Biomedical subjects

J D Day

Publications and source records attributed to J D Day.

At least 19 recordsLinked to original sources

PubMed2001

Exposure of mice to topical bovine thrombin induces systemic autoimmunity.

Bovine thrombin is used as an aid to hemostasis in medical and surgical procedures. At least 500,000 Americans are exposed to this therapeutic annually and reports suggest that exposure is associated with the development of autoreactive antibodies. To determine whether bovine thrombin can induce pathological autoimmunity we exposed nonautoimmune-prone galactose-alpha1-3-galactose-deficient mice to the two bovine thrombin preparations currently approved for use in the United States. We found that, like humans exposed to bovine thrombin, mice developed an immune response against the therapeutic and the xenogeneic carbohydrate galactose-alpha1-3-galactose, and some mice developed autoantibodies against clotting factors. Further, unexpectedly, a single exposure to this therapeutic also induced autoimmunity with features characteristic of systemic lupus erythematosus including antibodies against nuclear antigens, native DNA, double-stranded DNA, and cardiolipin. High levels of these autoantibodies correlated with glomerulonephritis in all mice evaluated. This autoimmune syndrome was detected in mice 15 weeks after a secondary exposure to bovine thrombin and female mice were found to develop the syndrome at a significantly greater frequency than males. Thus, these studies indicate that exposure to bovine thrombin preparations can induce a pathological systemic autoimmune syndrome with lupus-like serology.

Administration, Topical↗

PubMed2001

Early proactive management of vestibular schwannomas in neurofibromatosis type 2.

OBJECTIVE: The treatment of patients with neurofibromatosis Type 2 has always been challenging for neurosurgeons and neurotologists. Guidelines for appropriate management of this devastating disease are controversial. METHODS: A retrospective study of 28 patients with neurofibromatosis Type 2 who underwent 40 middle fossa craniotomies for excision of their acoustic tumors is reported. Eleven patients underwent bilateral procedures. The study focused on hearing preservation and facial nerve results for this group of patients. The 16 male patients and 12 female patients ranged in age (at the time of surgery) from 10 to 70 years, with a mean age of 22.6 years. The mean tumor size was 1.1 cm (range, 0.5-3.2 cm), and the majority of tumors were less than 1.5 cm. RESULTS: Measurable hearing was preserved in 28 ears (70%), with 42.5% being within 15 dB pure-tone average and 15% speech discrimination score of preoperative levels. In 55% of cases there was no change in the hearing class, as defined by the American Academy of Otolaryngology-Head and Neck Surgery. Of the 11 patients who underwent bilateral operations, 9 (82%) retained some hearing bilaterally. After 1-year follow-up periods (mean, 12.8 mo), 87.5% of patients exhibited normal facial nerve function (House-Brackmann Grade I). CONCLUSION: Early surgical intervention to treat acoustic tumors among patients with neurofibromatosis Type 2 is a feasible treatment strategy, with high rates of hearing and facial nerve function preservation.

Adolescent↗

PubMed2001

Microvascular decompression of the vestibulocochlear nerve for disabling positional vertigo: the House Ear Clinic experience.

OBJECTIVE: To review characteristics of and outcome in patients undergoing microvascular decompression of the vestibulocochlear nerve. Patients studied had a diagnosis of disabling positional vertigo caused by a vascular loop compressing the VIIIth cranial nerve. STUDY DESIGN: Retrospective chart review and telephone interview. SETTING: Private practice tertiary neurotologic referral center. PATIENTS: Twenty patients with disabling positional vertigo underwent 25 retrosigmoid craniotomies for microvascular decompression between November 1990 and June 1999. The 4 men and 16 women ranged in age from 30 to 71 years (mean age, 46 yr). MAIN OUTCOME MEASURES: Charts were reviewed and patients were contacted by telephone and asked to rate severity of symptoms (tinnitus and dizziness) on a 4-point scale (none = 1, mild = 2, moderate = 3, and severe = 4) before and after surgery. They were also asked to rate their overall disability from their symptoms on the six-point scale established by the American Academy of Otolaryngology-Head and Neck Surgery. Preoperative and postoperative four-frequency (500 Hz, 1 kHz, 2 kHz, and 4 kHz) pure-tone average and speech discrimination scores were calculated and compared. Complications of surgery are also reported. RESULTS: Postoperative tinnitus score and dizziness score showed significant improvement from preoperative scores (p < or = 0.047 and p < or = 0.001, respectively), with 80% of patients improved in dizziness rating; 85% improved in their overall disability rating, and the difference from preoperative to postoperative was significant (p < or = 0.001). The mean postoperative pure-tone averages (15.4 dB) and speech discrimination scores (99%) did not differ from preoperative scores (11.9 dB and 98%). One patient lost all vestibular function in the operated ear (hearing remained intact) as the only complication of surgery. When asked, 83% of patients responded that they would have the surgery again. CONCLUSIONS: Diagnosing disabling positional vertigo secondary to vascular compression of the VIIIth cranial nerve remains the clinical challenge; a clear history plus air-contrast computed tomographic or magnetic resonance imaging make the diagnosis. Microvascular decompression of the vestibulocochlear nerve is a safe and effective operation for these carefully selected patients.

Adult↗

PubMed2001

Intraoperative computerized tomography scanning to assess the adequacy of decompression in anterior cervical spine surgery.

OBJECT: The purpose of this study was to improve the accuracy of bone removal during anterior spinal surgery. Intraoperative computerized tomography (CT) scanning was used to assess the success of bone resection and permit immediate correction in the event of inadequate bone removal. METHODS: The Phillips Tomoscan M was used to obtain preoperative cervical scans before and after cervical bone resection was complete. The completeness of bone removal was assessed by the operating neurosurgeon by reviewing the postresection CT scan. If the bone removal was deemed inadequate, additional bone was removed using a high-speed drill. A CT scan was obtained after each subsequent decompression until adequate bone removal was achieved. In 31 patients undergoing anterior cervical decompression intraoperative CT scanning was performed. Nineteen patients underwent corpectomy and 12 discectomy. Of the 31 patients, assessment of intraoperative CT scans obtained in 17 indicated further bone removal was required. CONCLUSIONS: Intraoperative CT scanning to monitor bone removal during anterior cervical surgery is a valuable tool to ensure the adequacy of surgery.

Adult↗

PubMed2000

Cranial base surgical techniques for large sphenocavernous meningiomas: technical note.

OBJECTIVE: Large meningiomas arising from the dura covering the sphenoid ridge present surgical challenges because of frequent involvement of the carotid artery and its branches, the optic nerve and tract, the superior orbital fissure, and cavernous sinus structures. To circumvent the inherent difficulties of a traditional approach strategy, cranial base approaches were applied to: 1) isolate and interrupt the major blood supply as an initial step, 2) minimize brain retraction, and 3) isolate the neurovascular structures exiting the tumor at the cranial base to protect and better separate them. METHODS: Six patients were treated with such a strategy in the past 2 years (five women and one man, ages 34-69 yr). All tumors measured at least 5 cm in their greatest diameter and arose at the sphenoid ridge. All tumors extended posteriorly to involve the cavernous sinus to varying degrees. In two patients a frontotemporal bone flap was used; in two patients, a transzygomatic approach was used; and in the remaining two patients, an orbitozygomatic strategy was used. Extensive bone removal at the cranial base was performed in all cases. RESULTS: Four patients had gross total resections, and two were subtotal owing to invasion of the cavernous sinus or the middle cerebral artery. There were no permanent cranial nerve deficits; however, two patients sustained transient IIIrd nerve paresis. Two patients postoperatively developed transient cerebral edema that required intensive treatment. All six patients had good outcomes, resuming independent activity by 3 months after surgery. CONCLUSION: Contemporary cranial base surgical techniques have a role in the treatment of large sphenoid ridge meningiomas. These strategies result in safe resection with low morbidity and obviate the need in most cases for preoperative embolization. The anatomic foundation for using these approaches is discussed.

Adult↗

PubMed1999

Extended transbasal approach: anatomy, technique, and indications.

Appropriate indications for the transbasal approach have not been clearly established. The focus of this study is to determine the feasibility of maximal exposure of the clivus and surrounding regions via this strategy. Further, we sought to determine the key anatomical landmarks and morphometric data necessary for safe, radical exposure. In 20 injected cadaveric specimens, anatomical observations were made grossly and microscopically with 4-40 x magnification. The three basic variations of the transbasal craniotomy were compared with regard to surgical exposure. Maximum exposure of the ventral clivus could be obtained by total ethmoidectomy and sphenoidectomy through the extensive transbasal craniotomy. The lateral limits of exposure were found to be the optic nerves, intracavernous carotid arteries, and hypoglossal canals. Inferiorly, the foramen magnum is the limit of exposure. Morphometric measurements were determined between the key landmarks and were found helpful in subsequent dissections due to the lack of bony structures in relation to neural and vascular structures within the bone. The keys to optimizing the transbasal approach are beyond the simple initial steps of the craniotomy. Maximal exposure from the suprasellar compartment to the foramen magnum is possible via the extended transbasal approach.

Journal Article↗

PubMed1998

Context modulates effects of nicotine abstinence on human cooperative responding.

The effects of ad libitum smoking, abstinence, and 0-, 2-, and 4-mg nicotine gum on human cooperative responding were examined. Participants were provided the opportunity to respond cooperatively or independently to episodes initiated by a computer-simulated other person. Participants could also initiate episodes that ostensibly provided the other person the opportunity to respond cooperatively or independently of the participant. Working cooperatively added points to both the participant's and other person's counters. Working independently added points only to the participant's counter. Results demonstrated that abstinence decreased cooperative responses during episodes initiated by the computer-stimulated other person. Relative to abstinence and placebo gum conditions, ad libitum smoking and administration of 2- and 4-mg nicotine gum increased these cooperative responses. No gender differences were observed. The number of cooperative episodes initiated by the participants was not affected significantly by the smoking or gum conditions. Nicotine increased reports of vigor and decreased abstinence-engendered reports of depression, anger, confusion, and tension. The difference in the effects of nicotine abstinence on the 2 classes of cooperative responding demonstrates that the social contingency mediates the behavioral effects of abstinence.

Adolescent↗

PubMed1998

Anatomic position of the asterion.

OBJECTIVE: The asterion is defined as the junction of the lambdoid, parietomastoid, and occipitomastoid sutures. The asterion has been used as a landmark in lateral approaches to the posterior fossa. However, its reliability as a landmark comes into question considering the apparent variability of its position. This study was performed to determine the reliability of the asterion as a surgical landmark. METHODS: One hundred dried skulls were obtained for study. A 2-mm drill hole was placed at the asterion on each side. The position of the drill hole on the inner surface of the skull was next determined and recorded. RESULTS: The asterion was located over the posterior fossa dura in 32% on the right and 25% on the left. Its position was over the transverse or sigmoid sinus complex in 61% on the right and 66% on the left. The landmark was located above the transverse-sigmoid sinus complex in 7% on the right and 9% on the left. CONCLUSIONS: The asterion is not a strictly reliable landmark in terms of locating the underlying posterior fossa dura. Its location is very often directly over the transverse-sigmoid sinus complex. Burr holes placed at the asterion may often open the bone directly over the sinus, leading to potential damage.

Anatomy, Artistic↗

PubMed1998

The surgical management of trigeminal neuromas.

OBJECTIVE: Trigeminal neuromas are rare tumors that may involve any part of the nerve complex, including peripheral divisions of the nerve. These rare lesions are treated primarily surgically. We present our series of 38 patients who were treated surgically since 1981, with special emphasis on surgical approach. METHODS: We have surgically treated 38 patients with 39 trigeminal neuromas since 1981. This series of patients was reviewed with regard to clinical presentation, tumor characteristics, surgical approach, and outcome. RESULTS: Sixteen women and 22 men (mean age, 48 yr) all presented with some abnormality of trigeminal dysfunction. Twenty-eight patients presented with trigeminal hypesthesia, 10 with hypesthesia also had facial pain, 3 presented with only facial pain, and 7 presented with diplopia. Eighteen patients had tumors originating from the ganglion, nine from the posterior fossa nerve root, two from the ophthalmic division, and one from the mandibular division, and nine had tumors involving both posterior and middle fossae (dumbbell type). Eighteen tumors were large (>3 cm), 16 were medium sized (2-3 cm), and 5 were small (<2 cm). Tumor location was the prime determinant of surgical approach. Patients with peripheral and ganglion type lesions were treated via an entirely extradural temporopolar approach. Lesions confined to the posterior fossa were approached via a lateral suboccipital approach. Dumbbell-shaped lesions required a combined petrosal strategy. Total resection of tumor was accomplished in 30 patients. Three patients with subtotal resection displayed malignant histology. Postoperatively, 30 patients remained with some degree of trigeminal hypesthesia, two had facial pain (one persistent and one new), and five were left with total trigeminal anesthesia. Four patients were relieved of diplopia, five were relieved of headache, and two were relieved of ataxia. There were no perioperative deaths. CONCLUSION: Trigeminal neuroma is a surgically treatable disease that may be operated on, in many cases, via an entirely extradural approach. These lesions may be successfully resected with low morbidity and a very low rate of recurrence.

Adolescent↗

PubMed1998

The Quilty lesion enigma: focal apoptosis/necrosis and lymphocyte subsets in human cardiac allografts.

Quilty lesions, as first described by Billingham in 1981, or 'Quilty Effect' (QE) are distinct endomyocardial mononuclear cell infiltrates that have been observed in human heart transplant recipients, as well as in experimental models of heart transplantation. In the present investigations, the pattern and extent of apoptosis (programmed cell death) and myocyte necrosis, as well as specific lymphocyte subsets in Quilty lesions was assessed. Endomyocardial biopsies obtained from 13 patients at 10-3362 days post-transplant were examined. Apoptosis, as identified by DNA nick end-labeling, was found in myocytes at the periphery of Quilty lesions in 11 of 13 cases (85%), and 'early' stages of myocyte necrosis, as demonstrated by specific staining with alpha light chain myosin monoclonal antibodies (mAb), was observed at the same sites in 10 of 13 cases (77%) of both Quilty type A and type B lesions. Apoptosis was not identified in the lymphocyte infiltrates of any of the lesions examined. Lymphocyte subsets were characterized using mAb for T cell receptor (CD3), for helper/inducer T cells (CD4), for cytotoxic/suppressor T cells (CD8) and for mature B cells (CD20). Immunostaining revealed separate clusters of T lymphocytes with less prevalent B cells within the Quilty lesions. CD4+ cells were found in larger numbers than CD8+ cells in all cases. Non-B, non-T large lymphocytes were occasionally present. Except for the extent of the cellular infiltrate, no major cytochemical lymphocyte distribution differences were found between Quilty type A and B lesions. Myocyte apoptosis and early necrosis at the periphery of Quilty lesions suggest that early myocyte injury occurring in B lesions may represent initial or 'abortive stages' of cardiac allograft rejection. Why these lesions do not progress to overt rejection indeed warrant further detailed studies.

Actin Cytoskeleton↗

PubMed1998

Neurotopographic considerations in the microsurgical treatment of small acoustic neurinomas.

OBJECT: The authors studied the relationships between tumor size, location, and topographic position relative to the intact facial nerve bundles in acoustic neurinomas to determine the influence of these factors on hearing preservation postoperatively. Consistent topographic relationships were found. METHODS: Four hundred fifty-two patients with acoustic neurinoma treated via a retrosigmoid approach were analyzed with respect to hearing preservation and facial nerve function. One hundred fifteen tumors were identified as small and were categorized as Grades I and II. Patients with Grade I tumors, that is, purely intracanalicular lesions, all had good hearing preoperatively, defined by a less than 50-dB pure tone average and 50% speech discrimination score. All 14 Grade I tumors were removed, resulting in preservation of the patient's hearing by these criteria. There were no particular topographic anatomical relationships associated with these tumors that affected hearing preservation. Grade II tumors, defined as those protruding into the cerebellopontine angle without contacting the brainstem, were found in 101 patients and were divided by size into two grades: IIA (< 1 cm) and IIB (1-1.8 cm). In 90 patients with Grade IIA tumors, 72 (89%) of 81 who had preserved hearing preoperatively maintained it postoperatively, and in the 11 patients with Grade IIB tumors, six of whom had good hearing preoperatively, four (67%) had preserved hearing postoperatively. Six morphological types were identified based on their neurotopographic relationships to the elements of the vestibulocochlear nerve. CONCLUSIONS: Hearing preservation postsurgery by tumor type was as follows: 1A, 92%; 1B, 88%; 1C, 100%; 2A, 83%; 2B, 92%; and 3, 57%. Combined, this represents a hearing preservation rate of 87% after surgical treatment of Grade II acoustic neurinomas. Full nerve function was maintained in 88% of patients with anatomically preserved facial nerves in both Grade I and II tumors. The remaining 12% of patients retained partial function of the facial nerve. Two patients in the series lost anatomical integrity of the nerve due to surgery.

Audiometry, Pure-Tone↗

PubMed1997

Optimization of the operative corridor for the resection of craniopharyngiomas in children: the combined frontoorbitozygomatic temporopolar approach. Technical note.

Complete extirpation of tumor remains the primary goal of neurosurgeons in treating intracranial craniopharyngiomas. The intimate relationship of these lesions with the structures of the skull base and the difficulties of obtaining adequate operative visualization often make total removal an elusive goal. The authors describe the use of a combined fronto-orbitozygomatic temporopolar craniotomy to maximize the operative corridor and thereby increase the probability of maximum tumor resection without morbidity and mortality. They applied this approach in four children with craniopharyngiomas that involved the sellar and parasellar, third ventricle, cavernous sinus, and interpeduncular fossa regions. The surgical results are summarized with a presentation of pre- and postoperative imaging from two illustrative cases. A detailed description of the operative procedure is provided with a comparison to other previously described surgical approaches.

Journal Article↗

PubMed1997

The course of the prevertebral segment of the vertebral artery: anatomy and clinical significance.

BACKGROUND: The so called "pretransverse or prevertebral segment" of the vertebral artery is defined from its origin at the subclavian artery to its entry into the respective transverse foramen. In surgery, angiography, and in all noninvasive procedures it is of great importance to know the exact details of the course and the origin of this segment of the vessel as well as in which percentages real abnormalities can be found. METHODS: The VI segment of the vertebral artery was investigated both in anatomic preparations and clinical studies. A total of 402 vertebral arteries were evaluated (70 anatomic preparations in different forms, 181 patients, 95 angiographies of the aortic arch, and 86 color coded doppler sonographies). RESULTS: A contorted course was found in 157 (39%) cases. The plane of tortuosities demonstrated by the respective vessels was found to be horizontal in 40 (44.9%) cases, sagittal in 30 (33.7%) cases, and frontal in 19 (21.4%) cases. In 51 (32.5%) cases the contorted pathway was on the right side, and in 106 (68%) cases, on the left. A hypoplasia was found in 16 (10%) cases--11 (4.8%) right and 5 (2.2%) left. We further differentiated the convexity lying either medially or laterally in the transverse or frontal plane, or oriented dorsally or ventral in the sagittal plane. The exact location of the origin of the artery on the circumference of the subclavian artery (47% cranial, 44% dorsal, 3% ventral, 6% caudal) and also the average values of length and diameter are described. No significant differences between tortuous and nontortuous vessels were found with respect to length and diameter. A real abnormality of the origin of the vertebral artery was found in 8 (3.5%) cases. CONCLUSIONS: The described morphologic variations and frequencies of the VI segment of the vertebral artery have clinical applications in a wide field of pathologies in that region. To know about these findings seems to be very important not only in diagnosis (angiography, color coded doppler sonography) but also in their surgical and endovascular treatment.

Aorta, Thoracic↗

PubMed1997

Heads-up intraoperative endoscopic imaging: a prospective evaluation of techniques and limitations.

OBJECTIVE: Endoscopes have been used adjunctively for spinal and cranial microsurgical procedures and directly for ventricular exploration, fenestration, and catheterization. Technological advances now allow for multi-imaging technologies, including a so-called "heads-up display," allowing the surgeon to view the operative field and the endoscopic image simultaneously. INSTRUMENTATION: A high-resolution, active matrix liquid crystal display is built into the frame of the eyewear, with a display density of 182,000 pixels (280 x 650 pixels) and a resolution of 200 lines. The display occupies approximately 20% of the visual field. The headgear weighs 4 oz, with dimensions of 9 x 18 x 17 cm. The modular interface weighs 7 oz. Two different visualization systems can be used. The first uses a single integrated interface (IM 300), whereas the second (remote 900) is a 900-MHz frequency modulation wireless system that provides for a line-of-sight link between the NTSC source and the modular interface (range = 100 ft). RESULTS: Heads-up adjunctive endoscopy was used in 60 patients during 18 months. The procedures included 16 craniotomies, 1 intradural lumbar biopsy, and 42 ventriculoperitoneal shunt placements. Follow-up was obtained at a minimum of 1 year. Patient age ranged from 1 month to 58 years. The only complication was a transient loss of auditory evoked potentials after contact of the eighth nerve by the endoscope. CONCLUSION: We describe a portable, light-weight heads-up display imaging system, which we have used in 60 operative procedures. Benefits of the heads-up system include portability and a high-resolution digital monocular image, which reduces eye strain and vertigo. The ideal headgear will likely be an extremely high-resolution liquid crystal display-based or cathode ray tube-based semi-immersive system, with all of the benefits currently described for two-dimensional heads-up systems (i.e., light weight, portability, image quality, and the avoidance of complications associated with immersive systems).

Adolescent↗

PubMed1997

Direct microsurgery of dural arteriovenous malformation type carotid-cavernous sinus fistulas: indications, technique, and results.

OBJECTIVE: There is a subgroup of patients with Barrow Type D carotid-cavernous sinus fistulas (CCFs) who have progressive neurological deficits despite endovascular attempts at obliteration. To effectively arrest the progression of neurological deficits, especially visual loss, these patients require direct operative intervention. We have used a direct approach to such lesions, which comprehensively occludes all fistulous connections of the CCF. METHODS: We present a series of nine patients with Type D CCFs for which attempts at endovascular embolization failed and that, because of persistent symptoms, required surgical intervention. These lesions characteristically had extensive multiple external carotid artery feeders, often bilateral, in addition to the internal carotid artery feeders. The operative approach used was a combined extra- and intradural full exposure of the cavernous sinus and its contents, with identification and direct obliteration of all arterial input and selective ablation of the venous outflow from the cavernous sinus. RESULTS: All nine patients experienced resolution of their symptoms, and complete ablation of the lesions, as demonstrated by postoperative angiography, was achieved. Transient diplopia and trigeminal hypesthesia was observed in all nine patients, which resolved by 6 months postoperatively. One patient suffered from a temporary hemiparesis and another from permanent hemiparesis. There were no deaths related to surgery in this series. CONCLUSIONS: Patients with Type D CCFs who have persistent, progressive neurological deficits after failed endovascular attempts at obliteration may be treated by a direct surgical approach to ablate the fistulas. The pertinent anatomic concepts, indications for surgery, and operative techniques that are different from previously described methods are discussed.

Adolescent↗

PubMed1997

Cranial base approaches to posterior circulation aneurysms.

Aneurysms arising from the posterior circulation, especially when they are large and complex, continue to present a technical challenge. The development of cranial base strategies and principles has added to surgical management options. The authors used one of four cranial base approaches for the treatment of 30 patients with large and/or complex aneurysms arising from the vertebrobasilar circulation. These approaches included the extradural temporopolar, combined petrosal, retrolabyrinthine-transsigmoid, and the extreme-lateral inferior transtubercular exposure. The indications, technique, and results of each approach in this series are discussed, and a management paradigm is suggested for such aneurysms.

Adult↗

PubMed1996

Immunohistochemical evaluation of HER-2/neu expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasms.

Although several morphological and molecular genetic studies have implicated various grades of pancreatic duct hyperplasia as precursor lesions to infiltrating pancreatic adenocarcinoma, the identity of preinvasive pancreatic neoplasms remains controversial. In the present study, the authors examined the expression of the epidermal growth factor receptor homologue, HER-2/neu (c-erbB-2), in pancreatic duct lesions adjacent to infiltrating pancreas cancers in a series of 19 cases of pancreatic duct adenocarcinoma. HER-2/neu expression was examined because it has been identified in a proportion of infiltrating pancreas cancers and because it may provide early neoplasms with a growth advantage over adjacent nonneoplastic epithelium. In normal pancreatic ducts and ductules, HER-2/neu expression was absent in all but one case. By contrast, HER-2/neu was expressed in 82% (P = .008 vs normal ) of ducts with flat mucinous hyperplasia, 86% (P = .03 vs normal) of ducts with papillary mucinous hyperplasia without atypia, 92% (P = .001 vs normal) of ducts with atypical papillary mucinous hyperplasia, and all specimens with carcinoma in situ. HER-2/neu expression was observed in 69% (P = .002 vs normal) of the moderately differentiated infiltrating carcinomas and none of the poorly differentiated infiltrating carcinomas. These data establish HER-2/neu as a potential mediator of growth factor-related signal transduction in pancreatic duct lesions, and provide additional support for the hypothesis that lesions formerly regarded as various grades of hyperplasia instead may represent intraepithelial neoplasms with the potential for subsequent invasion and metastasis.

Adenocarcinoma↗

PubMed1996

Extradural total petrous apex resection with trigeminal translocation for improved exposure of the posterior cavernous sinus and petroclival region.

We have analyzed a strategy for improved exposure of the posterior cavernous sinus and petroclival region through an extradural subtemporal approach to be utilized in the removal of neoplastic processes with involvement of the apical petrous bone and posterior cavernous sinus. This surgical approach includes the following elements for improved exposure of the posterior cavernous sinus through the middle fossa corridor: (1) maximal extradural exposure and mobilization of the trigeminal nerve complex, allowing its elevation and anterior displacement, (2) complete extradural removal of the anterior petrous pyramid from the porus acousticus to the petrous apex under direct vision, (3) total exposure of the abducens nerve from the posterior fossa to its point of cross over the intracavernous carotid artery, and (4) wide extradural exposure of the cavernous carotid artery in the foramen lacerum region. This strategy can be combined with other related approaches; specifically, frontotemporal or posterior transpetrosal exposures for extensive lesions.Microsurgical dissection and morphometric analysis were performed in 20 fixed cadaver specimens for the purposes of validating the method for clinical application and determining the key elements to maximization of exposure. The trigeminal complex could be anteromedially retracted 4.8 mm +/- 1.3 (range = 3 to 6 mm) without skeletonization of V(2) and V(3). Liberating these two divisions from their bony canals to their first peripheral branch (10.4 mm +/- 2.5 and 5.4 mm +/- 1.1, respectively) resulted in increased mobilization an average of 9.1 mm +/- 1.7 (7 to 14 mm). Further mobilization is achieved by dividing the attachment between the trigeminal connective tissue sheath and the fibrous carotid ring at the foramen lacerum. An average of 13.0 mm +/- 3.1 (7 to 20 mm) of the posterior intracavernous carotid artery was exposed. Detailed microanatomic observations and a comprehensive morphometric analysis of the relevant anatomic relationships were made.

Journal Article↗