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Biomedical subjects

L J Marentette

Publications and source records attributed to L J Marentette.

At least 19 recordsLinked to original sources
PubMed2001

Radiation concurrent with gemcitabine for locally advanced head and neck cancer: a phase I trial and intracellular drug incorporation study.

PURPOSE: To examine the feasibility and dose-limiting toxicity (DLT) of once-weekly gemcitabine at doses predicted in preclinical studies to produce radiosensitization, concurrent with a standard course of radiation for locally advanced head and neck cancer. Tumor incorporation of gemcitabine triphosphate (dFdCTP) was measured to assess whether adequate concentrations were achieved at each dose level. PATIENTS AND METHODS: Twenty-nine patients with unresectable head and neck cancer received a course of radiation (70 Gy over 7 weeks, 5 days weekly) concurrent with weekly infusions of low-dose gemcitabine. Tumor biopsies were performed after the first gemcitabine infusion (before radiation started), and the intracellular concentrations of dFdCTP were measured. RESULTS: Severe acute and late mucosal and pharyngeal-related DLT required de-escalation of gemcitabine dose in successive patient cohorts receiving dose levels of 300 mg/m(2)/wk, 150 mg/m(2)/wk, and 50 mg/m(2)/wk. No DLT was observed at 10 mg/m(2)/wk. The rate of endoscopy- and biopsy-assessed complete tumor response was 66% to 87% in the various cohorts. Tumor dFdCTP levels were similar in patients receiving 50 to 300 mg/m(2) (on average, 1.55 pmol/mg, SD 1.15) but were barely or not detectable at 10 mg/m(2). CONCLUSION: A high rate of acute and late mucosa-related DLT and a high rate of complete tumor response were observed in this regimen at the dose levels of 50 to 300 mg/m(2), which also resulted in similar, subcytotoxic intracellular dFdCTP concentrations. These results demonstrate significant tumor and normal tissue radiosensitization by low-dose gemcitabine. Different regimens of combined radiation and gemcitabine should be evaluated, based on newer preclinical data promising an improved therapeutic ratio.

Adult↗
PubMed2001

Correction of nonsyndromal craniosynostosis.

Correction of craniosynostosis requires close collaboration between the craniofacial surgeon and the neurosurgeon. Typically, nonsyndromal craniosynostosis patients will require only one operation to correct the cranial vault deformity. The procedures usually are undertaken between 3 and 6 months of age. Any gaps are filled in with new bone because the dura is highly osteogenic. The early correction of these deformities can avoid future facial deformities as a result of restricted skull base growth causing maxillary and secondary mandibular deformities.

Craniosynostoses↗
PubMed1999

Critical pathways in anterior cranial base surgery.

New advances in anterior cranial base surgery have dictated the need for a comprehensive, multidisciplinary approach in the treatment of lesions of this area, necessitating multiple modes of diagnostic and surgical techniques. Traditional consideration of the complex problems presented by neoplastic involvement of the anterior cranial base predicated on isolated syndrome analysis is no longer sufficient to adequately assess tumor pathology. To address these complex problems, we discuss a method of localization of pathology based on anatomic structure and function as well as the corresponding surgical approach to the anterior cranial base.

Cavernous Sinus↗
PubMed1999

Subcranial approach to tumors of the anterior cranial base: analysis of current and traditional surgical techniques.

Tumors of the anterior cranial base have previously required a craniofacial resection to allow adequate tumor extirpation. An analysis of current and traditional techniques demonstrates a significant reduction in operative time, complication rate, and intensive care unit and total hospital length of stay with the use of the subcranial approach as compared with the traditional frontal craniotomy and lateral rhinotomy approach. The subcranial approach is both cost and time efficient and provides comparable morbidity and mortality rates.

Blood Loss, Surgical↗
PubMed1999

Craniofacial resection: decreased complication rate with a modified subcranial approach.

The authors have successfully utilized a modified subcranial approach to the anterior skull base, based upon the procedure first described by Joram Raveh, as an alternative to standard craniofacial resection. The complication rate of this procedure in 31 consecutive cases (28 tumors, 2 congenital malformations, and 1 mucocele) has been 19.4% with no permanent complications, no deaths, no new neurological deficits, no brain injuries, no infections, and no seizures. Minor complications without permanent sequelae included two cases of tension pnenmocephalus, a subdural hygroma, two transient cerebrospinal fluid leaks, and a case of bacterial meningitis secondary to fecal contamination of a lumbar drain in a child. Average length of hospitalization was 7.1 days (range 2 to 16 days). The overall complication rate is considerably below the complication rate for other reported craniofacial procedures. We describe the technique we have used and the results. The subcranial approach as described herein provides wide exposure of the anterior cranial base without brain retraction, does not require prolonged operating times or hospitalization, and has a potentially lower complication rate than reported for other transfrontal transbasal approaches.

Journal Article↗
PubMed1999

Use of hydroxyapatite bone cement to prevent cerebrospinal fluid leakage through the frontal sinus: technical report.

OBJECTIVE: To test the efficacy of a simple technique of frontal sinus obliteration during low frontal craniotomy using hydroxyapatite cement instead of more traditional methods, such as pericranial flaps, free muscle or adipose grafts, lumbar drainage, or fibrin glue. METHODS: Eight patients undergoing low frontal craniotomy for intradural surgery had the frontal sinus obliterated by careful removal of mucosa followed by filling of the sinus with hydroxyapatite bone cement. No other adjuncts for preventing cerebrospinal fluid leakage through the sinus were used. RESULTS: At an average follow-up of 9 months, there were no cerebrospinal fluid leaks, infections, instances of resorption, or cosmetic deformities. CONCLUSION: Hydroxyapatite bone cement seems to be a simple and effective method for frontal sinus obliteration and prevention of cerebrospinal fluid leakage.

Aged↗
PubMed1997

Outcome analysis of the transglabellar/subcranial approach for lesions of the anterior cranial fossa: a comparison with the classic craniotomy approach.

The classic approach to anterior skull base lesions uses bifrontal craniotomies together with lateral rhinotomies. This approach requires frontal lobe retraction and is associated with postoperative anosmia and the development of frontal lobe encephalomalacia. The transglabellar/subcranial approach permits removal of anterior skull base lesions without frontal lobe retraction and avoids facial scars. No studies to date, however, have directly compared the two approaches in terms of patient morbidity. The present retrospective study compares the two approaches when used for the removal of anterior skull base lesions in terms of estimated blood loss, number of transfusions, number of days in the hospital and intensive care unit, and postoperative complications. Twenty patients with anterior skull base lesions were examined. The classic approach was used on 10, and the transglabellar/subcranial route was used on 10. When compared with the classic approach, the transglabellar/subcranial approach resulted in a lower estimated blood loss and subsequent transfusion rate, fewer days in the hospital and intensive care unit, and lower numbers and less severe types of complications. Furthermore, visualization of the tumors before resection with the transglabellar/subcranial approach allowed preservation of olfaction in virtually all of these patients. Although this study represents a small sample population, the results are sufficiently impressive to favor the transglabellar/subcranial approach for the removal of a variety of anterior skull base lesions.

Adult↗
PubMed1996

Osteoradionecrosis of the anterior cranium.

Osteoradionecrosis occurs in approximately 10% to 15% of patients following radiation therapy for head and neck cancer. In these patients, it is most commonly reported in sites involving the mandible, but it has also been reported in the maxilla, sphenoid, and temporal bones. The majority of these cases are related to some type of trauma such as dental extraction or intraoral biopsies. However, approximately 40% of these entities occur spontaneously and are felt to be secondary to cell kill in intermediate tissues such as bone and periosteum. Our literature review yielded no previously reported cases of osteoradionecrosis involving the anterior cranium. The following two cases present patients who experienced osteoradionecrosis of their frontal bone flaps following subcranial approaches for tumor resection. Both patients suffered from carcinomas involving the ethmoid sinuses; one tumor was a moderately well-differentiated squamous cell carcinoma, the other a mucinous adenocarcinoma. One patient's radiation therapy consisted of external beam photons; the other patient received external beam neutrons. Treatment for these patients, as well as possible causative factors regarding their osteoradionecrosis, are discussed.

Case Reports↗
PubMed1995

Supplemental maxillomandibular fixation with miniplate osteosynthesis.

Monocortical miniplate fixation provides biomechanical fixation of mandibular fractures. The ability of this system to adequately fixate fractures clinically has not been fully accepted. We analyzed our use of supplemental maxillomandibular fixation with miniplate osteosynthesis during a 5-year period, in 287 patients with 499 mandible fractures. A retrospective, matched pairing of identical fractures fixated with identical plating-schemes was carried out. Sixty-five pairs of patients undergoing intraoral monocortical plating were identified. Patients in group 1 were treated with supplemental maxillomandibular fixation after surgery, whereas patients in group 2 were treated without postoperative maxillomandibular fixation. The rate of major complications was 11% with supplemental maxillomandibular fixation and 9% without supplemental maxillomandibular fixation (p > 0.05). The total rate of complications was 17% with supplemental maxillomandibular fixation and 20% without supplemental maxillomandibular fixation (p > 0.05). No statistically significant outcome advantage could be attributed to the use of maxillomandibular fixation.

Bone Plates↗
PubMed1994

Intraoral monocortical miniplating of mandible fractures.

OBJECTIVE: Intraoral monocortical miniplate fixation of mandibular fractures provides simultaneous visualization of the fracture and occlusal relation, while almost eliminating external incisions and potential compromise of the marginal mandibular nerve. We sought to analyze the outcome of our patients treated with this technique and compare this with literature standards for mandible fracture repair outcome. DESIGN: A retrospective analysis of outcomes for a case series. SETTING: All treatment performed in inner city, level 1 or 2 trauma rated, teaching hospitals. PATIENTS: During a 5-year period, 287 patients with 499 mandible fractures were treated with intraoral miniplates. Follow-up criteria was available for a retrospective analysis of 246 patients with 432 fractures of the mandible. INTERVENTION: Intraoral monocortical plating techniques were used to treat 313 of these 432 mandibular fractures. MAIN OUTCOME MEASURES: All complications of bone union, occlusion, wound infection, and dehiscence were graded and tabulated. RESULTS: On analysis of the miniplated fractures, 1.2% of the patients had delayed union, 0.4% had non-union, 6.5% had postoperative wound infection develop, and 4.1% had varying degrees of malunion. Complication rates are comparable with most reported studies of bicortical and monocortical plating of mandible fractures. CONCLUSIONS: Monocortical miniplate fixation is a reliable method of providing rigid fixation. It offers a reasonable alternative to bicortical plating in most mandible fractures.

Bone Plates↗
PubMed1993

Calvarial bone graft harvest. Techniques, considerations, and morbidity.

The importance of calvarial bone grafting in craniomaxillofacial trauma and facial reconstructive surgery is now widely recognized. Numerous harvesting techniques have evolved to optimize the desired thickness, size, shape, and curvature for a particular reconstructive need. At the same time, donor site selection and morbidity must be considered. This report includes a discussion of several currently utilized calvarial bone graft harvesting techniques, with emphasis on minimizing complications and morbidity. Choice of optimal harvesting technique and donor site for specific reconstructive situations will likewise be discussed. Finally, the specific morbidity in our multi-institutional calvarial bone graft harvest series of 121 patients and over 350 grafts will be reviewed.

Bone Transplantation↗
PubMed1993

The coronal approach. Anatomic and technical considerations and morbidity.

The coronal flap has recently become a preferred approach for the otolaryngologist-head and neck surgeon requiring access to the craniofacial skeleton and orbit. The variety of cases in which it has proven indispensable include craniofacial reconstruction, facial trauma, and tumor resection. This method of exposure has become particularly useful with increased indications for rigid internal fixation and primary bone grafting in the management of complex facial fractures. Our experience is reviewed in terms of indications for and benefits of the coronal approach, with a detailed description of the technique emphasizing anatomic planes and neurovascular structures. Careful attention to the latter should allow prevention of potential complications.

Facial Nerve↗
PubMed1993

Lag screw fixation in the upper craniomaxillofacial skeleton.

Rigid internal fixation of the craniomaxillofacial skeleton has become commonplace in osseous reconstructive procedures of the face. While miniplates are useful in many traumatic, reconstructive, and congenital anomaly cases, they are often unnecessary. Lag screw fixation is routinely used in the mandible and has the advantage of maximal stability when compared with other fixation techniques. These principles can similarly be applied in a variety of situations in the upper facial skeleton, including fracture and bone graft fixation, as well as in pediatric craniofacial surgery. We review the technique and appropriate indications and demonstrate via case examples this diversity of applicability for using lag screw techniques. Finally, results of 83 cases in which this technique has been used will be reviewed, including complications.

Bone Screws↗
PubMed1993

Injuries of the hard palate and the horizontal buttress of the midface.

Traumatic injuries to the hard palate occurred in 20% of all Le Fort midfacial fractures. The side of a palatal split was directly related to the side that received the highest Le Fort injury. In a symmetric midfacial injury, the palate had a true midline split. Repair of palatal injuries from blunt trauma involved either wire and splinting (eight patients) or miniplate fixation without a splint (11 patients). There were fewer complications in those treated by the miniplate fixation technique (two of 11), as compared to those treated with wire and splinting (four of eight). In miniplate fixation of midfacial fractures, attention is focused on the reconstruction of the supporting buttresses of the midface, both vertical and horizontal. In regard to the palate, this requires union of the inferior horizontal buttress. Gunshot wounds accounted for 21% of the patients and resulted in large bony disruption of the palate, which required free soft tissue and bone grafts for repair of the inferior horizontal buttress.

Adolescent↗
PubMed1993

A practical methodology to analyze facial deformities.

Despite much information about various methods to analyze the face, a practical stepwise methodology has not been firmly established in otolaryngology teaching programs. A general guideline for facial analysis would be helpful to individuals not totally familiar with facial analysis for assessing facial deformities resulting from to traumatic, neoplastic, or developmental causes. This article attempts to distill and integrate previously established guidelines for facial analysis into eight major steps to provide a preliminary and practical methodology for initial facial assessment.

Algorithms↗
PubMed1993

Rehabilitation of the lower cranial nerves.

Brain stem lesions frequently cause dysfunction of the lower cranial nerves. Even with successful treatment, dysfunction may remain. Various methods for rehabilitating the patient with persistent lower cranial nerve dysfunction are presented.

Accessory Nerve↗