Biomedical subjects

K J Lachapelle

Publications and source records attributed to K J Lachapelle.

3 recordsLinked to original sources

PubMed1995

Benefit of open lung biopsy in patients with respiratory failure.

OBJECTIVE: To determine the benefit of open lung biopsy (OLB) in patients with respiratory failure in whom medical therapy is unsuccessful. DESIGN: A retrospective case series. SETTING: A tertiary care centre. PATIENTS: Thirty-one patients (20 men, 11 women, mean age 55 years) without the human immunodeficiency virus or AIDS who were suffering from respiratory failure. INTERVENTION: OLB through a limited anterior thoracotomy. MAIN OUTCOME MEASURES: Diagnosis, change in therapy, timing of OLB, immune status, survival. RESULTS: A specific diagnosis was made in 68% of patients, and nonspecific pulmonary fibrosis was found in 32%. Eighteen patients (59%) had a change in therapy: 11 had new therapy and 7 had medical therapy withdrawn because of irreversible disease. There was a significant (p = 0.012) improvement in survival in those who had OLB early compared with those who had OLB later in the course of the disease (70% versus 14%). There was a significant (p = 0.026) difference in the proportion of specific diagnoses made among those who had OLB early compared with those who had it later (100% versus 52%). A significant (p = 0.18) improvement in survival was noted in those who had new therapy instituted as a result of early OLB compared with late OLB (86% versus 25%). Patients not immunocompromised before OLB had a significantly (p = 0.02) better survival rate than those who were immunocompromised. CONCLUSIONS: The duration of respiratory failure before OLB and the immune status were associated with improved survival in patients with respiratory failure and unsuccessful medical therapy. This was not directly attributable to changes in therapy after OLB. However, five survived as a direct result of therapy instituted after OLB and seven were spared needless therapy when irreversible disease was found. Overall survival may not be altered by OLB, but individual clinical benefit may be seen in nearly 40% of patients.

Adult↗

PubMed1993

Enhanced revascularization of the ischemic limb by angiogenic therapy.

BACKGROUND: This study tests the efficacy of an angiogenic growth factor, endothelial cell growth factor, in a rabbit model of persistent hindlimb ischemia. METHODS AND RESULTS: Ischemia was induced in the left hindlimb of 22 New Zealand White rabbits by ligation of the distal external iliac artery and complete excision of the common and superficial femoral arteries. Two groups of animals were studied: Group 1 consisted of 11 animals who for 10 days received daily intramuscular injections of 4 mg of endothelial cell growth factor beginning on postoperative day 11, and group 2 consisted of 11 animals who underwent the same surgical ischemic procedure but received only injections of saline daily for the same postoperative period. Perfusion of the ischemic left limb was compared with the normal right limb in each animal on postoperative days 10, 20, 30, and 40 using the calf blood pressure ratio, 99mTc macroaggregate radioisotopic perfusion scans, and serial angiography. Neovascularization in the left thigh at day 40 was quantified from the angiograms. Each technique documented that animals in group 1 had significantly better perfusion than animals in group 2; that is, the calf pressure ratio was higher in group 1 than in group 2 (0.56 versus 0.32 at day 20, 0.64 versus 0.44 at day 30, and 0.70 versus 0.50, P < .0001), and the calf radioisotopic perfusion ratio was also higher in group 1 than in group 2 (0.88 versus 0.74 at day 20, P < .02; 0.93 versus 0.76 at day 30, and 0.96 versus 0.79 at day 40, P < .008). Angiographic studies correlated well with these results demonstrating much earlier distal arterial reconstitution and enhanced neovascularization (23.8 versus 9.0 vessels, P < .007). CONCLUSIONS: The data clearly indicate that an angiogenic growth factor, endothelial cell growth factor, promotes revascularization in this experimental ischemic hindlimb model, raising the possibility that in the future such agents might be of value in humans.

Angiography↗

PubMedDate not supplied

A persistent hindlimb ischemia model in the rabbit.

The study of new approaches for the treatment of limb-threatening ischemia has been hampered by the lack of a suitable animal model of persistent limb ischemia. We describe the development and evaluation of an animal model of persistent hindlimb ischemia, in which ischemia was induced in the left hindlimb of 28 rabbits by ligation of the distal external iliac artery and excision of the common and superficial femoral arteries. The severity of the ischemia and its relief in each animal were evaluated every 10 days postoperatively until day 40 (all animals) or day 90 (five animals). Nine animals developed superficial tissue necrosis in the foot, but no deaths were attributable to the ischemia-inducing procedure. Angiography demonstrated minimal collateralization and sluggish filling of distal vessels up to postoperative day 90. This was accompanied by a decrease at rest in the calf blood flow ratio (p < 0.005 vs day 0), an increase in lactic acid in the femoral venous blood (left vs right side, p < 0.002) up to postoperative day 40, and a decrease in the calf blood pressure ratio (p < 0.0001 vs day 0) up to day 90. Histologic study of the gastrocnemius muscle demonstrated evidence of atrophy and fibrosis in the left hindlimb. This model can be used to evaluate direct and indirect approaches to the treatment of chronic limb ischemia.

Animals↗