A. F. P. K. Leong

Lymph node involvement and tumor depth in rectal cancers: An analysis of 805 patients

BACKGROUND: Superficial rectal tumors are said to involve regional lymph nodes rarely. This presumption must be proven beyond any doubt if less radical surgery is to be offered for such patients. PATIENTS AND METHODS: Eight hundred five cases (467 males; median age, 64 (range, 19–97) years) of rectal cancer were reviewed. RESULTS: Lymph node positivity, number of lymph nodes involved, lymphatic vessel, and venous and perineural invasion were significantly increased with increasing depth of invasion of tumor through the bowel wall in univariate analysis. The percentage of lymph node involvement at each tumor depth was as follows: T1, 5.7 percent; T2, 19.6 percent; T3, 65.7 percent; T4, 78.8 percent. Overall lymph node involvement was 59 percent. For patients younger than 45 years of age, the percentage of lymph node involvement was 33.3, 30, 69.3, and 83.3 percent compared with 3.1, 8.4, 64.2, and 78.8 percent for patients aged 45 years or above for T1, T2, T3, and T4, respectively. CONCLUSION: Increased depths of tumor penetration beyond T1 and age less than 45 years have an excessive incidence of lymph node positivity. The finding of lymphatic vessel invasion on biopsy is highly indicative of lymph node metastasis.

Lateral sphincterotomy compared with anal advancement flap for chronic anal fissure.

PURPOSE: This study was designed to assess differences between lateral internal anal sphincterotomy and anal advancement flap for chronic anal fissure. METHODS: Forty patients with chronic anal fissure were prospectively studied. Patients randomized to the sphincterotomy group (n=20; median age, 34 (range, 16–61) years) underwent lateral internal anal sphincterotomy. Patients randomized to the flap group (n=20; median age, 32 (range, 20–44) years) had an anal advancement flap. RESULTS: All fissures in the sphincterotomy group healed following surgery compared with three patients that failed to heal in the flap group (P= 0.12). No patient in either group was incontinent to any degree following surgery. Patient satisfaction with surgery was similar in both groups. CONCLUSION: Anal advancement flap is an alternative to lateral sphincterotomy for chronic anal fissure.

Clinical behavior of complicated right-sided and left-sided diverticulosis

PURPOSE: The aim of the study was to characterize the clinical entity of multiple right-sided (RS) diverticular disease, which is uniquely common in Asians. METHODS: Patients hospitalized with proven diverticular disease from June 1989 to January 1996 were reviewed. Data were retrieved from a prospectively collected computerized database. RESULTS: One hundred eighty consecutive patients were admitted to the Department of Colorectal Surgery, Singapore General Hospital, with multiple diverticular disease. Average age was 65.1 (standard error of the mean, 13.9) years. There were 96 men and 84 women. Women presented, on average, 8.4 years later than men (P< 0.005). Eighty-five patients (47 percent) had massive rectal bleeding, 65 (36 percent) had diverticulitis, 21 (12 percent) had obstructive symptoms, and 9 (15 percent) had enteric fistulas. The diverticula were RS in 76 patients(42 percent), left-sided (LS) in 62 patients (34 percent), and on both sides in 42 patients (24 percent). RS diverticulosis tended to present with massive rectal bleeding (42/76; 55 percent) more often than LS disease (14/62; 23 percent;P<0.005). Surgery for bleeding was also required more often for RS (17/42; 41 percent) than for LS disease (1/14; 7 percent;P<0.05); however, diverticulitis was more common on the left (RS, 25/76, 33 percent; LS, 32/62, 52 percent;P< 0.05). Seventy-eight patients (43 percent) required surgery for these complications of diverticular disease. At a mean follow-up of 15.2 (standard error of the mean, 2) months, mortality was 2 in 78 patients who underwent surgery (3 percent), and morbidity was 15 percent. CONCLUSIONS: In comparison with LS, RS diverticular disease tended to present more often with massive bleeding than with diverticulitis and fistulation. This bleeding was often more severe and required surgical intervention.

Randomized controlled trial of primary fistulotomy with drainage alone for perianal abscesses

PURPOSE: Primary fistulotomy may be advantageous for perianal abscesses because unlike ischiorectal abscesses, fistulas are more commonly found and can be laid open with full preservation of the external anal sphincters. Therefore, a randomized, controlled trial was conducted to compare primary fistulotomy with incision and drainage alone, specifically for perianal abscesses. METHODS: Fifty-two consecutive patients (43 males; mean age, 40 (standard error of mean, 2) years) with perianal abscesses were randomized to treatment by either incision and drainage (controls; N=28) or fistulotomy (N=24). Patients were followed up clinically for a mean of 15.5 (standard error of the mean, 0.7) months. Anorectal manometry was also performed before, six weeks, and three months after surgery. RESULTS: Persistent fistulas developing after surgery were significantly more common after incision and drainage (N=7; 25 percent) than after fistulotomy (N=0;P=0.009). One patient in each group was also found to have a residual abscess, which required repeat drainage. All patients remained fully continent. The anal pressures after incision and drainage and fistulotomy were not significantly different. Operative time, hospital stay, and time for the wound to heal completely were the same in both groups. CONCLUSIONS: Primary fistulotomy at the time of drainage for perianal abscesses results in fewer persistent fistulas and no added risk of fecal incontinence.

Selective total mesorectal excision for rectal cancer

PURPOSE: Total mesorectal excision has been advocated for rectal cancer, but its use in upper rectal and rectosigmoid tumors remains a point of debate. METHODS: One hundred seventeen patients with rectal cancers were subjected to a prospective policy of total mesorectal excision for mid and low rectal cancers and a wide (5 cm) distal margin mesorectal excision for upper rectal and rectosigmoid cancers. RESULTS: Forty-one patients underwent ultralow anterior resection, 10 underwent abdominoperineal excision, 64 had anterior resection and 2 had Hartmanns procedure. The median follow-up was 39 months. Forty-three patients had a defunctioning ileostomy. Three patients (7.3 percent) had anastomotic leaks after ultralow anterior resection with total mesorectal excision. Ninety-three patients had palliative resections. There were four locoregional recurrences in this group, giving an actuarial locoregional recurrence rate of 9.3 percent at five years. The actuarial locoregional recurrence rate after anterior resection was 6.5 percent at five years. The actuarial five-year cancer-specific survival rate was 81.4 percent at five years. CONCLUSION: These results demonstrate that a policy of wide excision of the mesorectum for upper rectal and rectosigmoid cancer and total mesorectal excision for mid and low rectal cancer is associated with a low locoregional recurrence rate and may be as efficacious as routine total mesorectal excision for all rectal cancers.

Randomized, controlled trial of low molecular weight heparin vs. no Deep vein thrombosis prophylaxis for major colon and rectal surgery in Asian patients

PURPOSE: Routine deep venous thrombosis prophylaxis is controversial in Asian patients, because deep venous thrombosis incidence was considered negligible. Because of recent reports of significantly higher incidences, a randomized, controlled trial was conducted to assess the effectiveness and complications of enoxaparin prophylaxis (low molecular weight heparins) in major colorectal surgery. METHODS: Three hundred twenty consecutive patients were randomly assigned to control or low molecular weight heparins groups. Patients in the low molecular weight heparins group were given perioperative enoxaparin starting 12 hours before surgery. The surgeon (blinded) assessed for difficulties related to possible enoxaparin administration. Independent blinded observers performed daily clinical assessments and Doppler studies (at the 3rd and 5th postoperative day). Deep venous thrombosis was confirmed by duplex ultrasound, and pulmonary embolism was confirmed by lung scans or postmortem examinations. RESULTS: Deep venous thrombosis developed in 5 of 169 (3 percent) controls and 0 of 134 low molecular weight heparins patients (P=0.045). Three of the deep venous thrombosis patients had pulmonary embolism, which was fatal in one patient. The surgeons were unable to perceive any increased surgical difficulties in the low molecular weight heparins group. The bleeding-related complications were significantly higher in the low molecular weight heparins patients (controls, n=3 (1.8 percent); low molecular weight heparins, n=9 (6.7 percent)). However, apart from one subdural hematoma and two abdominal hemorrhages needing re-exploration, which also occurred in one of the controls, these complications were minor bruises at the wounds, drains, or injection sites. CONCLUSION: Deep venous thrombosis prophylaxis is needed in Asian patients undergoing major colorectal surgery.

Biofeedback is effective treatment for levator ani syndrome

PURPOSE: The effects of biofeedback (BF) on pain relief and anorectal physiology in patients with levator ani syndrome (LAS) were prospectively studied. METHOD: Sixteen consecutive patients (9 men, 7 women; mean age, 50.1 (range, 39–66) years) with LAS were treated with BF from July 1993 to October 1995. Mean duration of pain was 32.5 (standard error of the mean, 6.7) months. All underwent a full course of BF using a manometric balloon technique. Mean follow-up was 12.8 (standard error of the mean, 2.6) months. Pain score and anorectal physiology tests were administered prospectively by an independent observer before and after BF. RESULTS: After BF, the pain score was significantly improved (before BF: median, 8 (range, 6–10); after BF: median, 2 (range, 1–4);P< 0.02). Analgesic requirements were also significantly reduced (all 16 patients needed nonsteroidal anti-inflammatory drugs (NSAID) before BF; only two patients needed NSAID after BF;P<0.03). There were no significant changes to the anorectal physiology parameters after BF. To date, there have been no side effects or regressions. CONCLUSION: Although BF had a negligible effect on anorectal physiologic measurements in LAS, it was effective in pain relief, with no side effects.

Ambulatory manometry in patients with colonic J-pouch and straight coloanal anastomoses : randomized, controlled trial

PURPOSE: Bowel function after ultralow anterior resection may be improved by a colonic J-pouch. The aim of this study was to compare the bowel function and ambulatory manometry in patients randomly assigned to straight coloanal anastomosis or colonic J-pouch. METHODS: Forty-seven consecutive patients underwent ultralow anterior resection for adenocarcinoma. The colonic J-pouch was constructed with 6-cm limbs. A bowel function questionnaire was administered at one year after surgery. Ambulatory manometry was performed before and at one year after surgery. RESULTS: Values are expressed below as mean and (standard error of the mean). Patients with colonic J-pouch were found to have less frequent stools (4.6 (0.3)vs. 7.1 (0.9) stools/day;P<0.05) and stool clustering (35vs. 63.2 percent;P<0.05) and were less unlikely to soil when passing flatus (85vs. 35.3 percent;P<0.05). The ambulatory anorectal pressure gradient was better preserved in the colonic J-pouch group (30.3 (3.7)vs. 18 (2.6) mmHg;P<0.05). Stool frequency was predicted by the mean rectal pressures (t=3.368;P=0.003). However, higher mean rectal pressures were tolerated by the colonic J-pouch for each daily bowel movement (6.7 (0.6)vs. 4.4 (0.5) mmHg/stool;P=0.008). Anal sampling episodes and slow wave activity were impaired postoperatively in both groups. The minimal anal pressures were lower in patients unable pass flatus without soiling (12.4 (5.3)vs. 26 (2.3) mmHg;P=0.004). Large contraction waves were not seen, and this may be related to the absence of severe defecation problems with 6-cm colonic J-pouches. CONCLUSIONS: A colonic J-pouch resulted in better bowel function and more favorable ambulatory manometric findings at one year of follow-up.

Anal pressures impaired by stapler insertion during colorectal anastomosis: a randomized, controlled trial.

PURPOSE: The significance of anal sphincter injury from transanal inserted staplers was studied. A randomized, controlled comparison was made of anorectal manometry and clinical function after sigmoid colectomy (avoiding nerve injury from rectal mobilization), anastomosed by either transanal inserted stapler or biofragmentable anastomotic ring (avoiding anal manipulation). METHOD: Fifty-eight consecutive patients with sigmoid adenocarcinoma were randomly assigned to transanal inserted stapler or biofragmentable anastomotic ring groups. Anorectal manometry and clinical bowel function assessment were performed by an independent blinded observer before surgery and six weeks and six months after surgery. RESULTS: At six weeks after surgery, there was significant impairment of mean anal resting pressures (mean impairment, 23 percent;P<0.001) and physiologic anal length (mean impairment, 31 percent;P<0.01) in the transanal inserted stapler group (27 completed the trial), but not in the biofragmentable anastomotic ring group (18 completed the trial). Pressures remained impaired at six months. When changes in the anal pressures were compared between groups, the mean anal resting pressure (P<0.001) and maximum squeeze pressure (P<0.01) at six weeks and mean anal resting pressure at six months (P<0.01) were significantly more impaired in the transanal inserted stapler group. Postoperative bowel function was not different between the two groups. Postoperative complications were similar. In the transanal inserted stapler group one patient died of anastomotic leak sepsis and one had wound infection; in the biofragmentable anastomotic ring group one patient died of myocardial infarct and one had wound infection. CONCLUSION: Direct injuries to the internal anal sphincter occurred after transanal inserted stapler but not biofragmentable anastomotic ring anastomoses. Clinical function was not correspondingly affected, probably because of the adequate residual rectal reservoir after sigmoid colectomy.

Performing internal sphincterotomy with other anorectal procedures

PURPOSE: A study was conducted to compare the outcome of combined anorectal procedures involving lateral internal sphincterotomy with lateral internal sphincterotomy alone to determine if the former results in increased complications. METHODS: Complications and anal function of 57 patients who underwent lateral internal sphincterotomy for chronic anal fissure in conjunction with another anorectal procedure (combined group) between April 1989 and June 1992 were compared with 57 other age- and sex-matched patients who underwent lateral internal sphincterotomy alone (control group). RESULTS: There was no statistical difference in the incidence of incontinence in the combined group (8.7 percent) and the control group (7 percent). None of the cases in either group had permanent incontinence. There were also no statistical differences in the incidence of postoperative bleeding, pruritus ani, mucus discharge, abscess formation, fistulation, and rates of fissure recurrence. CONCLUSIONS: Additional anorectal procedures performed at the same time as internal sphincterotomy do not increase the incidence of postoperative complications.