Covered metal stents for management of inoperable malignant colorectal strictures

BACKGROUND: Metal stents have been reported as an effective alternative to surgery for the palliation of patients with colorectal neoplastic obstruction. Because most of the published series describe the use of uncovered stents, the purpose of our study was to prospectively evaluate the effectiveness, feasibility, safety, and outcome of covered stents for the palliative treatment of malignant colorectal strictures. METHODS: Sixteen patients with advanced distal colorectal cancer underwent placement of 10 and 12 cm long, 23 mm diameter covered stents under fluoroscopic and endoscopic control. Clinical and endoscopic follow-up was scheduled at 3- to 6-week intervals. RESULTS: Stent insertion was successful in 15 of 16 patients (93%). Perforation occurred in one patient during stent placement requiring colostomy. Relief of bowel obstruction was documented in all successfully treated patients. The median follow-up was 21 weeks (range 1 to 46). No recurrence of obstruction was observed during the follow-up period. Stent migration occurred in 2 patients, 7 and 21 days after stent placement. CONCLUSIONS: Covered stents may provide safe and effective palliation of patients with malignant rectosigmoid strictures. Prolonged luminal patency and sealing of fistulous tracts are potential advantages of covered versus uncovered stents in the palliative treatment of colorectal malignancies. ?     

Spasmolytic Effects of Aphanizomenon Flos Aquae (AFA) Extract on the Human Colon Contractility

The blue-green algae Aphanizomenon flos aquae (AFA), rich in beneficial nutrients, exerts various beneficial effects, acting in different organs including the gut. Klamin^® is an AFA extract particularly rich in β-PEA, a trace-amine considered a neuromodulator in the central nervous system. To date, it is not clear if β-PEA exerts a role in the enteric nervous system. The aims of the present study were to investigate the effects induced by Klamin^® on the human distal colon mechanical activity, to analyze the mechanism of action, and to verify a β-PEA involvement. The organ bath technique, RT-PCR, and immunohistochemistry (IHC) were used. Klamin^® reduced, in a concentration-dependent manner, the amplitude of the spontaneous contractions. EPPTB, a trace-amine receptor (TAAR1) antagonist, significantly antagonized the inhibitory effects of both Klamin^® and exogenous β-PEA, suggesting a trace-amine involvement in the Klamin^® effects. Accordingly, AphaMax^®, an AFA extract containing lesser amount of β-PEA, failed to modify colon contractility. Moreover, the Klamin^® effects were abolished by tetrodotoxin, a neural blocker, but not by L-NAME, a nitric oxide-synthase inhibitor. On the contrary methysergide, a serotonin receptor antagonist, significantly antagonized the Klamin^® effects, as well as the contractility reduction induced by 5-HT. The RT-PCR analysis revealed TAAR1 gene expression in the colon and the IHC experiments showed that 5-HT-positive neurons are co-expressed with TAAR1 positive neurons. In conclusion, the results of this study suggest that Klamin^® exerts spasmolytic effects in human colon contractility through β-PEA, that, by activating neural TAAR1, induce serotonin release from serotoninergic neurons of the myenteric plexus.     

The Italian Registry of Therapeutic Apheresis: granulocyte-monocyte apheresis in the treatment of inflammatory bowel disease. A multicentric study

Leukocytes are thought to play an important role in the pathogenesis of inflammatory bowel diseases; granulocyte-monocyte adsorptive (GMA) apheresis, an extracorporeal technique aimed at removing activated circulating leukocytes from the blood, may represent a safe and effective therapeutic tool in these patients. The Italian Registry of Therapeutic Apheresis performed an observational, multicentric study involving 24 Gastroenterology Units. In this study, laboratory data and clinical outcomes of 230 patients (148 males, mean age 43.5 years) affected with ulcerative colitis (UC, n = 194) or Crohn's disease (CD, n = 36) who underwent one or more cycles of GMA were analyzed. Each cycle consisted of five GMA treatments. The patients were followed up for a mean of 8.7 (min. 3 to max. 12) months. At 3 months, positive outcome was achieved in 77.7% of UC patients (72.0% remission, 5.7% clinical response) and 61.3% of CD patients (54.8% remission, 6.5% clinical response). The cumulative proportion of positive outcome at 12 months was 87.1% for UC patients (83.7% remission, 3.4% clinical response) and 77.4% for CD patients (74.2% remission, 3.2% clinical response). No single clinical or laboratory parameter among those analyzed (age, sex, disease characteristics, history of smoking, medication history, baseline values of clinical activity index (CAI)/Crohn's disease activity index (CDAI), hemoglobin, white blood cells count, and erythrocyte sedimentation rate) was independently associated with clinical outcome. The procedure was well tolerated with no significant adverse effects registered.     

Intraoperative laparoscopic liver ultrasonography for staging of colorectal cancer

PURPOSE: This study was undertaken to evaluate the feasibility of intraoperative laparoscopic ultrasonography (ILUS) to completely scan all anatomic segments of the liver through a single port site during laparoscopic resection for colorectal cancer. METHODS: ILUS was performed in patients who were undergoing laparoscopic colorectal cancer surgery using the following approach: 1) presence of a radiologist in the operating room; 2) introduction of the probe through a single cannula site; 3) standardized sequence of four probe positions on liver surface; 4) identification of all major vascular/biliary hepatic structures as a guideline to scan all parenchymal segments of the liver. RESULTS: Twenty-two patients who were undergoing laparoscopic colorectal cancer surgery were prospectively enrolled. Computed tomography (CT) scan films were available for an immediate comparative analysis in the first 12 cases. Mean duration of the procedure was 10 (range, 5–15) minutes. All major vascular and biliary structures were identified in all patients. Sixteen focal abnormalities were identified by ILUS, and ten focal abnormalities were identified by CT scan in the same seven patients. In one patient, detection of a suspected metastasis not seen by preoperative CT scan led to conversion of the surgical procedure to a laparotomy. CONCLUSIONS: ILUS is a safe and expeditious technique that permits scanning of all anatomic liver parenchyma segments through a single cannula site. Because intraoperative palpation of the liver is not possible during laparoscopic colorectal cancer surgery, ILUS should probably be a standard component of the curative laparoscopic colorectal cancer operation.     

High-grade B-cell lymphoma arising in mucosa-associated lymphoid tissue of the duodenum

Duodenal mucosa-associated lymphoid tissue lymphoma is a rare neoplasm. We report a case of a 70-year-old man with non-Hodgkin's lymphoma located in the descending duodenum that was not associated with Helicobacter pylori infection of the stomach. A surgical resection due to obstruction of the bowel lumen above the ligament of Treitz was performed. No invasion into the adjacent structure was confirmed at surgery. The pathological examination showed an infiltration of the duodenal mucosa and submucosa with B lymphocytes. Monoclonal proliferation of the lymphoid tissue was demonstrated by polymerase chain reaction. The histological appearance and the demonstration of monoclonality fulfilled the criteria for malignant high-grade B-cell lymphoma arising from mucosa-associated lymphoid tissue.     

Long-term outcome of patients with perianal Paget's disease

Background: Perianal Paget's disease (PPD) is a rare intraepithelial adenocarcinoma with a significant rate of recurrence after treatment and high risk of progression to an invasive cancer. Patients and Methods: Fourteen patients with a mean follow-up longer than 5 years were studied to determine the outcome after surgical treatment. The immunohistochemical accumulation of p53 protein also was assessed in tissue specimens to evaluate its prognostic role in patients with PPD. Results: Four patients were excluded because of progression to invasive malignancy at the time of diagnosis. Two patients underwent local excision (LE) with macroscopic clearance of the surgical margins; the remaining eight patients underwent wide local excision (WLE), i.e., >1 cm microscopic clearance of the surgical margins. The actuarial 8-year recurrence rate for patients treated with LE and WLE was 100% and 50% (SE=17.7), respectively. Progression to invasive carcinoma occurred after a median time of 56 months (range 23–72) in two patients treated with LE and in one of eight patients treated with WLE. All four patients with recurrence after WLE were successfully treated (no further recurrence) with a second WLE. Actuarial 8-year survival was 0% in the LE group and 40% (SE=21.9) in the WLE group. There was no p53 protein accumulation in any of the ten patients with PPD. Conclusions: Survival of patients with PPD treated by WLE was higher than that for those treated with LE. Thus, wide local excision is recommended over limited local excision as a preferred treatment for PPD. Follow-up longer than 5 years seems to be indicated because of the risk of late progression to invasive cancer. When PPD does recur, a second WLE may be curative. The absence of accumulated p53 protein suggests that this marker may not have a prognostic role in PPD. Presented at the 49th Annual Cancer Symposium of The Society of Surgical Oncology, Atlanta, Georgia, March 21–24, 1996.     

Stimulation of 5‐HT1A receptors in the dorsal raphe reverses the impairment of spatial learning caused by intrahippocampal scopolamine in rats

This study investigated the effect of stimulating 5-HT_1A receptors in the dorsal raphe on the impairment of learning caused by 4 μg/μL scopolamine injected in the CA1 region of the dorsal hippocampus in rats performing a two-platform spatial discrimination task. At 1 (but not 0.2) μg/0.5 μL administered in the dorsal raphe on each acquisition training day 5 min before bilateral intrahippocampal injection of 4 μg/μL scopolamine, 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), a 5-HT_1A receptor agonist, had no effect on choice accuracy and latency or errors of omission but completely antagonized the impairment of choice accuracy by intrahippocampal scopolamine. Administered into the dorsal raphe at 0.2 and 1 μg/0.5 μL, WAY 100635, a 5-HT_1A receptor antagonist, had no effect on rats’ performance or on the impairment caused by intrahippocampal scopolamine but dose-dependently antagonized the effect of 1 μg/0.5 μL 8-OH-DPAT on the scopolamine-induced deficit. The results show that stimulation of presynaptic 5-HT_1A receptors in the dorsal raphe reverses the deficit caused by intrahippocampal scopolamine, probably by facilitating the transfer of facilitatory information from the entorhinal cortex to the hippocampus. Together with a previous study showing that blockade of postsynaptic hippocampal 5-HT_1A receptors antagonized the effect of intrahippocampal scopolamine in the two-platform spatial discrimination task ( Carli et al. 1995b ), the results suggest that drugs with presynaptic stimulatory and postsynaptic blocking actions on 5-HT_1A receptors, such as partial agonists at these receptors, may be useful in the symptomatic treatment of human memory disturbances associated with loss of cholinergic innervation to the hippocampus.     

Right colonic arterial anatomy

PURPOSE: Hemorrhagic complications can be a major cause of conversion and/or morbidity during laparoscopic intestinal surgery. The limited exposure currently provided in laparoscopic intestinal resection demands a precise knowledge of mesenteric vascular anatomy to avoid such complications and to expedite the procedure. Most surgical texts depict a normal pattern of arterial supply to the right colon consisting of three arterial branches (ileocolic artery, right colic artery, and middle colic artery) arising independently from the superior mesenteric artery (SMA). Based on previous reports and clinical observations, we hypothesized that the right colic artery arises infrequently from the SMA, and most commonly, there are only two colonic arteries arising independently from the SMA. METHODS: We performed detailed dissections of the SMA in 56 human cadavers. RESULTS: We found the ileocolic artery in all of our cases and the middle colic artery in 55 of 56 cadavers but only six cases of a right colic artery emanating directly from SMA. CONCLUSIONS: Our data, combined with review of published anatomic studies, lead us to conclude that in the vast majority of cases there are only two independent branches arising from SMA that supply the large intestine, the ileocolic and the middle colic arteries. The right colic artery directly arising from SMA is unusual (10.7 percent). This knowledge may help lower the risk of vascular complications during laparoscopic intestinal surgery.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Montreal, Quebec, Canada, May 7 to 12, 1995.