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D A Ahlquist

Publications and source records attributed to D A Ahlquist.

77 records · Page 5Linked to original sources
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Endoscopic gastric vagotomy: a feasibility study using laser in dogs.

The aim of this study was to explore the feasibility of an endoscopic approach to gastric vagotomy using the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser in dogs. Based on gross and histologic measurements, target zones for endoscopic vagotomy were defined with reference to mucosal side landmarks. Target zones containing the unbranched segments of the major intramural vagal branches were linear and symmetrically located anterior and posterior to the midline of the lesser curvature extending from the level of the esophagogastric junction to the proximal antral border. Because of minimal variability between dogs, this zone could be accessed endoscopically and reliably injured. Unfortunately, it was necessary to produce a nearly full thickness burn to interrupt the deep intramural vagal branches. Despite efforts to control dosimetry, delayed perforations occurred in three of four dogs. We conclude that endoscopic gastric vagotomy using the Nd:YAG laser is not feasible in the dog model because of difficulty controlling the depth of thermal injury. An endoscopic approach to vagotomy remains conceptually appealing because of the predictable location of and accessibility to a target zone.

Animals↗
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Endoscopic Nd:YAG laser coagulation of bleeding from radiation proctopathy.

Hematochezia from mucosal vascular lesions usually confined to the rectum represents an uncommon but problematic late complication of pelvic radiotherapy. We studied 47 patients with medically refractory hematochezia resulting from radiation-induced rectosigmoid mucosal vascular lesions. All lesions were endoscopically coagulated with Nd:YAG laser. Median duration of hematochezia before laser therapy was 11 months, despite previous medical treatment (98%) or bypass colostomy (6%). Within 3 to 6 months after laser treatment, the number of patients with daily hematochezia fell from 40 (85%) to 5 (11%; p < 0.001), and the median hemoglobin level increased from 9.7 gm/dl to 11.7 gm/dl (p < 0.001). Complications occurred in three patients (6%); no deaths occurred. The condition in six patients (12.8%) was not improved by laser treatment. Two patients (4%) ultimately required surgical treatment for bleeding control. On the basis of symptomatic, hematologic, and endoscopic responses, Nd:YAG laser photocoagulation controlled bleeding from radiation proctopathy in most patients with an acceptably low morbidity. Patients with sigmoid colon involvement responded less favorably. Endoscopic laser photocoagulation should be considered before surgical intervention for treatment of hematochezia from radiation proctopathy.

Adult↗
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Does performance status influence the outcome of Nd:YAG laser therapy of proximal esophageal tumors?

The value of endoscopic palliative therapy for malignant obstruction in the proximal esophagus has been questioned. To assess the importance of pre-treatment performance status on treatment outcome, we reviewed the records of patients with tumors of the proximal esophagus undergoing endoscopic laser therapy between January 1986 and December 1988. As compared with 10 patients having a good performance status, eight patients with a poor performance status had a lower frequency of obtaining complete functional relief of dysphagia (14% versus 71%), an increased rate of complications (50% versus 0%), and a shorter median survival time (24 days versus 161 days). We conclude that performance status should be considered in determining the appropriateness of laser therapy in patients with proximal esophageal cancer.

Aged↗
PubMedDate not supplied

Stool markers for colorectal cancer screening: future considerations.

Stool screening for colorectal neoplasia has the important advantages of noninvasiveness and affordability over other available screening approaches. However, better markers are needed to improve the sensitivity and specificity of stool screening. A functional classification of stool markers is proposed, based on the mode of luminal marker entry, which may be useful in considering alternative markers.

Antigens, Surface↗