Biomedical subjects

Frank M Warren

Publications and source records attributed to Frank M Warren.

7 recordsLinked to original sources

PubMed2006

Magnetic resonance appearance of the inner ear after hearing-preservation surgery.

OBJECTIVE: To determine whether the appearance of the inner ear on T2-weighted follow-up magnetic resonance imaging correlates with hearing status after hearing-preservation surgery for vestibular schwannoma. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral medical center. PATIENTS: The study includes patients undergoing hearing-preservation surgery for vestibular schwannoma from 1998 to 2003. INTERVENTION: Diagnostic evaluation with magnetic resonance imaging and audiometric evaluation. MAIN OUTCOME MEASURES: Hearing results as reported in charts was correlated with appearance of membranous labyrinth on T2-weighted magnetic resonance images obtained at least 1 year after surgery. RESULTS: Twenty-nine patients were identified, 16 of whom satisfied the inclusion criteria. All 16 of the patients underwent middle fossa removal of vestibular schwannoma. Serviceable hearing according to American Academy of Otolaryngology-Head and Neck Surgery criteria was preserved in eight patients (50%). Of the eight patients without serviceable hearing, six had the cochlear nerve sacrificed at the time of surgery. All patients with serviceable hearing had normal appearing cochleovestibular signal on T2-weighted images, whereas six of eight patients (75%) with no hearing or poor hearing had abnormal low signal in the inner ear, suggesting inner ear ossification. The positive predictive value of a normal labyrinth for preserved hearing was 90%, whereas the negative predictive value of an abnormal labyrinth for no hearing was 100%. All but one patient who had the cochlear nerve sacrificed showed abnormal morphology of the labyrinth on T2-weighted magnetic resonance imaging. CONCLUSION: We describe the T2-weighted magnetic resonance findings after hearing-preservation surgery for acoustic tumor removal. Loss of inner ear signal on T2-weighted images correlates with loss of hearing postoperatively, whereas preserved inner ear signal correlates with hearing preservation after middle fossa surgery for vestibular schwannoma removal.

Auditory Threshold↗

PubMed2006

Revision lateral skull base surgery.

OBJECTIVE: To describe functional and reconstructive results after revision lateral skull base surgery with comparison of benign and malignant lesions. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: All patients undergoing revision surgery for benign and malignant lateral skull base tumors. INTERVENTIONS: Surgical resection of recurrent lateral skull base tumors and reconstruction of resulting defects. MAIN OUTCOME MEASURES: Cranial nerve function postoperative complications. RESULTS: Forty operations for recurrent lateral skull base tumors occurred between January 1, 1987, and December 31, 2003, with follow-up of at least 1 year. Thirty-three operations were for benign lesions, 27 of which were glomus tumors. Seven operations were for malignant tumors. Fifty-eight percent of patients had preoperative cranial nerve deficits (66% of benign tumors and 14% of malignancies). The most common preoperative deficit occurred in the Xth cranial nerve. Postoperative cranial nerve deficits were seen in 95% of patients and multiple nerve deficits were seen in 75%. The most common postoperative deficits were observed in the IXth and Xth cranial nerves. Thirty-one patients had one previous procedure, six had two previous procedures, and three had three previous procedures. Abdominal fat and temporoparietal fascia were the most common reconstruction materials. There was one case of meningitis, two cerebrospinal fluid leaks, and one pseudomeningocele. There was one recurrent adenoid cystic tumor resulting in death and two partially resected glomus tumors. Subsequent procedures are discussed. CONCLUSION: Postoperative cranial deficits are more common after revision skull base surgery than after primary surgery. Complete resection without recurrence can be expected for revision skull base surgery. Modern reconstruction techniques reduce major postoperative complications and morbidity from cranial nerve deficits.

Adolescent↗

PubMed2005

Neurotologic management of intracranial epidermoid tumors.

OBJECTIVES: Epidermoid cysts are the most common intracranial embryonal tumor, although they account for only 1% of all intracranial tumors. Epidermoids often spread into several intracranial compartments. Thorough preoperative surgical planning is imperative for safe epidermoid removal. This paper discusses the neurotologic management of intracranial epidermoid cysts STUDY DESIGN: Retrospective chart review. METHODS: A database search revealed 10 patients with diagnosis of intracranial epidermoid cysts between January 1, 1971 and December 31, 2003 at our institution. RESULTS: Six males and four females with ages ranging from 18 to 54 years of age underwent surgery between September 1, 1971 and November 4, 2003. The average tumor size was 3.9 cm; six originated in the cerebellopontine angle and four in the petrous apex. Six patients had a translabyrinthine approach to the tumor, two with additional transcochlear exposure. Two patients had tumors removed by way of the middle fossa approach and one through the suboccipital approach. Multiple cranial nerves were involved by tumor in all patients, including nerves III through XI. The internal carotid artery was involved by tumor in four patients. Multiple cranial nerve deficits were seen preoperatively, and facial weakness was the most common new deficit postoperatively. Eight patients required intradural access for complete tumor removal. Seven had complete tumor removal. Headaches were the most common complication. One patient had seizures postoperatively, and another had a malignant epidermoid, which resulted in death. CONCLUSIONS: Intracranial epidermoid cysts require complex surgical planning. They involve multiple cranial nerves and vascular structures. Complete resection is frequently possible with minimal new cranial nerve deficits.

Adolescent↗

PubMed2005

Management of brain herniation and cerebrospinal fluid leak in revision chronic ear surgery.

OBJECTIVES/HYPOTHESIS: Brain herniation and cerebrospinal fluid (CSF) leakage into the middle ear and mastoid are rare but described complications of chronic ear disease. This paper will discuss the presentation and management of brain herniation and/or CSF leak encountered in revision chronic ear surgery. STUDY DESIGN: Retrospective chart review. METHODS: Twelve of 1,130 cases of revision chronic ear surgery in which brain herniation or CSF leak was diagnosed were identified and analyzed. RESULTS: Ten (83%) patients' initial diagnosis was tympanic membrane (TM) perforation with cholesteatoma and two (17%) with TM perforation without cholesteatoma. Initial revision procedures included one (8.3%) tympanoplasty with canal-wall-up mastoidectomy maintaining ossicular continuity, two (17%) tympanoplasties with canal-wall-down (CWD) mastoidectomies with ossicular chain reconstruction (OCR), and nine (75%) tympanoplasties with CWD mastoidectomies without OCR. Three (25%) required a second procedure, two (17%) a third, and one (8.3%) a fourth, finally resulting in four (33%) with an ossicular reconstruction and eight (67%) without. Brain herniation and/or CSF leak were repaired by way of transmastoid and middle fossa approaches. Preoperative and postoperative pure-tone average air-bone gaps were statistically similar (33.1 and 28.1 dbHL, respectively; P = .464). CONCLUSIONS: Brain herniation and/or CSF leak appear to be rare complications of surgery for revision chronic ear disease. Their management require adherence to the principles of establishing a safe ear with hearing restoration as a secondary goal.

Adult↗

PubMed2004

Perioperative parathyroid hormone levels in thyroid surgery: preliminary report.

OBJECTIVES/HYPOTHESIS: An immediate method of accurately predicting postoperative hypocalcemia after total thyroidectomy would allow for selective early discharge of patients at low risk. The objective of the study was to determine the utility of perioperative parathyroid hormone measurement in predicting postoperative hypocalcemia after a thyroid surgery that places total parathyroid function at risk. STUDY DESIGN: Prospective case series. METHODS: Twenty-seven patients undergoing total or completion thyroidectomy had three blood samples drawn for parathyroid hormone measurement before dissection, 10 minutes after specimen removal, and in the recovery room. Serial ionized calcium levels were measured in the postoperative period. Preoperative, postresection, and recovery room levels were compared with postoperative ionized calcium levels. RESULTS: The average values before resection, after resection, and in the recovery room were 69.3 (range, 13-163), 42.3 (range, 0-120), and 37.4 (range 7-79) pg/mL, respectively. The incidence of hypocalcemia was 11% (3 of 27 patients). The rate of hypocalcemia was significantly higher (50%) in patients with recovery room parathyroid hormone values of 10 pg/mL or less relative to patients with recovery room parathyroid hormone values greater than 10 pg/mL (4%) in this setting (P =.01). Among patients with a parathyroid hormone value of less than 15 pg/mL in the recovery room, an increasing parathyroid hormone level in the recovery room relative to the level after resection predicted normocalcemia without calcium supplementation on chi analysis (P =.01). CONCLUSION: The study demonstrated that perioperative parathyroid hormone values can help predict patients who are at highest risk for postoperative hypocalcemia after thyroid surgery.

Calcium↗

PubMed2002

Management of carotid 'blowout' with endovascular stent grafts.

OBJECTIVES/HYPOTHESIS: Since 1992, endovascular techniques for vascular occlusion and stenting have evolved significantly. Endovascular occlusion of the carotid artery has been used in the management of carotid "blowout." Although it seems logical to expand this application to the use of arterial stents to repair rather than occlude the artery when cerebral cross-circulation is inadequate, concerns remain regarding the placement of a foreign body in a contaminated field. The purpose of the present report is to describe our experience with endovascular stents for control of carotid hemorrhage. STUDY DESIGN: Retrospective case review. METHODS: Retrospective review of three cases of acute or threatened carotid hemorrhage managed with endovascular stent placement. RESULTS: Two patients presented with acute carotid blowout, and one patient with a probable sentinel bleed. All patients previously had been heavily treated with surgery and irradiation: Two had developed pharyngocutaneous fistulas, and one had an open wound filled with tumor that surrounded the carotid artery. All were thought to be at significant risk for stroke if the carotid artery was occluded. In all three patients, stent placement resolved the acute hemorrhage. Mean duration of follow-up was 8.3 months. In two patients, the stent became exposed, ultimately thrombosed or extruded, or both. The third patient had no residual sequelae of stenting but died 3 months later. CONCLUSION: When an unacceptable risk of cardiovascular accident makes occlusion unwise, acute carotid hemorrhage can be successfully managed with directed placement of endovascular stents, but the long-term sequelae of placing these foreign bodies in a field with ongoing contamination make this a temporizing rather than permanent measure for use while more definitive long-term solutions are pursued.

Acute Disease↗

PubMed2002

Intraoperative parathyroid hormone levels in thyroid and parathyroid surgery.

OBJECTIVE: To determine the utility of intraoperative parathyroid hormone measurement in predicting postoperative hypocalcemia after thyroid and parathyroid surgeries that places total parathyroid function at risk. STUDY DESIGN: Retrospective case review. METHODS: The case records of 23 patients undergoing total or completion thyroidectomy and 30 patients undergoing parathyroid exploration were reviewed. All patients had intraoperative parathyroid hormone levels measured. Samples were taken before dissection and 10 minutes after the resection was completed. Serial ionized calcium levels were measured in the postoperative period. Percentages of reduction in PTH levels from preoperative to postresection levels were calculated. Percentages of reduction in PTH level and the absolute value of the intraoperative PTH values were compared with postoperative ionized calcium levels. RESULTS: In the 23 patients who underwent thyroid surgery, the average preoperative and postoperative PTH values were 50 pg/mL (range, 17-87 pg/mL) and 34 pg/mL (range, 4-93 pg/mL), respectively. The average decrease in PTH was 39% (range, 39%-90%). The incidence of hypocalcemia was significantly higher in patients with intraoperative PTH levels less than 15 pg/mL relative to patients with PTH levels greater than 15 pg/mL in this setting ( P=.006). In the 30 patients who underwent parathyroid exploration, average preoperative and postoperative PTH levels were 291 pg/mL (range, 65-1675 pg/mL) and 113.8 pg/mL (range, 6.5-1263 pg/mL) respectively. The intraoperative PTH level did not correlate with postoperative calcium levels in the parathyroid group. Percentages of decrease in PTH levels greater than 60% was statistically associated with surgical cure in this population. CONCLUSIONS: The study demonstrates that intraoperative PTH levels greater than 15 pg/mL after total or completion thyroidectomy indicate a low risk of postoperative hypocalcemia and that these patients may be candidates for outpatient surgery. In the parathyroid group, intraoperative PTH levels do not correlate well with postoperative calcium levels.

Calcium↗