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Biomedical subjects

F Porchet

Publications and source records attributed to F Porchet.

30 records · Page 2Linked to original sources
PubMed1998

Cervical amyloidoma of C2. Case report and review of the literature.

STUDY DESIGN: Second published report of a patient with amyloidoma of the upper cervical spine. OBJECTIVES: To describe a patient with rare radiculopathy to alert other physicians to consider amyloid tumor as a differential diagnosis of locally destructive spine lesions. SUMMARY OF BACKGROUND DATA: Localized amyloid tumor of the bone is a rare disease. Only seven cases of spine involvement have been reported. Appropriate tissue sampling is required to establish the diagnosis. Histopathologic examination shows pathognomonic apple-green birefringence under polarized light. When bone is involved with amyloid, it is most commonly associated with multiple myeloma or other plasma cell-dyscrasias. METHOD: This case was described, and pertinent literature was reviewed. RESULTS: The patient showed persistent neurologic improvement after transoral complete tumor removal, followed by a secondary posterior stabilization procedure using transarticular C1-C2 screws. CONCLUSIONS: Amyloidomas are benign lesions with no associated documented risk for the development of plasmocytoma-related diseases. The clinical and radiographic manifestations of this lesion are nonspecific. A cure is possible with complete resection of the tumor and no adjuvant management procedures.

Aged↗
PubMed1998

[The effect of position on intracranial pressure].

The question as to whether the head and trunk of neurosurgery patients should be elevated remains controversial. This question is particularly important when intracranial hypertension is present. Head up position may have beneficial effects on intracranial pressure (ICP) via changes in mean arterial pressure (MAP), airway pressure, central venous pressure and cerebro spinal fluid displacement. However, in some circumstances, head up position may decrease MAP which in turn will result in a paradoxical rise in ICP through autoregulation mechanisms. Therefore, the degree of head elevation has to be titrated by evaluating the most adequate cerebral perfusion pressure (CPP) for each patient by means of transcranial Doppler or measurement of jugular venous blood oxygen saturation. Head elevation above 30 degrees should be avoided in all cases. In most patients with intracranial hypertension, head and trunk elevation up to 30 degrees is useful in helping to decrease ICP, providing that a safe CPP of at least 70 mmHg or even 80 mmHg is maintained. Patients in poor haemodynamic conditions are best nursed flat. CPP is thus the most important factor in assessment and monitoring when considering head elevation in patients with increased ICP.

Humans↗
PubMed1998

Clinical assessment of a novel antiadhesion barrier gel: prospective, randomized, multicenter, clinical trial of ADCON-L to inhibit postoperative peridural fibrosis and related symptoms after lumbar discectomy.

A prospective, multicenter, randomized, double-blind, controlled study of ADCON-L Anti-Adhesion Barrier Gel (a medical device by Gliatech Inc, Cleveland, OH) was conducted in 298 patients undergoing first-time lumbar discectomy to evaluate the safety and effectiveness of ADCON-L in preventing postoperative peridural fibrosis and in improving patient clinical outcome. After lumbar discectomy, patients were randomized to receive either ADCON-L gel or nothing (control group) at the conclusion of the surgical procedure. Six months after surgery, peridural scar was evaluated by magnetic resonance imaging, and postoperative pain and straight-leg-raise angle were assessed. No statistically significant differences between the ADCON-L and control groups were observed in terms of adverse events or wound healing characteristics. ADCON-L gel was shown to be safe and to significantly inhibit peridural scar compared with the control group (P = 0.002). That peridural scarring was reduced with ADCON-L gel was further supported by direct visualization of scar tissue at reoperation in both groups. ADCON-L-treated patients had better clinical outcomes than did control patients. The incidence of activity-related pain was significantly reduced (P = 0.013), straight-leg-raise examination scores were significantly improved (P = 0.024 on the operative side and P = 0.015 on the nonoperative side), and ADCON-L reduced low back pain when it was most severe (P = 0.047) and at the end of the day (P = 0.044).

Adult↗
PubMed1996

Gene therapy for amyotrophic lateral sclerosis (ALS) using a polymer encapsulated xenogenic cell line engineered to secrete hCNTF.

The gene therapy approach presented in this protocol employs a polymer encapsulated, xenogenic, transfected cell line to release human ciliary neurotrophic factor (hCNTF) for the treatment of Amyotrophic Lateral Sclerosis (ALS). A tethered device, containing around 10(6) genetically modified cells surrounded by a semipermeable membrane, is implanted intrathecally; it provides for slow continuous release of hCNTF at a rate of 0.25 to 1.0 micrograms/24 hours. The semipermeable membrane prevents immunologic rejection of the cells and interposes a physical, virally impermeable barrier between cells and host. Moreover, the device and the cells it contains may be retrieved in the event of side effects. A vector containing the human CNTF gene was transfected into a line of baby hamster kidney cells (BHK) with calcium phosphate using a dihydrofolate reductase-based selection vector with a SV40 promoter and contains a HSV-tk killer gene. hCNTF is a potent neurotrophic factor which may have utility for the treatment of ALS. Systemic delivery of hCNTF in humans has been frustrated by peripheral side effects, the molecule's short half life, and its inability to cross the blood-brain barrier. The gene therapy approach described in this protocol is expected to mitigate such difficulties by local intrathecal delivery of a known quantity of continuously-synthesized hCNTF from a retrievable implant.

Amyotrophic Lateral Sclerosis↗
PubMed1996

Unusual complications at iliac crest bone graft donor site: experience with two cases.

OBJECTIVE AND IMPORTANCE: Two cases of fracture of the iliac crest after graft harvesting are presented. Only six such cases have been reported in the literature, although more than 100,000 such procedures are performed each year in the United States alone. This complication adds to the morbidity of the procedure for which the graft is taken. Its avoidance by an appropriate harvesting technique will reduce patient disability and shorten hospital stay. CLINICAL PRESENTATION: A 56-year-old man who worked as a mechanic underwent anterior cervical discectomies and fusion at C5-C6 and C6-C7 for spondylotic radiculopathies. Another patient, a 48-year-old man, required mandibular reconstruction for squamous cell carcinoma. Both grafts were harvested from the iliac crest using osteotomies. On the 9th and 3rd postoperative days, respectively, each patient developed groin pain while walking, associated with marked tenderness over the graft donor sites. X-rays showed fractured iliac crests. INTERVENTION: Apart from bed rest for pain, no specific treatment was required. CONCLUSION: The use of the osteotome weakens the iliac crest, leading to stress fractures caused by the pulling action of the attached muscles. To prevent this from happening, we recommend the use of the oscillating saw, leaving a 3-cm spike of iliac crest anteriorly. Nevertheless, this complication has a good long-term outcome.

Bone Transplantation↗
PubMed1995

Hypotensive effect of nimodipine during treatment for aneurysmal subarachnoid haemorrhage.

To determine the incidence of induced systemic hypotension in patients after aneurysmal subarachnoid haemorrhage (SAH) and nimodipine treatment 87 consecutive cases were reviewed. The patients were managed according to the same Nimodipine treatment protocol. After confirmation of SAH the nimodipine treatment was started as a continuous intravenous perfusion at a dosage of 0.5 mg/h and gradually increased every 6 hours if haemodynamically tolerated until the maintenance dose of 2 mg/h was reached. Median systemic pressure was continuously measured and tolerated until a lowest limit of 75 mmHg. In 31 patients (36%) hypotension with values below 75 mmHg during at least 30 minutes was noted and needed Nimodipine reduction. Intravenous Nimodipine administration was responsible for hypotension in 26 cases as compared to 5 cases due to oral administration. 38% of all patients required support by vaso-active agents (Dopamine or Nor-adrenaline). There was no statistically significant difference of incidence of delayed ischaemic deterioration comparing the Nimodipine-reduction group with the normal dose group. This study demonstrates that a considerable risk exists of Nimodipine induced hypotension in intravenous administration despite gradually increasing the doses. Correction of hypotension through further induced hypervolaemia accompanied by vasoactive agents can lead to critical haemodynamic situations. We therefore recommend oral Nimodipine administration.

Administration, Oral↗
PubMed1994

Extreme lateral lumbar disc herniation: clinical presentation in 178 patients.

A retrospective analysis of clinical characteristics of 178 consecutive patients with extreme lateral lumbar disk herniation, amongst 3047 patients operated on for herniated lumbar disc, is presented. The level specific incidence of extreme lateral disc herniation (ELLDH) ranged from a low of 4.5% at L4-5 to peak of 17.4% at L3-4 although the largest number of ELLDH occurred at L4-5 and L5-S1 for a total number of 139 cases (78.1%). 43.6% of all L3 radiculopathies were caused by an L3-4 ELLDH, whereas only 4.4% of all L5 radiculopathies were caused by an L5-S1 ELLDH. Leg pain, either of the sciatic or the femoral type, was the first and dominant clinical symptom of radiculopathy, but pain radiation occurred not always in the appropriate dermatomal segment. ELLDH at upper levels (L2-3 and L3-4) caused usually none or only minor low back signs (76.2%), whereas ELLDH at lower levels more often caused moderate or major lumbar symptoms and signs (59.6%). Positive femoral nerve traction test with upper ELLDH showed a high frequency (84.4%) and reliability and is therefore an important clinical parameter in this situation. Motor deficits occurred more often (78.8%) than sensory deficits (46.6%), were usually of the monoradicular type and were therefore a more reliable clinical sign than sensory disturbances.

Adolescent↗