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Biomedical subjects

M P Fried

Publications and source records attributed to M P Fried.

At least 19 recordsLinked to original sources

Benchmarks for mortality, morbidity, and length of stay for head and neck surgical procedures.

OBJECTIVE: To determine benchmarks and factors that influence morbidity, mortality, and length of stay (LOS) for head and neck surgical procedures. METHODS: A specific database for head and neck surgical procedures was extracted from the National Hospital Data Survey database for 1995 through 1997. Records of inpatient admissions for patients undergoing head and neck surgery were examined to determine demographics, incidence of medical complications, mortality, and LOS. Data were statistically examined for the influence of medical complications on mortality and LOS. RESULTS: A total of 3932 patients underwent head and neck procedures. The overall medical morbidity and mortality rates were 5.65% and 2.98%, respectively. The presence of a major medical complication increased the odds of death by 5.65 (P<.001). Postoperative pneumonia was the most common medical complication (3.26%) and was associated with a mortality rate of 10.94% (odds ratio for mortality, 4.4). Acute myocardial infarction and stroke were rare (combined incidence, 1.86%) and were not statistically associated with increased mortality. Procedures that involved the esophagus carried the highest mortality rate (8.38%). The overall mean LOS was 6.15 days. This increased to 17.7 days when a major medical complication occurred (P<.001). Increasing age was associated with increased rates of medical complications and mortality (P<.001). CONCLUSIONS: Medical complications in patients undergoing head and neck surgical procedures are associated with increased mortality rates and longer LOS. Mortality rates in head and neck surgery are low but may be improved by preventing medical complications.

Age Factors↗

Assessment of the airway in obstructive sleep apnea syndrome with 3-dimensional airway computed tomography.

OBJECTIVE: The goal was to evaluate 3-dimensional airway CT for upper airway assessment in obstructive sleep apnea syndrome (OSAS). DESIGN: Airway CT was obtained and 3-dimensional airway models were constructed prospectively for 40 patients with OSAS and 10 controls. Airway dimensions were correlated with polysomnography, and comparison was made between patients with and without OSAS. RESULTS: OSAS patients had a mean respiratory distress index of 51.9 events per hour. The mean minimum cross-sectional area (XSA) in the neutral position was 67.1 mm(2). Minimum XSA decreased in both the inspiratory and expiratory phases to 16.3 mm(2) and 15.0 mm(2), respectively (P<0.001). Complete airway obstruction occurred in 1 or more phases of respiration in 28 patients. Neither airway XSA nor length of obstruction correlated with sleep apnea parameters. No statistically significant differences in airway dimensions were found between OSAS and control patients. CONCLUSIONS: Airway CT demonstrates dynamic airway obstruction in OSAS but does not correlate well with clinically important disease parameters.

Adult↗

Virtual laryngoscopy.

Virtual endoscopy enables computer-generated 3-dimensional visualization of a cavity by reconstructing 2-dimensional computed tomographic or magnetic resonance data. The technique has been used experimentally to study the colon, bronchi, ears, and other structures. Here, virtual laryngoscopies were created from the cross-sectional image data of 3 patients. The cases represented a normal airway, a squamous cell carcinoma of the glottic fold, and a posterior glottic stenosis. These reconstructions included extraluminal anatomy that is not typical of current virtual endoscopic techniques. The 2-dimensional computed tomographic and magnetic resonance images of the patients underwent post-processing for 3-dimensional reconstruction. The resulting models were imported into an experimental virtual endoscopy program for 1) airway lumen generation and 2) interactive viewing. Though they could not be used for biopsy, the virtual laryngoscopies provided, in a noninvasive fashion, good simulation of endoscopy. Virtual endoscopy also gave the added benefits of the ability to assess the transmural extent of disease and view the airway distal to areas of luminal compromise. This technology may well provide clinical benefit in preoperative planning, staging, and intraprocedural guidance for head and neck disease and merits further study.

Adult↗

Phase II trial of docetaxel, cisplatin, fluorouracil, and leucovorin as induction for squamous cell carcinoma of the head and neck.

PURPOSE: To evaluate the toxicity and efficacy of a 4-day regimen of docetaxel, cisplatin, fluorouracil, and leucovorin (TPFL4) in patients with locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Thirty previously untreated patients with stage III or IV SCCHN and Eastern Cooperative Oncology Group functional status of 2 or less were treated with TPFL4. Postchemotherapy support included prophylactic growth factors and antibiotics. Patients who achieved a complete response (CR) or partial response (PR) to three cycles of TPFL4 received definitive twice-daily radiation therapy. The primary end points were toxicity and response to TPFL4. RESULTS: Eighty-five cycles were administered to 30 patients. The major acute toxicities to TPFL4 were mucositis and nausea. One patient died of neutropenic sepsis during therapy. Additional major toxicities were neutropenia, anorexia, nephropathy, neuropathy, and diarrhea. Fourteen percent of all cycles were associated with hospitalization for toxicity. The overall clinical response rate to TPFL4 was 93%, with 63% CRs and 30% PRs. Primary tumor site clinical and pathologic response rates were 93% and 68%, respectively. CONCLUSION: TPFL4 has an acceptable toxicity profile in good-performance-status patients. Modification of the 5-day TPFL regimen (TPFL5: shorter chemotherapy infusion time, earlier intervention with growth factors and antibiotics) led to fewer episodes of febrile neutropenia and hospitalization. Response rates to TPFL justify further evaluation of combinations of these agents in the context of formal clinical trials.

Adult↗

Computer-augmented endoscopic sinus surgery.

Review of current literature on computer-augmented endoscopic sinus surgery reflects a sustained interest in developing a role for available frameless stereotactic technologies to provide image guidance for the surgeon. The interest is motivated by the prospect of increased intraoperative patient safety in that image guidance assists the surgeon in navigating through diseased or surgically revised complex anatomy. The authors feel that in time the technique will enable a new level of efficiency in endoscopic sinus surgery.

Endoscopy↗

Virtual otoscopy.

Imaging techniques assist the surgeon in diagnosis of disease, surgical planning, and providing image guidance during surgery. Endoscopy has the drawback of being a minimally invasive procedure and limiting visualization to the inner surface of the lumen. Ultrasound, CT, and MR imaging show volumes of tissue beyond the lumen wall; however, their planar, two-dimensional representations require mental reconstruction of anatomic structures, which often proves difficult with the small, complex structures within the temporal bone. To improve three-dimensional visualization of the inner ear, we successfully completed a virtual model that can be displayed as a contiguous, three-dimensional luminal view, known as virtual otoscopy, which emulates traditional endoscopy. A concomitant global view and a view of the related CT slice adds a distinct advantage in the presentation and study of this complex organ. Advances in computer and software technology may overcome the time and cost factors that, at present, limit widespread use of virtual otoscopy. Overall, virtual otoscopy stands as a promising new visualization technique for elucidation of the middle ear, inner ear, and temporal bone structures.

Computer Simulation↗

Endoscopic sinus surgery with magnetic resonance imaging guidance: initial patient experience.

We report the first endoscopic surgeries performed with patients under general anesthesia using intraoperative guidance with MRI. The procedures were experimental and intended to test (1) the unusual working environment of a unique new "open-configuration" MRI unit for head and neck surgery, and (2) real-time image guidance. Twelve patients underwent endoscopic sinus surgery while under general anesthesia in a new open MRI unit that provides the surgeon with access to the patient while imaging is performed. Eleven patients had chronic sinusitis (eight of them had bilateral disease), and one had a right nasoethmoid and antral tumor. All 12 surgeries were performed without complications. Both the endoscopic view and the MRI scans were available at the surgical field. The image plane was surgeon controlled, and the MRI updated images in as little as 14 seconds. MRI provided adequate visualization of both the disease and the related anatomy and allowed the surgeon to navigate during the procedure. The intraoperative data reflect the tissue changes during surgery and provide optimum feedback for surgical guidance. Although the operating environment poses some limitations, it has become apparent that intraoperative MRI has a role in the treatment of head and neck disorders and warrants further study.

Adult↗

Interactive magnetic resonance imaging-guided biopsy in the head and neck: initial patient experience.

Because of its excellent soft tissue resolution, magnetic resonance imaging (MRI) can optimize image guidance for interventional and surgical procedures. Notably, needle biopsy of head and neck lesions has been used for years, deeper lesions often requiring some form of image guidance. The closed space of diagnostic MRI scanners proves cumbersome for intervention. The authors report on the first head and neck image-guided biopsies performed in a new, investigational "open configuration" intraoperative MRI scanner. Vertical space between the scanner's upright coils gives access to the patient while imaging; image acquisition is as fast as 2 sec/image. Biopsies were performed on seven patients (parotid, parapharyngeal space, second cervical vertebra); five specimens were diagnostic. Both general anesthesia and intravenous sedation were used. The procedures were without complications. Imaging provided definition of anatomy to direct needle placement. Access to the patient allowed for both percutaneous and transoral approaches. The environment of the open magnet is well suited for biopsy of the head and neck, and near real-time intraoperative MRI has promise for guiding more complex head and neck procedures. Further study should optimize the quality of the images and the interactibility of localization and targeting and fully utilize MRI's three-dimensional imaging capabilities.

Adenoma, Pleomorphic↗

Computer-assisted three-dimensional reconstruction of head and neck tumors.

OBJECTIVE: Because head and neck tumors reside in a complex area, having a three-dimensional (3-D) model of the patient's unique anatomical features may assist in the delineation of pathology. The authors describe a new computer technique of 3-D anatomical reconstruction from two-dimensional computed tomography (CT) and magnetic resonance (MR) data and discuss how it represents a step forward in the continuing evolution of 3-D imaging. STUDY DESIGN: The authors selected three patients with solitary head and neck tumors and reconstructed their anatomy in a 3-D format for study. The tumors represented locations in the nose and central skull base (patient 1), temporal bone (patient 2), and neck (patient 3). MATERIALS AND METHODS: MR and CT images from the individual patients were electronically transferred to workstations in the Surgical Planning Laboratory of the authors' institution. Registration (or fusion) was carried out between the MR and CT images. The desired anatomic components underwent segmentation (identification and isolation). Assembly of the segmented images was performed and the resulting structures were integrated to produce a 3-D model. RESULTS: 3-D models of the following were constructed and displayed in an interactive format on high-capacity computer workstations: 1) a skull base sarcoma with extension into the nasopharynx and nose; 2) an acoustic neuroma with internal auditory canal involvement; and 3) a metastatic recurrence of a tongue base squamous cell carcinoma in the posterior triangle of the right side of the neck with extension to the skull base. CONCLUSION: The authors' Surgical Planning Laboratory has developed a 3-D reconstruction technique that has several new features. The models provided a very good 3-D interactive representation of the tumors and patient anatomy. The need now exists to develop this method of 3-D reconstruction of head and neck tumors for potential applications in treatment, research, and medical education.

Adult↗

MR-guided endoscopic sinus surgery.

We describe an interactive, intraoperative imaging-guided method for performing endoscopic sinus surgery (ESS) within a vertically open MR system. The procedure was performed with intraoperative imaging using a 0.5-T magnet with a 56-cm vertical gap. Interactive control of imaging planes was accomplished by optical tracking with two infrared light-emitting diodes mounted on an aspirator probe. The probe's position defined the location of the orthogonal imaging planes. Twelve patients with varying degrees of sinus disease underwent ESS with MR imaging guidance. Patients had acute and chronic sinusitis, nasal polyposis causing airway obstruction, or tumor requiring tissue biopsy. All procedures were performed with the patients under general anesthesia. The integration of endoscopy with optical tracking and intraoperative interactive imaging allowed localization of anatomic landmarks during ESS. No complications were encountered.

Acute Disease↗

Efficacy of laser-assisted uvulopalatoplasty.

BACKGROUND AND OBJECTIVE: Laser-assisted uvulopalatoplasty (LAUP) is being used increasingly as a surgical treatment for snoring and obstructive sleep apnea (OSA). There is limited evidence for the success of LAUP in eliminating OSA. This study assesses the efficacy of LAUP in eliminating snoring and OSA and addresses which patients may be the best candidates for LAUP treatment. STUDY DESIGN/MATERIALS AND METHODS: From January 1994 to January 1996, 297 patients were evaluated for snoring, with 190 (64%) exhibiting some degree of OSA documented by a PSG: 41/ 190 (22%) mild OSA; 33/190 (17%) moderate OSA; 85/190 (45%) severe OSA; 31/190 (16%) severity unknown. Ninety patients (90/ 297) have undergone LAUP treatment: 58/90 (64%) with OSA and 32/90 (36%) with snoring only. RESULTS: Our results indicate a significant reduction of snoring in patients without OSA, but diminishing success in patients with increasing degrees of OSA. Additionally, LAUP was not efficacious in treating OSA: pre-op respiratory disturbance index (RDI) of 10.8 vs. post-op RDI of 19.5 for mild OSA (P = 0.14); pre-op RDI of 22.9 vs. post-op RDI of 25.4 for moderate OSA (P = 0.43); pre-op RDI of 56.8 vs. post-op RDI of 46.3 (P < 0.05), which is statistically but not clinically significant (i.e., RDI remained in the severe range). CONCLUSION: We conclude that LAUP is an effective treatment for nonapneic snoring, but does not provide sufficient resolution of OSA, and based on our results, LAUP should be considered as an adjunctive therapy rather than a sole treatment for OSA in most cases.

Adult↗

Image-guided endoscopic surgery: results of accuracy and performance in a multicenter clinical study using an electromagnetic tracking system.

Image-guided surgery has recently been described in the literature as a useful technology for improved functional endoscopic sinus surgery localization. Image-guided surgery yields accurate knowledge of the surgical field boundaries, allowing safer and more thorough sinus surgery. We have previously reviewed our initial experience with The InstaTrak System. This article presents a multicenter clinical study (n=55) that assesses the system's capability for localizing structures in critical surgical sites. The purpose of this paper is to present quantitative data on accuracy and performance. We describe several new advances including an automated registration technique that eliminates the redundant computed tomography scan, compensation for head movement, and the ability to use interchangeable instruments.

Adolescent↗

Anatomic location of the tongue base neurovascular bundle.

Knowledge of the location of the hypoglossal/lingual artery neurovascular bundle (HLNVB) is essential in performing tongue base resections for neoplasm and for obstructive sleep apnea. Transoral and transcervical resections of the tongue base may be performed with greater exposure and certainty when the relationship of the HLNVB to local landmarks is understood; knowledge of the HLNVB allows resection of a larger amount of contralateral tongue base during partial glossectomy without violating the contralateral remnant tongue's blood supply. Ten cadaver heads were dissected to determine the position of the HLNVB with respect to soft tissue and bony landmarks at the tongue base. Our results indicate the position of the tongue base HLNVB is significantly inferior and lateral, that is, 2.7 cm inferior and 1.6 cm lateral to the foramen cecum, 0.9 cm superior to the hyoid bone, and 2.2 cm medial to the mandible. This inferolateral location allows the potential for aggressive tongue base resection without neurovascular compromise.

Humans↗

Dynamic T1-weighted magnetic resonance imaging of interstitial laser photocoagulation in the liver: observations on in vivo temperature sensitivity.

BACKGROUND AND OBJECTIVE: Magnetic resonance imaging's (MRI) potential to monitor interstitial laser photocoagulation (ILP) has been previously demonstrated and is further tested here with improved spatial and temporal resolution. STUDY DESIGN/MATERIALS AND METHODS: In vivo experiments employed fiber-delivered 1,064 nm light (3.0 W, 150 sec) in six rabbit livers monitored under T1-weighted FSE MRI as 1 image/10 sec and a 3 mm thick 8 cm FOV. Image signal intensities (SI) were compared with temperatures (T) at 7, 10, and 15 mm from the fiber. RESULTS: Data showed 33 degrees C < T < 60 degrees C. SI did not vary inverselinearly with T; changes in the tissue altered the MRI signal interfering with the SI changes due to temperature. CONCLUSION: MRI cannot map SI-derived temperatures over the entire treatment site. The role of MRI's temperature sensitivity must be coordinated with organ- and dose-specific tissue changes.

Animals↗

Image-guided surgery in a new magnetic resonance suite: preclinical considerations.

Surgical procedures require correct identification of exposed anatomy with concomitant localization amidst contiguous structures. In endoscopic procedures the surgeon is provided a real-time endoscopic view and is prepared with radiologic images. Here we present an overview of a methodology of localization using intraoperatively acquired magnetic resonance (MR) images in preparation for magnetic resonance imaging-guided endoscopic sinus surgery. The methodology centers around a unique prototype imaging device and operating environment. An "open" 0.5 Tesla MR unit has been created that allows complete access to the patient's head and neck while concomitant images are obtained. Illustrative examples of localization technique from cadaver experiments are presented, as well as insights into the host of concerns for anesthesia, equipment, surgical instrumentation, communications, and documentation.

Anesthesia↗

Image guidance with laser applications.

Image-guided laser surgery is defined, and an outline of its development is provided. Recent advances in radiologic imaging provide added visualization of laser-induced tissue effects. Current research around the world illustrates the power and potential of this technique in both laser and nonlaser applications. Future studies will reveal the actual contribution to laser surgery in otolaryngology.

Animals↗