G. Robert Mason

Photoradiation therapy of head and neck cancer.

We have embarked upon a pilot study of photoradiation therapy (PRT) in the treatment of persistent or recurrent cancer of the head and neck, utilizing the photosensitizing agent, hematoporphyrin derivative (HPD). This treatment is based upon selective concentration of HPD within malignant tissue, with resultant necrosis upon illumination with light of the appropriate wavelength (640 nm). Patients entered in this trial have failed all forms of conventional therapy. Twenty-one patients with local recurrence were treated. Sites of recurrence were: tongue (9); nasopharynx (3); floor of mouth (2); soft palate (2); oropharynx (1); buccal mucosa (1); maxilla (1); larynx (1); and basal cell nevus (1). There were six complete responses and twelve partial responses (greater than 50% reduction). These responses are clinically significant, with some complete responses lasting over 1 year after a single course of therapy. Ten patients with cutaneous metastases from head and neck primary tumors were also treated. There were two complete responses and three partial responses. However, these patients rapidly developed new tumors in areas adjacent to those previously treated. Less than complete responses could be augmented by repeated applications of this technique. The success of this pilot study combined with the accessibility of head and neck primaries suggest that there should be a clinical trial of HPD-PRT in early mucosal cancer of the head and neck region.

Predictability and maintenance of portal flow patterns after small-diameter portacaval H-grafts in man.

Patients undergoing small-diameter (8, 10, 12, and 14 mm) portacaval H-grafts were followed up to 3.5 years. Eight- and 10-mm grafts maintained prograde portal perfusion in 50% of the patients. Follow-up studies performed from 6 to 36 months after surgery show late shunt patency to be 97%. Recurrent variceal hemorrhage has not occurred in any patients. Direction of portal flow after a shunt was related to the size of the portal vein and the size of the shunt. If the shunt diameter was less than 50% that of the portal vein measured on the preoperative angiogram, portal flow was prograde. Encephalopathy rates remained significantly lower in patients with prograde flow after small diameter (8 and 10 mm) portacaval H-graft (p = .0.1). If thrombosis and encephalopathy rates remain low, the small-diameter, polytetrafluoroethylene portacaval H-graft is an attractive alternative to standard portacaval and mesocaval shunts.

Combined treatment of cancer of the esophagus

Abstract Forty patients with carcinoma of the thoracic esophagus were entered into a treatment plan utilizing megavoltage radiation therapy and excision of the entire thoracic esophagus. No patient with advanced primary disease or metastasis to the regional lymphatics benefited from this plan of treatment. Three patients are alive and without disease, nine, thirty-six, and sixty-two months after surgery, respectively.

Computed tomography for localization of parathyroid adenomas.

Fourteen consecutive patients with the clinical diagnosis of primary hyperparathyroidism had computed tomography (CT) preoperatively to evaluate the use of CT in localizing parathyroid adenomas. The patients were scanned from above the level of the thyroid cartilage to the bifurcation of the trachea. Computed tomography correctly identified, prospectively, the site of the adenoma in 7 of 14 patients, including one adenoma that was ectopic in location. Nine of these patients also had barium esophagrams, and this study was accurate in only three of the nine. Our study suggests that CT may be beneficial in the preoperative localization of parathyroid adenomas, particularly those in ectopic locations.

Cysts of the spleen. Report of a case and review of the literature.

Cysts of the spleen are still a rare entity. The present report describes a case of splenic cyst combined with a review of the literature in which classification, clinical manifestations, diagnosis, treatment, and etiology are discussed.

Initial clinical evaluation of carotid artery laser endarterectomy

Clinical study of carotid artery laser endarterectomy began April 15, 1988. This report describes the first 10 cases that were performed in nine patients (five men and four women, mean age 70 years). Indications were asymptomatic stenosis (5), transient ischemic attacks (4), and stroke in evolution (1). There were two emergency cases and eight elective cases (including one reoperative case). Surgical exposure, systemic heparinization, vascular control, and a longitudinal arteriotomy were used. The cleavage plane between atheromas and media was developed with argon ion laser radiation (488 and 514.5 nm) directed through a 300 microns quartz fiber at power 1.0 W. Laser radiation was used to cut the atheromas out of the arteries and weld the end points. Residual atheromatous debris were vaporized with individual laser exposures. Arteriotomies were closed with sutures, and blood flow was restored. The endarterectomies were 3.9 +/- 1.1 cm long and required 330 +/- 97 joules. Mean clamp time was 22.5 +/- 7.9 minutes. Shunts were used in two cases. There were no arterial perforations or injuries as a result of laser light. Complications were hematoma (1), respiratory arrest (1), and transient neurologic deficit (1). Carotid endarterectomy is technically feasible with argon ion laser radiation. In the present series, postoperative observations, averaging 12 months and ranging from 5 to 19 months, have shown satisfactory results. No angiographic follow-up examinations were carried out.

Experimental cholelitholysis with the pulsed tunable dye laser.

This study evaluates the pulsed tunable dye laser with wavelength 504 nm, frequency 10 Hz, and pulse width 1.2 microseconds for cholelitholysis. Power of 10-40 kW was directed through a 250-microns quartz fiber optic to ablate 55 gallstones (removed from 14 patients). The fiber was positioned in direct contact with the stones under saline. Power delivery was begun at 10 kW and increased in 10-kW increments until litholysis began. The range of power and energy necessary to fragment the gallstones was evaluated on four common bile ducts (fresh autopsy specimens). Following fragmentation, all stones were analyzed. There were 35 cholesterol stones (3 calcified) and 20 bilirubin stones (4 calcified). Size ranged from 0.012 to 7.56 cm3 (mean 0.96 +/- 1.41 cm3). Energy necessary for fragmentation ranged from 0.4 to 11.2 J (exposure time 1.0-28 s). Power necessary for fragmentation was 20 kW for 2/55 stones and 40 kW for 53/55 stones. At 40 kW (40 mJ/pulse), common bile duct perforation occurred within 1.1 +/- 0.1 s (0.44 +/- 0.04 J). The pulsed tunable dye laser can fragment gallstones of all compositions. The threshold for fragmentation is 40 kW, but common bile duct perforation occurs at this power. We conclude that laser radiation sufficient to fragment gallstones can injure the common bile duct.

The Inferior Mesenteric Vein as a Conduit for Variceal Decompression: A Preliminary Report

The inferior mesenteric vein — to — renal vein anastomosis with partial gastric devascularization was evaluated in ten cirrhotics. Rebleeding rates were unacceptably high, but when the appropriate indications are used, the operations may be an alternative in a limited number of patients.