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Biomedical subjects

M R Quigley

Publications and source records attributed to M R Quigley.

32 records · Page 2Linked to original sources
PubMed1988

Histology and angiography in a bifurcation aneurysm model.

Laser-sealed arteriotomy has recently been shown to produce a reliable saccular aneurysm model. By applying this method to the rat abdominal aorta and performing serial angiography, the behavior of this aneurysm model at an arterial bifurcation has been studied for the first time. Three days after laser-sealed arteriotomy, no aneurysms were found, but in animals studied 7, 14, 21, and 28 days after laser-sealed arteriotomy, a 100% (17/17) aneurysm formation rate was achieved. Serial angiography did not demonstrate significant changes in size when performed at 2-week intervals, but angiography significantly underestimated true aneurysm size (p less than 0.001) as a function of increasing aneurysm diameter (p less than 0.001). By light-microscopic analysis, these aneurysms were similar to human cerebral saccular aneurysms. This saccular aneurysm model could be used to study various surgical and interventional radiology techniques in experimental animals.

Angiography↗
PubMed1987

Review of tissue welding applications in neurosurgery.

New technical advances have made feasible the utilization of low-powered laser energy for constructive applications. Experience with laser bonding of blood vessels, peripheral nerves, and dura has been obtained. These studies are summarized, and the future potential of laser bonding of tissues of the central nervous system is discussed.

Animals↗
PubMed1987

Laser-assisted end-to-side anastomosis.

The milliwatt CO2 laser was used to anastomose rat carotid arteries in an end-to-side fashion, and this technique was compared to the standard suture technique. Vessels were studied at two to six weeks. All anastomosis were patient and overall, there was a 78.6 percent rate of aneurysm formation in the laser cohort, compared with 7.1 percent with suture (p less than 0.001 Fisher exact). Vessels and aneurysm histology were similar to those previously reported for the end-to-end technique.

Anastomosis, Surgical↗
PubMed1987

Laser-sealed arteriotomy: a reliable aneurysm model.

Laser-assisted vascular anastomosis (LAVA) is associated with a significant aneurysm problem when it is applied to small arteries. The etiology of this phenomenon was investigated by creating arteriotomies of different lengths and orientation in the rat carotid artery and sealing them with the milliwatt CO2 laser. It was found that increasing the arteriotomy length from 0.5 to 1.0 mm significantly raised aneurysm occurrence (4/17 vs. 25/28, chi-square: p less than 0.001) regardless of orientation. Systemic hypertension (systolic blood pressure greater than or equal to 170 mm Hg) also significantly affected the aneurysm rate among the 0.5-mm arteriotomy group, raising aneurysm occurrence from 23.5% (4/17) to 100% (14/14) (p less than 0.001). Assuming that the stay-sutures used for LAVA's act as rigid supports, the rate of aneurysm occurrence must be related to the distance between sutures. This phenomenon has been exploited to create a reliable aneurysm model.

Animals↗
PubMed1987

Bursting pressure of experimental aneurysms.

The laser-sealed arteriotomy (LSA) technique was used to create experimental aneurysms in the rat carotid artery. Animals were reexplored 2, 4, and 8 weeks following LSA, at which time the aneurysms were measured and subjected to a bursting strength pressure. In addition, a group of hypertensive rats with LSA was also tested 2 weeks after surgery. The LSA procedure produced aneurysms of a stable size and bursting pressure over the time studied. The bursting pressure technique may be applicable for assessing aneurysm therapy in an experimental setting.

Animals↗
PubMed1986

Comparison of myointimal hyperplasia in laser-assisted and suture anastomosed arteries. A preliminary report.

Use of the milliwatt CO2 laser to perform microvascular anastomoses is associated with characteristic histologic changes, including intimal hyperplasia and medial necrosis. The extent of myointimal proliferation after both suture and laser-assisted vascular anastomosis was assessed in the rat femoral artery model. At 2 weeks the average intimal height of the laser-anastomosed vessels was 11.7 +/- 2.2 microns (mean +/- standard error of the mean) vs. 21.3 +/- 3.2 microns for sutured arteries (p less than 0.05). By 6 weeks the groups were equivalent (laser, 25.6 +/- 4.6 microns; suture, 17.3 +/- 1.2 microns; p, not significant). The medial changes associated with the laser-assisted method appear to inhibit the proliferative response at 2 weeks but are reversed by 6 weeks.

Animals↗
PubMed1986

Aneurysm formation after low power carbon dioxide laser-assisted vascular anastomosis.

A series of 125 adult rats was operated upon to perform end-to-end anastomosis of the femoral artery using either a carbon dioxide laser or conventional suture technique. Vessels were inspected at varying time intervals grossly and microscopically. Overall, the rate of aneurysm formation for the laser group was 18.6% (21/113). Late aneurysm formation (1 week or longer after operation) was seen in 29.8% (20/67) of the laser group. No aneurysms were noted in the suture group either early or late. Histological examination of the laser-joined vessels revealed widespread necrosis and loss of elastic elements in the media. In time, abnormal spindle-shaped cells appeared in this damaged layer. Histologically, the aneurysms were indistinguishable from those reported in human cerebral aneurysm cases. This technique provides an experimental aneurysm model and lends support to the acquired/degenerative theory of human cerebral aneurysm formation.

Aneurysm↗
PubMed1985

Microvascular anastomosis using the milliwatt CO2 laser.

The milliwatt CO2 laser was used to anastomose small vessels in a rat femoral artery model. The technique requires multiple brief applications of 60-70 mW after placement of three equidistant 10-0 nylon stay sutures. The vessel histology is described immediately and 1, 3, 7, and 21 days after the procedure. The laser effects tissue bonding through changes in the collagen of the adventitia and media. Subsequent healing consists of new collagen deposition in the adventitia and reendothelialization of the intima associated with neointimal proliferation at 3 weeks.

Animals↗
PubMed1985

Fibrinolytic activity following laser-assisted vascular anastomosis.

New technology has allowed tissue bonding to be feasible using carbon dioxide laser energy. Laser-assisted vascular anastomosis (LAVA) has shown comparable patency results with standard suture anastomosis, but LAVA procedures produce thermally induced transmural structural alterations. To assess functional intimal recovery in LAVA versus sutured vessels, a fibrinolytic slide technique was utilized in 21 rats which had LAVA performed in one femoral artery while the opposite limb underwent a conventional microsuture anastomosis. Conventional anastomosis had persistent fibrinolytic activity while LAVA had return of fibrinolytic activity by 48 hours. Intimal fibrinolysis inhibition following LAVA is reversible and this technique does not lead to an increased incidence of thrombosis.

Animals↗
PubMed1985

Comparison of bursting strength between suture- and laser-anastomosed vessels.

The bursting strength of suture- and laser-assisted vascular anastomosis (LAVA) was assessed using a standard rat femoral artery model. Vessels were studied from 1 hour to 3 weeks. LAVA arteries consistently demonstrated lower bursting strengths than those of suture controls, with significant differences at 1 day, 3 days (P less than 0.001), and 1 weeks (P less than 0.01). Return of strength occurred in a pattern reminiscent of wound-healing models. Relatively low bursting strengths at 1 and 3 days in the LAVA cohort may explain the high aneurysm rate reported to complicate this procedure.

Animals↗