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Biomedical subjects

J Oba

Publications and source records attributed to J Oba.

22 records · Page 2Linked to original sources

Short-term and long-term results of experimental wrapping techniques for bronchial anastomosis.

Major complications of bronchial anastomoses for either transplantation or sleeve resection include early leak, fistula formation, granulation tissue, and stenosis. To evaluate the impact of technique on these complications, we designed a nonimmunocompromised canine model with a totally ischemic bronchial segment. We wished to discover the prevalence of early and late complications of a telescoping anastomosis and if wrapping techniques modify them. We autotransplanted 25 mm of left main-stem bronchus by telescoping 1 mm of proximal into distal bronchus sutured with interrupted 4-0 polyglactin sutures. The animals were divided into four groups: no wrap; omental pedicle wrap; detached-free omental wrap; and Gelfoam sponge soaked in porcine omental extract. Weekly bronchoscopic studies assessed airway patency. After the animals were put to death at 70 days, the luminal areas of the proximal anastomoses were compared with the origin of the left main bronchus. No air leak, bronchial disruption, or infection occurred in any group at any time. Luminal narrowing occurred in all four groups but was most pronounced in the three groups in which wrapping techniques were used. We conclude that wrapping of a telescoped anastomosis is not necessary to prevent early complications. However, no method completely eliminates stenosis. Further experiments should determine the effects of immunomodulation in this model.

Anastomosis, Surgical↗

Endoscopic thoracic sympathectomy: evaluation of pulsatile laser, non-pulsatile laser, and radiofrequency-generated thermocoagulation.

We describe a modified technique for percutaneous denervation of the thoracic sympathetic chain by laser to treat selected cases of sympathetic causalgia of the upper extremities. The technique involves transpleural ablation with laser under thoracoscopic guidance through the second or third intercostal space-anterior axillary line. We also compare four different modalities of endoscopic denervation: A xenon chloride excimer laser (308 nm, 35 mJ/pulse, 20 pulses/sec, 2.2 mm catheter tip), CO2 laser (14 W, CW, 2 mm spot size), Nd:YAG laser (88 W, CW, 3 mm spot size), and radiofrequency-generated thermocoagulation (3 W, CW, 2.1 mm catheter tip) by performing bilateral thoracic sympathectomy on 12 mongrel dogs (three dogs each). Criteria analyzed included duration of exposure, power density, total energy output, laser penetration and spread, gross morphology, and scanning electron microscopy (SEM) of the destroyed neural tissue. Total ablation of the inferior segment of the stellate ganglion and the T1-T2 nerve roots by excimer laser required 83 +/1 1 Joules over an exposure period of 118 seconds. Ablation by CO2 and Nd:YAG laser required 153 +/- 13 Joules and 554 +/- 47 Joules delivered over 11 and 6 seconds respectively. In contrast, ablation of the same volume of nerve tissue by RF required 810 +/- 50 Joules over 270 seconds. SEM evaluation revealed that excimer and CO2 laser lesions were narrower in configuration compared to RF and Nd:YAG lesions which showed more lateral spread. The actual depth of penetration per 1 second exposure was similar for Excimer and CO2 (1.5 mm) and RF (1.3 mm), but deeper for Nd:YAG (3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗