Factors associated with complications of open versus laparoscopic sigmoid resection for diverticulitis.

BACKGROUND: This study critically reviews sigmoid colon resection for diverticulitis comparing open and laparoscopic techniques. METHODS: We conducted a retrospective review of all open and laparoscopic cases of diverticulitis between 1992 and 2001. Data analyzed included the following: indications for operation, postoperative complications, and incidence of laparoscopic conversion to laparotomy. Major and minor complications were analyzed in relation to patients' preoperative diagnosis, age, presence or absence of splenic flexure mobilization, length of stay, and laparoscopic sigmoid resection versus open sigmoid resection. RESULTS: Over a 10-year period, 166 resections for diverticulitis were performed including 126 open cases and 40 laparoscopic cases. No significant differences existed in patient characteristics between the groups. Major complications occurred in 14% of patients, and the laparoscopic conversion rate was 20%. The presence of abscess, fistula, or stricture preoperatively was associated with a higher complication rate only in patients > or =50 years old undergoing open sigmoid resection. The length of stay between patients undergoing laparoscopic resection was significantly less than in patients having open resection. CONCLUSION: Advanced laparoscopic sigmoid resection is an alternative to open sigmoid resection in patients with diverticulitis and its complications. Open sigmoid resection in patients >50 years may have a higher complication rate in complicated diverticulitis when compared with laparoscopic sigmoid resection (all patient ages) and open sigmoid resection (patients <50 years old). Regarding complications, no difference existed between the length of stay in patients with open vs. laparoscopic resection.

Harmonic Scalpel vs. electrocautery hemorrhoidectomy: a prospective evaluation.

INTRODUCTION: Management of posthemorrhoidectomy pain remains a very unsatisfactory clinical dilemma. Compared with electrocautery and laser, the Harmonic Scalpel causes minimal lateral thermal injury during tissue dissection. PURPOSE: The aim of the study was to establish whether decreased lateral thermal injury translated into diminished posthemorrhoidectomy pain. METHODS: A prospective randomized trial comparing Harmonic Scalpel hemorrhoidectomy and electrocautery was undertaken. Fifty consecutive patients were randomized into two groups: Harmonic Scalpels and electrocautery hemorrhoidectomy. The indications included Grade III internal hemorrhoids with external components or Grade IV disease. Patients with additional anorectal pathology (fissure or fistula) were excluded, as were patients with neurologic deficits, chronic pain syndrome, and those already taking narcotic analgesics. Pain was assessed using a visual analog scale preoperatively and on postoperative Days 1, 2, 7, 14, and 28. Twenty-four-hour narcotic usage (Hydrocodone, 10 mg) was recorded on postoperative Days 1, 2, 7, 14, and 28. A three-quadrant modified Ferguson hemorrhoidectomy was performed with each patient in the prone jackknife position. RESULTS: Pain in the Harmonic Scalpel hemorrhoidectomy group was significantly less than in electrocautery patients on each postoperative day studied. Analgesic requirements were also significantly less in the Harmonic Scalpel group on Days 1, 2, 7, and 14. There was no correlation between postoperative pain and grade of hemorrhoid, status of the surgical incision (open vs. closed), or any other study variable. Fifty-five percent of Harmonic Scalpel patients returned to work within one week of surgery, compared with 23 percent of electrocautery patients. CONCLUSION: The study demonstrates significantly reduced postoperative pain after Harmonic Scalpel hemorrhoidectomy compared with electrocautery controls. The diminished postoperative pain in the Harmonic Scalpel group likely results from the avoidance of lateral thermal injury.

Reduction in tissue blood flow in J-shaped pelvic ileal reservoirs.

PURPOSE: This study sought to evaluate tissue blood flow during J-shaped ileal reservoir construction. METHODS: Using laser Doppler flowmetry, tissue blood flow was measured at various locations in J-shaped ileal reservoirs constructed in 10 dogs before pouch-anal anastomosis. For 12 weeks postoperatively, animals were assessed for clinical complications. In another five dogs, tissue blood flow was measured at various stages of J-pouch construction. RESULTS: Tissue blood flow in the reservoir was reduced and was lowest at the "apex" of the "J", the site of clinical stricture in one animal. During reservoir construction, longitudinal enterotomy was associated with the greatest reduction in tissue blood flow. Lowest blood flow in the reservoir was at the site of the intended pouch-anal anastomosis (11.5 +/- 1.6 ml/100 g/min vs. 43.4 +/- 3.4 ml/100 g/min (controls); P < 0.05). CONCLUSIONS: Operative maneuvers of J-shaped ileal reservoir construction, particularly longitudinal enterotomy, significantly reduce tissue perfusion in the involved bowel segment. Tissue blood flow in the pouch is lowest at the site of intended pouch-anal anastomosis, and this may contribute to development of complications seen clinically.

Bile salt inhibition of motility in the isolated perfused rabbit terminal ileum.

The effects of bile on small bowel motility were studied in isolated, perfused rabbit terminal ileum. It was proposed that bile delivery into the distal ileum would inhibit ileal motor activity, by peptide YY (PYY) release and therefore the effect of luminal bile on motor activity was examined and PYY release measured. Luminal bile and taurocheodeoxycholic acid (10 mmol) inhibited ileal motor activity. Arterial infusion of venous effluents from a bile inhibited ileum suppressed motor activity in a second isolated ileum. This shows the presence of a humoral inhibitor of ileal motor activity. Luminal bile increased venous PYY concentrations (42.5 (8.5) to 502 (46.2) pmol/l; p < 0.01) and increased bile salt values (1.7 (0.36) to 88.6 (5.6) 10 mumol/l/l; p < 0.005). Arterial infusion of taurocheodeoxycholic acid at concentrations found in the venous effluent (100 mumol/l/l) suppressed motility (p < 0.001) but infusion of PYY at concentrations in the venous effluent (500.0 pmol/l) failed to inhibit motility. Furthermore, PYY antagonist, PYX 1, failed to reverse the bile induced inhibition of motility. Luminal bile salts inhibit terminal ileal motility and this is independent of PYY release. By slowing motility, bile salts may participate in their own absorption by the 'ileal pump' and in the 'ileal brake' mechanism.

Erythromycin stimulates ileal motility by activation of dihydropyridine-sensitive calcium channels.

Erythromycin, a macrolide antibiotic, is a potent stimulant of small bowel motor activity (MA) which may motility either via the peptide motilin receptor or neural mechanisms. We hypothesized that erythromycin stimulates directly stimulates smooth muscle cells by a calcium-mediated event. Thus, we evaluated the effect of neuronal blockade with tetrodotoxin, muscarinic blockade with atropine, and opiate blockade with naloxone on erythromycin-stimulated MA in isolated perfused segments of rabbit terminal ileum. We also tested the effect of nonspecific calcium channel blockade (verapamil and cadmiun) and specific blockade (dihydroxypyridine and nichol) on erythromycin-stimulated MA. MA was measured with a multichannel continuous perfusion manometry catheter. Erythromycin caused a concentration-dependent increase in MA (ED100 5 x 10(-4) M). Tetrodotoxin, atropine, and naloxone did not effect erythromycin-stimulated MA (P greater than 0.05). Both verapamil (10(-7) M) and cadmium (10(-2)-10(-4) M) inhibited erythromycin-stimulated MA. Selective blockade of "l" type calcium channels using dihydropyridine (10(-6) M) and "t" channels with nickel (10(-2)-10(-4) M) both reversed erythromycin-stimulated MA. Since the isolated segments of terminal ileum were free of exogenous humoral and neural effects, these studies indicated that erythromycin directly stimulated MA in the terminal ileum. Furthermore, since tetrodotoxin, atropine, and naloxone did not inhibit this increase in MA, erythromycin acted by a mechanism which was independent of the intrinsic nervous and opiate systems. In conclusion, these data are consistent with the model that erythromycin stimulates ileal motility by a mechanism involving activation of dihydroxypyridine and nickel-sensitive calcium channels.

Adaptive increase in peptide YY and enteroglucagon after proctocolectomy and pelvic ileal reservoir construction.

Functional results improve with time after proctocolectomy and pelvic ileal reservoir construction. We hypothesized that adaptive increases of circulating and tissue levels of the gut hormones peptide YY (PYY) and enteroglucagon may contribute to this improvement by slowing small bowel transit and increasing small bowel absorption. The specific aim of this study was to measure plasma and ileal mucosal concentrations of PYY and enteroglucagon in dogs 1 year after proctocolectomy and ileal reservoir-anal anastomosis. In the ileal reservoir dogs, postprandial PYY levels reached 238 +/- 31 pmol/liter compared with 93 +/- 33 pmol/liter in sham operated controls (P less than 0.001). Postprandial plasma enteroglucagon levels reached 199 +/- 53 pmol/liter in reservoir animals and 52 +/- 4 pmol/liter in controls (P less than 0.05). Tissue levels of PYY in the mucosa of the ileal reservoirs were 419 +/- 43 pmol/g compared with 133 +/- 23 pmol/g in normal terminal ileum (P less than 0.0001). Enteroglucagon levels were also elevated in reservoir mucosa (193 +/- 21 pmol/g vs. 113 +/- 9 pmol/g in controls, P less than 0.05). These data demonstrate that postprandial and tissue levels of PYY and enteroglucagon increase in dogs 1 year after construction of ileal reservoirs. The adaptive increase in PYY would slow small bowel transit and the increase in enteroglucagon would promote mucosal growth, each contributing to the improved functional results.

The role of tissue ischemia in the pathogenesis of anastomotic stricture.

In a chronic dog model, colocolostomies with intact blood supplies were constructed with the circular stapler. By means of "tight" stapling, an ischemic suture line was induced (suture line blood flow reduced to less than 10% of baseline mucosal blood flow). Under these conditions, only one of 20 anastomoses resulted in stenosis at 1 month. Correctly stapled colocolostomies were then performed in bowels rendered ischemic by removal of all mesenteric arcades for 4 to 6 cm. Mucosal blood flow in such ischemic bowels was reduced to 30% and 16% of control, respectively, and suture line blood flow was as low as that of the tightly stapled anastomoses. Significant stenosis (more than 68% reduction of the lumen) was observed in the group with 6 cm of mesenteric clearance. In no dogs did peritonitis or colonic gangrene develop. Gross and histologic revascularization was evident when dogs were killed at 6 weeks. These findings suggest that it is ischemia of the bowel, rather than ischemia at the suture line itself, that leads to anastomotic stricture. In view of the known susceptibility of the human intestine to ischemia, the model may have overstated the degree of ischemia necessary to produce strictures in clinical practice. Since the induced acute ischemia did not persist in the chronic state, we conclude that it is the adequacy of collateral development that determines the outcome in this model.

Local anaesthesia in inguinal herniorrhaphy: influence of dextran and saline solutions on duration of action of bupivacaine.

Because recent clinical trials have shown that dextran solutions can prolong the local anaesthetic action of 0.25% bupivacaine, a prospective double blind trial was performed in patients (n = 50) undergoing uncomplicated elective inguinal herniorrhaphy under local anaesthesia alone. Patients were randomised prior to infiltration of local anaesthesia into 2 groups: 0.5% bupivacaine (30 ml) diluted with an equal volume of either 0.9% saline or an equal volume of dextran 110. There was no significant difference in duration nor degree of postoperative anaesthesia between the two groups. Dextran solutions were found to be significantly more acidic than saline solutions and the possible effects of this on bupivacaine kinetics are discussed.