergoing laparoscopic appendicectomy and those receiving 57 open procedures were analysed. Laparoscopic appendicectomy took no longer than the open procedure (mean 43 versus 40 min). The number of doses of pethidine (1 mg per kg body-weight) required in the immediate postoperative period did not differ between the two groups but the mean number of doses of oral analgesic (naproxen sodium 550 mg twice daily) required was less in patients undergoing laparoscopic appendicectomy (2.8 versus 5.0, P < 0.05). There was no significant difference between time to resumption of fluid and diet intake and length of hospital stay. There were five (9 per cent) wound infections after open appendicectomy compared with none after the laparoscopic operation (P < 0.01). Patients who underwent laparoscopy returned to full home (17 versus 30 days, P < 0.01) and social (19 versus 32 days, P < 0.05) activities earlier than those who underwent open operation. Laparoscopic appendicectomy may allow reduction in the number of wound infections and earlier return to normal activities.

Deep vein thrombosis complicating colorectal surgery in the Chinese in Singapore

It has been reported that the risk of thromboembolism after general surgery in Chinese is negligible, thus, prophylaxis has not been used. This study examined the incidence in the high risk subgroup of patients undergoing colorectal operations. In a two-year retrospective review, 35 rectum resections for cancer, 72 colon resections for cancer, and 22 colon resections for benign disease were analysed. The clinical incidence of deep vein thrombosis (DVT) in patients with malignancy was 4.7% (5/107). None of the patients with benign disease had DVT. Three of the five patients with DVT had pulmonary embolism, of which one died. Rectal surgery incurred a higher risk (11.4%) compared to colonic resection (1.4%) (p = 0.038). Postoperative wound infection was an important predisposing factor (p = 0.027). In view of these findings, a prospective trial has been planned to further evaluate the need for prophylaxis in selected high risk patients.

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.

Laparoscopic-assisted right hemicolectomy--a case report

Laparoscopic colon resection has recently attracted attention as a viable option to open colectomy due to its excellent postoperative recovery. We report the first right hemicolectomy done laparoscopically in Asia in a 62-year-old female patient with Dukes-B2 caecal carcinoma. Bowel sounds were present on the first post-operative day (POD) and diet was resumed on the third. The patient was discharged on the fourth POD. There was no complication of anastomotic leakage or wound infection.

Primary repair of iatrogenic colonic perforations in unprepared colon--a report of five cases

Primary repair of iatrogenic colonic perforations sustained during pelvic surgery was successfully undertaken in five consecutive cases who did not receive pre-operative bowel preparation. A proximal diverting colostomy was not performed following the repair. There were no instances of intra-abdominal abscess or colonic fistulation. One case developed wound infection. Post-operative recovery in all cases were mostly uneventful with a mean post-operative ileus of four days and a stay of ten days. Primary repair of iatrogenic colonic perforations in unprepared colon can be safely undertaken without a proximal diverting colostomy with acceptable morbidity.

A rare wandering splenic cyst removed with laparoscopic assistance

This is a report of the first case of a true cyst arising in a wandering spleen. Laparoscopic splenectomy was attempted. The spleen was mobilized under laparoscopic control and the cyst aspirated. Dissection of the pedicle was technically feasible. However, the procedure was aborted due to uncontrollable bleeding from a moderate-sized artery. Although the whole procedure was not completed laparoscopically, laparoscopic assistance facilitated extirpation of the spleen through a 5-cm oblique left iliac fossa incision in a minimally invasive fashion.

Gender and colorectal cancer

Studies of gender differences in colorectal cancer have shown temporal shifts in incidence and site distribution which can be attributed, in part, to environmental and behavioural factors. In high-risk populations, rectal cancer and left-sided colon cancer have been more frequent in older men, whereas right-sided colon cancer has been more commonly found in older women. Among known associations with reduced colorectal cancer risk, women appear to ingest more dietary fibre, seem to benefit more from physical activity and body mass, and consume less alcohol. Although these differences may contribute to the risk differential, hormonal events during reproductive years also appear to affect women's risk at older age. The interactions of sex hormone metabolism and nutrition, including dietary fibre, in colorectal carcinogenesis provide a rewarding field for investigation.

The surgical treatment of multiple small bowel strictures in Crohn's disease by combined resection and stricturoplasty

Crohn's disease is extremely rare among Asians. Resection of strictures causing obstruction has traditionally been the accepted choice in surgical therapy. This may lead to problems such as iatrogenic short bowel syndrome and its sequelae. Stricturoplasty is an acceptable and safe alternative. We report a case where combined stricturoplasty and resection was performed safely and advocate its use.

Laparoscopic cholecystectomy in a patient with empyema of the gallbladder and situs inversus

The successful performance of laparoscopic cholecystectomy in a patient with situs inversus viscerum and empyema of the gallbladder is reported. The 62-year-old man presented with pain in the left upper quadrant associated with fever, chills, nausea and vomiting. The abdomen was tender with guarding and a palpable globular mass in the same region. CT scan demonstrated a distended gallbladder with thick shaggy walls which contained a 2 cm gallstone in the neck and also revealed dextrocardia and situs inversus. The patient's postoperative recovery was uneventful.

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.

The technique of laparoscopic Billroth II gastrectomy

This report describes the technique of totally intra-abdominal Billroth II gastrectomy. Because the procedure is minimally invasive, patient recovery is remarkable compared with the conventional open technique. The development of this procedure completes the minimally invasive revolution in the management of peptic ulcer disease, which began with the introduction of laparoscopic vagotomy.

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 one-half 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.

Loss of colonic HLA antigens in familial adenomatous polyposis

The loss of HLA antigens by neoplastic cells is considered important for tumor growth and metastasis, since it may allow tumors to escape immune surveillance. We studied the expression of HLA class I and II antigens in the colons of 10 patients with familial adenomatous polyposis (FAP), a condition which leads inevitably to colorectal cancer. Expression of HLA class antigens was studied by immunohistochemistry in (a) adenomas from patients with FAP, (b) histologically normal mucosa distant from the adenomas, and (c) histologically normal colonic mucosa from normal subjects. The expression of HLA class I and II antigens was decreased in histologically normal mucosa from FAP patients compared to normal controls. Adenomas showed a similar but quantitatively more pronounced reduction (or loss) of HLA antigen expression. The reduction of HLA expression in adenomas was comparable to that observed in sporadic colon carcinomas. This generalized suppression of HLA gene expression in the colon of FAP patients, which precedes the onset of overt histological manifestations of neoplasia, may be an important early event in colon carcinogenesis.

Clostridial septicemia in an urban hospital

The records of 56 patients at an urban hospital who had positive blood cultures for clostridia were reviewed. Each patient was classified as immunologically normal or immunosuppressed. Data were collected on clinical history, type of clostridial bacteremia, physical and laboratory determinants of infection, therapeutic intervention, clinical course and outcome. Of the 56 patients, 22 were determined to be immunosuppressed. Among all 56 patients, 28 had a malignancy, usually gastrointestinal or hematologic in origin. Fever, leukocytosis and abdominal pain were common in both groups. Clostridial bacteremia almost always heralded clostridial septicemia. A gastrointestinal source of infection, particularly carcinoma of the colon or rectum or enterocolitis, was evident or presumed in 43 of the 56 patients. Clostridium perfringens was the most frequently isolated microorganism, but C. septicum was associated with more complications and a higher mortality rate. Septic complications and mortality were higher among the patients with immunosuppression.