Biomedical subjects

L D Kaelin

Publications and source records attributed to L D Kaelin.

5 recordsLinked to original sources

PubMed1992

In vitro laser recanalization of chronically occluded prosthetic grafts.

Polytetrafluoroethylene (PTFE) and Dacron grafts were implanted in canine femoral and carotid arteries using PTFE and Prolene suture, respectively. Arteries containing occluded grafts were explanted and laser recanalization was attempted in vitro. Laser recanalization was successful in 78% of PTFE grafts compared to 30% of Dacron grafts. Recanalization was complete (residual stenosis less than 5%) in opened PTFE grafts, whereas residual stenosis averaged 60% in recanalized Dacron grafts. PTFE graft/PTFE suture anastomotic tensile strength was unchanged after recanalization, while Dacron graft/Prolene suture anastomotic tensile strength decreased significantly. In addition, anastomotic bursting pressure was significantly higher for lased PTFE grafts with PTFE sutures (300 mg Hg) compared to lased Dacron grafts with Prolene sutures (70 mm Hg). Chronically occluded PTFE grafts with PTFE suture can be safely and effectively opened by laser recanalization. In contrast, attempted laser recanalization of Dacron grafts sutured with Prolene suture is seldom successful, significantly weakens the graft artery anastomosis, and should be avoided.

Anastomosis, Surgical↗

PubMed1992

Routine reimplantation of patent inferior mesenteric arteries limits colon infarction after aortic reconstruction.

Ischemic colitis resulting in colonic infarction after aortic reconstruction is a highly lethal complication. Reimplantation of all patent inferior mesenteric arteries should improve this problem but can be justified only if the procedure is effective and safe. To investigate this, 337 aortic reconstructions done between July 1982 and May 1989 were reviewed. Patent inferior mesenteric arteries had been reimplanted when possible during 151 aortic reconstructions done between April 1986 and May 1989. Before this, patent inferior mesenteric arteries were selectively ligated on the basis of intraoperative bowel inspection, colonic mesenteric Doppler signals, and inferior mesenteric arteries stump pressures during 186 aortic procedures. No patient had colonic infarction as a result of ischemia during the period in which patent inferior mesenteric arteries were reimplanted if possible. In contrast, five patients (2.7%; p less than 0.05) had colonic infarction and perforation during the period of selective inferior mesenteric arteries ligation resulting in four deaths. The operative mortality rate was less during the period of inferior mesenteric arteries reimplantation (4.0% vs 14.5%; p less than 0.05), and transfusion requirements were unchanged. Thus routine reimplantation of patent inferior mesenteric arteries limits colonic infarction and operative deaths after aortic reconstruction.

Aged↗

PubMed1990

Laser recanalization in high risk patients.

Laser recanalization was attempted in 13 patients in whom the risk of surgical therapy was increased by severe angina, infection, absent venous conduit, or recent deep venous thrombosis, and in 4 patients at high risk for limb loss due to severe infrapopliteal arterial occlusive disease. Total occlusions of the superficial femoral, tibial, or peroneal arteries were treated. Recanalization was accomplished using Argon laser power and a Spectraprobe-PLR. Two patients also required common femoral artery endarterectomy to improve inflow. Laser recanalization was successful in 9 patients (53%), and 8 (47%) had relief symptoms. None of the 4 patients with tibial and peroneal artery occlusion had successful recanalization or limb salvage. Restenosis or reocclusion developed in 4 patients during the first year after successful recanalization, but only 1 had recurrent symptoms. Limb salvage was initially achieved in 5 of 8 recanalization failures by surgical reconstruction but 3 developed graft infections requiring graft removal in 2 and amputation in 1. Thus, laser recanalization can accomplish limb salvage in selected patients whose medical or surgical risks complicate arterial bypass surgery.

Adult↗

PubMed1990

The effect of plaque composition on laser recanalization.

Laser recanalization using metal-capped laser fibers and continuous-wave laser energy occurs by thermal ablation of atherosclerotic plaque. Different types of plaque respond differently to laser energy and plaque composition may be an important determinant of the success of laser recanalization. To investigate this hypothesis, 16 patients with symptomatic arterial occlusions in the mid and distal superficial femoral artery underwent B-mode ultrasound arterial imaging prior to attempted argon laser recanalization. The composition of the occlusions was classified as soft (echogenicity less than the adjacent arterial wall), dense (echogenicity equal to the adjacent arterial wall), or calcified (echoreflective). Recanalization was successful in 100% (8/8) of patients with soft occlusions versus 38% (3/8) with dense or calcified occlusions (P = 0.01). Thus, plaque composition as assessed by B-mode ultrasound imaging appears to be an important predictor of the success or failure of arterial recanalization using a thermal laser probe.

Aged↗

PubMed1986

Malignant ascites. Clinical and experimental observations.

Malignant ascites formation is a grave prognostic sign, but palliative efforts seem justified in some patients. Lack of knowledge concerning the natural history of this process hinders the choice of therapeutic options. Over 5 years, 107 patients with untreated malignant ascites were reviewed to define their survival. Pancreas (20), ovary (18), and colon (18) were the most frequent tumors, with 52% of patients presenting with ascites at the time of the initial cancer diagnosis. Cytology evaluation of the ascitic fluid was positive for tumor cells in 57% of cases and a high protein content was noted in 65%. Mean survival of the entire series was only 20 weeks from the time of diagnosis of ascites, with tumors of ovarian and lymphatic origin having better mean survivals of 32 and 58 weeks, respectively. Patients with high ascitic protein levels fared better than those with low levels. In an effort to explain this correlation of elevated protein levels and a favorable survival rate, a hypothesis was proposed that certain tumors secrete a factor, which alters vascular permeability and causes fluid accumulation in the absence of lymphatic obstruction. In an experimental rat model of malignant ascites, the intraperitoneal infusion of cell-free malignant ascitic fluid caused an increase in edema formation and a significant increase in capillary permeability to protein in the omentum. This demonstrated change in the leak of protein explains the formation of ascites by some tumors in the absence of tumor obstruction of the draining lymphatics of the peritoneal cavity and suggests another important mechanism in the genesis of malignant ascites.

Adult↗