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Biomedical subjects

H T Hoffman

Publications and source records attributed to H T Hoffman.

At least 19 recordsLinked to original sources
PubMed1992

[Free-flap reconstruction of the head and neck].

Free-flap microvascular surgery of the head and neck is now an accepted reconstructive technique. Optimal reconstruction of both function and form are achieved in selected patients by this method. We describe our experience with free-flap reconstruction of head and neck defects in 13 patients. In 5 oncologic patients reconstruction was immediate, while in 8 other oncologic and trauma patients it was delayed. The free rectus abdominis myocutaneous flap was used most often. 3 flaps required revision, but only 1 failed.

Adult↗
PubMed1992

Management of dysphagia in inclusion body myositis.

Inclusion body myositis is an inflammatory myopathy in which dysphagia has been considered a rare finding. However, recent literature finds dysphagia an increasingly common symptom as more cases of inclusion body myositis are identified. Unlike some inflammatory myopathic disorders, inclusion body myositis is resistant to treatment with corticosteroids, and therefore, the otolaryngologist may be consulted regarding surgical options for relief of dysphagia. A patient is described in whom severe progressive dysphagia associated with inclusion body myositis developed. Impaired pharyngeal wall motion and cricopharyngeal achalasia were demonstrated by videofluoroscopic evaluation, and the patient was successfully treated by cricopharyngeal myotomy. The pathophysiologic nature of inclusion body myositis and the mechanisms of cervical dysphagia in the inflammatory myopathies are reviewed.

Aged↗
PubMed1992

Oronasal reconstruction with local mucoperiosteal and free latissimus dorsi flaps.

We describe the use of maxillary sinus mucoperiosteum as a pedicled flap to reconstruct the floor of the nose following resection of cancer involving the palate, buccal mucosa, and mandible. Complete inferior turbinectomy allows access to the roof of the maxillary sinus to harvest the mucoperiosteum as a vascularized flap pedicled under the remaining middle turbinate. A free latissimus dorsi myocutaneous flap suspended from the floor of the orbit and nasal septum is then used to obliterate the maxillary sinus, reconstruct the palate, and support the floor of the nose. A reconstruction employing this combination of flaps is presented, including postoperative endoscopic intranasal photography and magnetic resonance imaging. Despite the elevated level of the floor of the nose and the absence of the inferior turbinates, rhinomanometry performed 3 months postoperatively demonstrates adequate nasal airflow with normal responses to nasal decongestants.

Aged↗
PubMed1992

Syndrome of inappropriate secretion of arginine vasopressin in patients with cancer of the head and neck.

The syndrome of inappropriate secretion of arginine vasopressin (AVP) known as the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is associated with a variety of malignant and nonmalignant diseases. Only 17 cases of SIADH have been reported in the literature in association with cancer isolated to the head and neck. A retrospective review of 1,436 patients with head and neck malignancy excluding skin cancer through The University of Iowa Tumor Registry revealed 60 patients with the diagnosis of either SIADH or hyposmolality. A chart review for each of these patients was then done to establish the diagnosis of SIADH through relevant laboratory values and by excluding other causes of hyposmolality and hyponatremia. In 43 of these patients (3%), SIADH was found to be associated only with the cancer of the head and neck. We conclude that the incidence of SIADH in patients with cancer of the head and neck is much higher than previously recognized. As elevated serum AVP levels may not be clinically apparent unless associated with excessive water ingestation, it is possible that an even higher percentage of patients may have increased serum AVP levels.

Aged↗
PubMed1992

Frontal sinus fractures in the pediatric population.

Full development of the frontal sinus is not achieved until approximately 19 years of age. An evaluation of frontal sinus injuries isolated to the subset of patients less than 20 years old has yet to be reported. In order to determine whether age was a factor in the clinical course of patients with frontal sinus fractures, 209 patients who sustained frontal sinus fractures from January 1985 to April 1990 were identified using the trauma registry from all six major trauma centers, one of which is a pediatric trauma center, in a county of 2.5 million people. Forty patients (19%) were between the ages of 6 and 19 years at the time of their injury. Computed tomography imaging of these pediatric patients identified associated head and neck fractures in 37 (93%) as well as significant central nervous system injury in 22 (55%). Seventeen pediatric patients were treated nonoperatively and 1 died prior to the planned surgery. A detailed analysis of extent of injury and treatment together with a comparison of the 169 adult and the 40 pediatric patients is presented.

Abbreviated Injury Scale↗
PubMed1992

Amyloid of the facial nerve.

Although facial nerve paralysis has been reported in association with amyloidosis, histologic confirmation of facial nerve involvement with amyloid has not been previously demonstrated. A case of localized primary amyloidosis of the facial nerve is presented, and a new magnetic resonance technique for imaging the facial nerve is described.

Aged↗
PubMed1992

MR imaging and HMPAO scintigraphy in conjunction with balloon test occlusion: value in predicting sequelae after permanent carotid occlusion.

OBJECTIVE: Permanent occlusion of the internal carotid artery may be required for en bloc resection of a neck tumor or to treat certain aneurysms. The risk of ischemic infarct is usually assessed with carotid balloon test occlusion and concurrent distal arterial pressure measurement. However, up to 20% of patients who tolerate the test occlusion have delayed neurologic sequelae. We propose enhanced MR imaging and hexamethylpropyleneamine oxime (HMPAO) scintigraphy to detect subclinical signs of ischemia and hypoperfusion as adjuncts to the balloon test occlusion to identify patients at risk for delayed sequelae. SUBJECTS AND METHODS: We prospectively examined 12 patients referred for balloon test occlusion of the carotid artery. Serial measurements of distal occluded internal carotid pressure were recorded. 99mTc-HMPAO was injected IV after 2 min of asymptomatic test occlusion, and single-photon emission computed tomographic (SPECT) data acquisition was done 1-6 hr later. Contrast-enhanced MR imaging was performed 1-8 hr after completion of the 30-min test occlusion. Signs of decreased perfusion or ischemia on these tests were compared with the mean distal arterial pressure and neurologic status of the patient during test occlusion. RESULTS: Seven (58%) of 12 patients had abnormal findings on HMPAO scintigraphy or contrast-enhanced MR imaging. Only one patient had neurologic deficits that corresponded to abnormal MR enhancement. The other 11 patients (92%) remained asymptomatic during the 30-min test occlusion. Of these 11 asymptomatic patients, five (45%) had areas of decreased perfusion on scintigraphy and three (27%) had abnormal MR contrast enhancement suggesting residual focal ischemia as a result of the test occlusion. Mean arterial pressures in the distal occluded artery did not correlate well with the imaging results. CONCLUSION: HMPAO scintigraphy can show clinically silent areas of decreased perfusion, while enhanced MR shows signs of acute ischemia (i.e., significant hypoperfusion) associated with asymptomatic balloon test occlusion. Theoretically, such patients would be at increased risk for permanent sequelae after permanent carotid occlusion.

Adult↗
PubMed1991

Mandible reconstruction with vascularized bone grafts. A histologic evaluation.

To our knowledge, a histologic evaluation of bone healing after mandible reconstruction with vascularized human bone grafts has not been previously reported. Serial sections through both the decalcified graft and the junction between mandible and graft were evaluated in four patients who required surgical removal of their reconstructed mandibles. A failed scapular bone graft that had been wrapped within a pectoralis major myocutaneous flap for salvage following pedicle thrombosis showed markedly resorbed but viable bone with a fibrous union to the native mandible. Viable vascularized grafts without evidence of ongoing resorption characterized an iliac osteocutaneous bone graft and two scapula osteocutaneous grafts that healed with continuity of healthy bone between graft and mandible. Observations from the evaluation of these specimens are made regarding bone circulation, bone union, and bone graft survival as they occur clinically. Implications regarding the techniques of bone plating and indications for use of vascularized bone in mandible reconstruction are discussed.

Bone Transplantation↗
PubMed1991

Arytenoid subluxation: diagnosis and treatment.

Both arytenoid subluxation and recurrent laryngeal nerve paralysis (RLNP) may result from injury to the larynx, and they may be difficult to distinguish clinically. A patient with arytenoid subluxation who was initially believed to have RLNP was treated with medialization laryngoplasty 1 year after the injury. Preoperative magnetic resonance imaging and computed tomography effectively demonstrated the cricoarytenoid subluxation, which was confirmed by intraoperative electromyography (EMG) showing normal electrical activity in the thyroarytenoid muscle. Photographs from preoperative fiberoptic laryngoscopy are presented to identify the appearance of arytenoid subluxation. Computed tomographic findings and photographs from laryngoscopy of two patients with RLNP documented by intraoperative EMG evaluation are presented to help distinguish the clinical appearance of this disorder from arytenoid subluxation. An integrated approach to the diagnosis and treatment of arytenoid subluxation is presented.

Adult↗
PubMed1991

An uncommon case of parotid sialolithiasis.

A vivid example of parotid sialolithiasis diagnosed with an anterior-posterior radiograph and subsequently followed with a superficial parotidectomy is presented. The case presentation is preceded and followed by a discussion of the pathogenesis and treatment of such an abnormality.

Fibrosis↗
PubMed1990

Calcium regulation of antigen expression on normal and malignant human squamous cells in vitro.

In vitro, normal keratinocytes exhibit undifferentiated morphologic features and proliferate for multiple passages in low-calcium medium (less than or equal to 0.3 mmol/L) whereas, in high-calcium medium (greater than or equal to 1.0 mmol/L), these cells assume differentiation characteristics, begin to stratify, and eventually cease proliferating. In contrast, malignant keratinocytes grow well in high-calcium medium. Expression of pemphigus vulgaris antigen, a squamous cell marker, is altered on cultured normal keratinocytes by calcium. In this study we compared the effects of calcium levels on expression of cell surface antigens by UM-SCC-38, a human squamous carcinoma cell line, and normal keratinocytes cultured from newborn foreskin. Pemphigus, pemphigoid, beta 2-microglobulin antigens, as well as the epidermal growth factor receptor and the A9 germinal epithelial cell basement membrane squamous carcinoma antigen were examined. Pemphigus antigen was strongly expressed on normal and malignant cells in high-calcium but not low-calcium medium. Calcium concentration did not affect the expression of any of the other antigens tested. Thus, although calcium induces differentiation and eventual loss of proliferative capacity in normal but not malignant keratinocytes in vitro, we were unable to demonstrate differences in pemphigus vulgaris antigen expression that might be linked to the growth inhibitory effects induced by high calcium levels in nontransformed epithelial cells in culture.

Antigens, Surface↗
PubMed1990

Tracheostoma diverticulum following tracheoesophageal puncture.

Although the initial reports of tracheoesophageal puncture after total laryngectomy reported little to no morbidity, subsequent studies with longer follow-up have reported a significant number of complications. We present the first reported case (to our knowledge) of prolapse of the posterior tracheal wall with diverticulum formation developing 6 years after continuous use of tracheoesophageal puncture speech. Preoperative assessment with a barium esophagogram and rigid esophagoscopy aided in the successful surgical treatment of this disorder. The pathogenesis of this complication and method of repair are discussed.

Diverticulum↗
PubMed1990

Squamous carcinoma of the head and neck in organ transplant recipients: possible role of oncogenic viruses.

A consistently increased incidence of malignancies in renal transplant recipients has been attributed to the effect of chronic immunosuppression required to prevent transplant rejection. Tumors arising in such patients offer a unique opportunity to study the interactions of the immune system and tumor development. A series of three cases of head and neck squamous cell carcinoma arising in patients after renal, cardiac, or bone marrow transplantation are reported. Patient ages at tumor diagnosis were 18, 29, and 53 years, respectively. Time from transplant to diagnosis of tumor ranged from 7 months to 12 years. Only the youngest patient lacked a history of exposure to the traditional pre-disposing factors of tobacco and alcohol use. Histopathologic examination in all three tumors showed features of koilocytosis with hyperkeratosis and parakeratosis suggestive of papillomavirus infection. Squamous carcinoma cells from one of these patients have been successfully established in cell culture. Immune system impairments secondary to the use of antirejection drugs could allow the expression of oncogenic viruses. A recent report of human papillomavirus (HPV) DNA in a primary and metastatic perianal squamous cell carcinoma from a renal transplant recipient, as well as the reported presence of HPV in benign and malignant neoplasms of the upper aerodigestive tract suggests that HPV infection could play a role in the development of squamous carcinomas in transplant recipients. Further studies of HPV infection in cultured cell lines derived from head and neck tumors occurring in immunosuppressed patients are needed to define this relationship.

Adolescent↗
PubMed1990

Chondrosarcoma of the head and neck.

Chondrosarcoma is a malignancy rarely encountered in the head and neck. In an attempt to define this tumor's characteristics and response to therapy, all cases of chondrosarcoma treated at the University of Michigan over the past 25 years were retrospectively studied. Fourteen cases originating in the nose and paranasal sinuses, mandible, temporal bone, and larynx were reviewed. Aggressive surgical resection was the mainstay of treatment, and resulted in an overall survival of 70%, with an average follow-up of 3.5 years. Survival was highest in primary temporal bone lesions, and lowest in paranasal sinus lesions. Unresectable lesions were not cured by other modalities. This study, therefore, continued to support the crucial role of wide surgical resection in the treatment of head and neck chondrosarcoma, but conservative resection, when needed to preserve important structures, has resulted in long-term survival.

Adolescent↗