Evaluation of four elastomeric interocclusal recording materials

Background: The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semiadjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator.     

Occurrence of tetrodotoxin and paralytic shellfish poison in the Taiwanese crab Lophozozymus pictor

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in all 15 specimens of the xanthid crab Lophozozymus pictor collected from northern Taiwan in 1993. The average toxicity of crab specimens was 921 ± 231 (mean ± S.E.) mouse units. The toxin of crab was partially purified and then identified. It was found that the crab toxin contained TTX and gonyautoxin. The ratio of TTX to gonyautoxin for crab toxin was about 9:1.     

Reoperative Thyroid Surgery

Reoperative thyroid surgery is an uncommon operation associated with a high complication rate. We retrospectively reviewed the data of 115 patients to study the incidence of complications after reoperative thyroid surgery. There were 107 women and 8 men (13.4:1.0) with an average age of 42.8 years (range 18–80 years). The most frequent indication for reoperation was completion thyroidectomy for a carcinoma identified by permanent sections (50 patients, 43.5%). Reoperative surgery was performed on 13 (11.3%) patients with recurrent thyroid cancer. The remaining 52 patients underwent reoperation for recurrent thyrotoxicosis (12 patients, 10.4%), recurrent nodular goiter (28 patients, 24.3%) or recurrent multinodular goiter (12 patients, 10.4%). Seven patients with recurrent nodular goiter and one patient with recurrent thyrotoxicosis underwent total thyroidectomy for the presence of malignancies that were identified by frozen sections. Overall, the interval between the initial and reoperative procedures ranged from 1 day to 33 years (2335 ± 272 days). The length of hospital stay was 5.8 ± 0.5 days. The length of time needed for reoperative thyroid surgery was 122.0 ± 6.2 minutes. There was no 30-day perioperative mortality. The postoperative complications consisted of transient hypoparathyroidism in six patients (5.2%), permanent hypoparathyroidism in two patients (1.7%), transient RLN palsy in 3 patients (2.6%), and permanent recurrent laryngeal nerve palsy in two patients (1.7%). Reoperative thyroid surgery can be performed safely with little morbidity to the patient.     

The role of surgery in the management of unusual complications of transcatheter arterial embolization for hepatocellular carcinoma

Transcatheter arterial embolization (TAE) is accepted to be an effective treatment in both resectable and nonresectable hepatoma, which is very prevalent in Taiwan. Two hundred and twenty-five embolizations of TAE were performed in 137 patients in a 3-year period. Postembolization syndrome developed in the majority of patients. We analyzed these patients to study the nature and incidence of unusual complications and the surgical role in their managment. In our series, unusual complications, which were rarely reported in the literature, included 13 cases (5.8%) of gastroduodenal bleeding, 2 cases (0.9%) of duodenal perforation, 9 cases (4.0%) of acute pancreatitis with 1 case of gangrenous change, 24 cases (10.7%) of gallbladder infarction with 1 case of perforation, 4 cases (1.8%) of delayed formation of gallstones, 3 cases (1.3%) of hyperuricemia, and 2 cases (0.9%) of hepatoma rupture. Ischemic necrosis of the organs may be attributed to the inadvertent blockade of the gastroduodenal artery, gastric artery, cystic artery, and important collaterals. Inadequate superselectivity, the size of the tumor, regurgitation of embolus, anatomical variations, injury of vessel intima, or pseudoaneurysm formation resulting from previous embolization attempts made the avoidance of complications difficult with this technique. Most of the unusual complications could be managed by conservative treatment, but urgent operation was indicated in the cases of organ perforation. Elective operation was also needed for the delayed formation of gallstones with prominent symptoms. Awareness of the occurrence of these untoward sequelae makes us more careful in the evaluation and long-term follow-up of patients following TAE. Surgical intervention plays a selective but important role in the management of these unusual complications.

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Resumen La embolización arterial por cateterismo (EAC) es aceptada como tratamiento efectivo tanto en los hepatomas resecables como en los no resecables, tumores de alta incidencia en Taiwan. Doscientos veinticinco embolizaciones por EAC fueron realizadas en 137 pacientes en un período de 3 años; el síndrome de postembolización se desarrolló en la mayoría de los pacientes. Hemos analizado estos pacientes para estudiar la naturaleza y la incidencia de las complicaciones poco usuales y el papel de la cirugía en su manejo. Las complicaciones poco usuales observadas en nuestra serie, las cuales son raramente informadas en la literatura, incluyen 13 casos (5.8%) de hemorragia gastroduodenal, 2 casos (0.9%) de perforación duodenal, 9 casos (4.0%) de pancreatitis aguda con 1 caso de necrosis gangrenosa, 24 casos (10.7%) de infarto de la vesícula biliar con 1 caso de perforación, 4 casos (1.8%) de formación tardía de cálculos, 3 casos (1.3%) de hiperuricemia, y 2 casos (0.9%) de ruptura del hepatoma. La necrosis isquémica de los órganos puede ser atribuida a la oclusión inadvertida de la arteria gastroduodenal, la arteria gástrica, la arteria cística, y colaterales importantes. Superselectividad inadecuada, tamaño del tumor, regurgitación del émbolo, variaciones anatómicas, lesión de la íntima de la pared vascular, o formación de pseudoaneurismas como consecuencia de intentos previos de embolización hicieron difícil evitar las complicaciones con esta técnica. La mayoría de estas complicaciones poco usuales pudieron ser manejadas con tratamiento conservador, pero la operación de urgencia fue necesaria en casos de perforación de un órgano. La operación electiva también fue necesaria en los casos con formación tardía de cálculos biliares y síntomas prominentes. La toma de conciencia sobre la posibilidad de este tipo de secuelas nos ha hecho aún más cuidadosos en la evaluación y el seguimiento a largo plazo de los pacientes sometidos a EAC. La intervención quirúrgica juega un papel selectivo pero importante en el manejo de estas complicaciones poco usuales.

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Résumé L'embolisation par cathétérisme artériel occupe à Taiwan une place fiable dans le traitement de l'hépatome opérable ou de l'hépatome inopérable. Au cours d'une période de 3 ans 225 embolisations intra-artérielle ont été pratiquées chez 137 malades. Dans la majorité des cas l'embolisation a entrainé des phénomènes secondaires anormaux. Les auteurs font état de complications inhabituelles qui ont été rarement relatées dans la littérature: 13 cas (5.8%) d'hémorragie gastro-duodénale, 2 cas (0.9%) de perforation duodénale, 9 cas (4.0%) de pancréatite aigue dont une avec altérations gangréneuses, 24 cas (10.7%) d'infarcissement de la vésicule dont un avec perforation, 4 cas (1.8%) de formation retardée de calculs vésiculaires, 3 cas (1.3%) d'hyperuricémie, 2 cas (0.9%) de rupture de l'hématome. La nécrose ischémique des organes peut être attribuée à l'obstruction imprévue de l'artère gastro-duodénale, de l'artère gastrique, de l'artère cystique, et d'importantes collatérales. De multiples facteurs peuvent être invoqués pour expliquer les complications indésirables de l'embolisation: cathétérisme hypersélectif inadéquat, volume de la tumeur, régurgitation de l'embolus, blessure de l'intima artérielle, formation pseudoanévrysmale résultant de tentatives antérieures de cathétérisme artériel. La majorité d'entre elles peuvent être traitées médicalement mais l'intervention d'urgence s'impose quand une perforation viscérale est en cause. Il convient également de procéder à la cholécystectomie lorsque la lithiase vésiculaire entraîne des troubles importants. Connaître l'existence possible de ces accidents fâcheux doit rendre circonspect dans l'évaluation exacte de la valeur et le suivi à long terme de l'embolisation. De toute façon l'intervention chirurgicale est indispensable pour traiter certaines complications de l'embolisation.