During a period of 16 years, 203 proven pancreatic ductal adenocarcinomas were studied. Tumor size was measured on either the resected or the autopsy specimen. Four tumors were smaller than 1 cm, and 17 tumors were between 1.1 and 2 cm. ERCP has been found to be the most accurate in the diagnosis of small pancreatic carcinoma. Followup of 44 patients in whom the tumor was resected showed that survival depended on tumor size. In four patients with tumors smaller than 1 cm without parenchymal invasion, the postoperative 5-yr cumulative survival rate was 100%. Pancreatic carcinoma smaller than 1 cm limited to duct epithelium is considered as early cancer. Various diagnostic imaging modalities are now available to evaluate patients in whom pancreatic carcinoma is clinically suspected. These include ultrasonography (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and angiography. More recently magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and peroral pancreatic ductal biopsy also have been used. This report compares diagnostic modalities for pancreatic carcinoma in order to provide a data base for their rational use in the diagnosis of small resectable pancreatic carcinomas.

Adult↗

PubMedDate not supplied

Glottic closure reflex: control mechanisms.

Reflex glottic closure is a dominant and stable reflex produced by stimulation of the superior laryngeal nerve. Its precise execution is basic to successful sphincteric protection of the lower airway. In exaggerated form, it produces life-threatening laryngospasm. Clearly, reflex glottic closure and laryngospasm are facilitated by: a) expiratory phase; b) decreased arterial partial pressure of carbon dioxide (pCO2); c) increased arterial partial presure of oxygen (pO2); and d) negative intrathoracic pressure. On the other hand, both reflex glottic closure and laryngospasm are inhibited by; a) inspiratory phase; b) increased arterial pCO2; c) decreased arterial pO2; and d) positive intrathoracic pressure. A clear understanding of laryngeal adductor control is an essential first step in the therapeutic modification of abnormal laryngeal closure and laryngospasm.

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PubMedDate not supplied

Vocal cord positioning by selective denervation. Old territory revisited.

Vocal cord positioning produced by selective laryngeal denervation remains a controversial issue in clinical laryngology. Previous studies fail to arrive at uniform conclusions for two important reasons: 1) failure to mark a reference sagittal plane from which to assess the degree of vocal cord lateralization, and 2) failure to recognize the influence of tracheostomy and respiratory positioning of the vocal cords. The present study makes use of photographic and electromyographic documentation in the assessment of the paralyzed cord. Physiologic inactivation of the cricothyroid muscle by tracheostomy is a key determinant of the lateralized cord observed in acute low vagal and recurrent nerve paralysis. Tracheostomy-related cricothyroid inactivation cannot be ignored as a major determinant of cord positioning in paralysis and should not be overlooked in determining the neuroanatomic site of injury.

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