Biomedical subjects

F Harford

Publications and source records attributed to F Harford.

4 recordsLinked to original sources

PubMed2006

Does sodium hyaluronate- and carboxymethylcellulose-based bioresorbable membrane (Seprafilm) decrease operative time for loop ileostomy closure?

BACKGROUND: Adhesions can result in serious clinical complications and make ileostomy closure, which is relatively simple procedure into a complicated and prolonged one. The use of sodium hyaluronate and carboxymethyl cellulose membrane (Seprafilm) was proven to significantly reduce the postoperative adhesions at the site of application. The aim of this study was to assess the incidence and severity of adhesions around a loop ileostomy and to analyze the length of time and morbidity for mobilization at the time of ileostomy closure with and without the use of Seprafilm. METHODS: Twenty-nine surgeons from 15 institutions participated in this multicenter prospective randomized study. 191 patients with loop ileostomy construction were randomly assigned to either receive Seprafilm under the midline incision and around the stoma (Group I), only under the midline incision (Group II), or not to receive Seprafilm (Group III). At ileostomy closure, adhesions were quantified and graded; operative morbidity was also measured. RESULTS: All 3 groups were comparable relative to gender, mean age and number of patients with prior operations (26, 25 and 19, respectively). Group II patients were significantly more likely to have pre-existing adhesions than Group III patients (30.6% vs. 14.1%, p = 0.025). At stoma mobilization, significantly more patients in Group III than in Group I had adhesions around the stoma (95.2% vs. 82.3%, p = 0.021). Mean operative times were 27, 25, and 28 minutes, respectively (p = 0.38), with significant differences among sites. There was no significant difference in the number of patients needing myotomy or enterotomy (29, 27 and 24 patients, respectively), nor in the number of postoperative complications (7, 9 and 7 patients, respectively). CONCLUSIONS: When consistently applied, Seprafilm significantly decreased adhesion formation around the stoma but not operative times without any increase in the need for myotomy or enterotomy. These findings were not seen in the overall study population possibly due to the large number of surgeons using a variety of application techniques.

Adjuvants, Immunologic↗

PubMed2000

Intraoperative lower extremity compartment pressures in lithotomy-positioned patients.

PURPOSE: Measurement of anterior leg compartment pressures in eight patients (16 limbs) who were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery. METHODS: Anterior leg compartment pressures were measured in eight patients (16 limbs) by using a slit catheter, whereas subjects were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery. RESULTS: Compartment pressures had minor elevations after initial lithotomy positioning, and gradually increased over time. Levels elevated to 30 mmHg at an average of five (range, 3.5 to 6) hours. The maximum recorded leg compartment pressure was 70 mmHg. The addition of Trendelenburg positioning was noted to consistently increase compartment pressures. All pressures returned to less than 10 mmHg shortly after removing the limb from the stirrups and placing the limb supine. No patients developed clinical evidence of compartment syndrome. CONCLUSIONS: Leg anterior compartment pressures rise when limbs are placed in the lithotomy position for prolonged periods of time. The rise in pressure is increased with the addition of Trendelenburg positioning. Anterior compartment pressures reached a threshold of 30 mmHg at an average of five hours. The results of this study suggest that lithotomy positioning of the lower extremities has the potential to initiate leg compartment syndrome when the period of positioning approaches five hours. Removing the limbs from the stirrups and placing them in the supine position allows the pressure in the compartments to return to normal.

Aged↗

PubMed1997

Modulatory effects of the colonic milieu on neutrophil oxidative burst: a possible pathogenic mechanism of ulcerative colitis.

An important hallmark of ulcerative colitis (UC) is mucosal neutrophil (PMN) infiltration associated with mucosal damage. This suggests that colonic chemoattractants such as bacterial products (e.g., N-formyl-methionyl-leucyl-phenylalanine (fMLP), lipopolysaccharide (LPS)) reach systemic circulation and attract PMNs to the colon. PMNs are then activated in the colonic mucosa and release their toxic oxidative metabolites. However, bacterial products are also present in the systemic circulation of healthy subjects. Thus we hypothesized that PMNs develop tolerance to colonic factors in the normal state and that this tolerance is absent in UC. We evaluated the PMN respiratory burst in response to stimulation with fMLP, LPS, or phorbol 12-myristate 13-acetate (PMA) by measuring the production of reactive oxygen species (ROS) with both luminol-enhanced chemiluminescence and a cytochrome C reduction assay. PMNs were obtained from control subjects, inactive UC patients, patients with UC who had undergone colectomies, and non-UC patients with colectomies. All three stimuli induced a significant rise in ROS. PMNs from non-UC colectomy subjects produced significantly higher ROS than PMNs from control subjects with intact colons in response to both fMLP and LPS. In contrast, PMNs from UC colectomy patients produced levels of ROS similar to those produced by PMNs from UC patients with intact colons in response to fMLP and LPS. Colectomy had no effect on PMA-induced ROS production in controls. The observed difference in fMLP-induced ROS production in control subjects with intact colons was not due to fMLP receptor down-regulation because a competition assay performed with the fMLP blocker BMLP showed a similar receptor apparent affinity in all four groups. We conclude the following: (1) the normal colonic milieu modulates the PMN respiratory burst, resulting in hyporesponsiveness of PMNs to "physiologic" but not "pharmacologic" stimulation. This effect is not due to receptor down-regulation. (2) UC colonic milieu does not appear to modulate PMN respiratory burst. This loss of PMN "tolerance" to colonic factors may have a pathogenic role in the sustained inflammation and tissue damage in UC.

Adult↗

PubMed1982

Carcinoma of the colon and rectum: the natural history reviewed in 1704 patients.

For 1704 patients with large bowel cancer compiled by the Armed Forces Central Medical Registry, selected prognostic factors were related to five-year or longer survival. The majority of late deaths (those occurring after five years) resulted from cancer in the descending colon, sigmoid colon or rectum rather than from cancer in the right or transverse colon. For example, among all patients with cancer of the rectum, 15.4% of those with Dukes' B tumors and 10.9% of those with Dukes' C tumors died of rectal cancer between five and ten years after diagnosis. When late survival rates were compared, patients with right and transverse colon cancer (8 deaths/93 at risk) fared significantly better than those with left colon and rectal cancer (33 deaths/171 at risk; P = 0.01). Among patients with left-sided colon and rectal carcinoma, a further significant difference in late survival was found when stage of disease was considered: patients with Dukes' A cancers (3 deaths/47 at risk after five years) fared better than those with Dukes' C cancers (21 deaths/74 at risk) (P = 0.002). For Dukes' B and C stages of disease, patients with left colon and rectal cancer fared worse than those with right and transverse colon lesions after 60 months. Of all patients who died of large bowel cancer after five years, 69% had a recurrence of cancer by 60 months, and most late recurrences were located in the descending and sigmoid colon and in the rectum. These results show differences in survival after five years with respect to both site of cancer in the colon and stage of initial disease. Our findings indicate that many left-sided large bowel cancers have a slowly progressive natural history.

Adenocarcinoma↗