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Biomedical subjects

C N Sen

Publications and source records attributed to C N Sen.

At least 19 recordsLinked to original sources
PubMed1996

Surgical treatment of meningiomas involving the cavernous sinus: evolving ideas based on a ten year experience.

The outcomes of 114 patients with meningiomas operated at the University of Pittsburgh were analyzed. Cerebrospinal fluid leakage was the most frequent complication, observed in 25 patients (21%). Complications were more frequent in patients who had recurrent (previously operated) tumors and patients with extensive tumors. Our current analysis also indicates that patients with prior radio-therapy (usually external beam) have unacceptably high complication rates after microsurgery. Early results indicate that regrowth rates are much higher in patients with incomplete resection (20%) than those with gross total excision (5%). Of the 114 patients, 108 returned to independent living and/or their previous occupation.

Cavernous Sinus↗
PubMed1996

Intracerebral hemorrhage occurring remote from the craniotomy site.

OBJECTIVE: The purpose of this study was to analyze the available clinical data on postoperative intracerebral hemorrhages that occur in locations remote from the sites of craniotomy. METHODS: The findings of 37 cases of postoperative intracerebral hemorrhages occurring remote from the craniotomy sites were reviewed (5 from our records and 32 from the literature). RESULTS: Remote postoperative intracerebral hemorrhages presented within the first few hours postoperatively in 78% of the patients and were not related to the types of lesions for which the craniotomies were performed. Supratentorial procedures that produced infratentorial hemorrhages involved operations in the deep sylvian fissure and paraclinoid region in 81% of the patients and hemorrhages in the cerebellar vermis in 67% of the patients. Infratentorial procedures that produced supratentorial hemorrhages were performed with the patient in the sitting position for 87% of the patients. The remote supratentorial hemorrhages that occurred were superficial and lobar in 84% of the patients, as opposed to deep and basal ganglionic, which are classic locations for hypertensive hemorrhages. Remote intracerebral hemorrhages occurring after craniotomies were not associated with hypertension, coagulopathy, cerebrospinal fluid drainage, or underlying occult lesions. These hemorrhages commonly led to significant complications; 5 of 37 patients (14%) were left severely disabled, and 12 of 37 patients (32%) died. CONCLUSIONS: Remote intracerebral hemorrhage is a rare complication of craniotomy with significant morbidity and mortality. Such hemorrhages likely develop at or soon after surgery, tend to occur preferentially in certain locations, and can be related to the craniotomy site, operative positioning, and nonspecific mechanical factors. They do not seem to be related to hypertension, coagulopathy, cerebrospinal fluid drainage, or underlying pathological abnormalities.

Adult↗
PubMed1995

The results of surgery for benign tumors of the cavernous sinus.

CAVERNOUS SINUS SURGERY has been performed increasingly in the last 2 decades because of new knowledge and technologies. With increasing international expertise in cavernous sinus surgery, the results must be analyzed critically to search for accurate prognosticators of outcome. We performed a retrospective review of 124 patients (40 male, 84 female; mean age, 45 years) who underwent cavernous sinus surgery for benign tumors from 1983 to 1992. Sixty-five percent had tumors encasing the internal carotid artery. Mean follow-up was 29 months (median, 26 mo). Gross total or near-total resection was possible in 80%. Patients with neurilemomas, angiofibromas, epidermoids, chondroblastomas, and hemangiomas were more likely to have total or near-total resection (100% versus 75%, P < 0.025). Disabling complications (five cerebral infarctions, two meningitis, and one hydrocephalus with chiasmal prolapse) occurred only in patients with meningiomas or pituitary adenomas. On follow-up, excellent/good binocular vision was achieved in 53% of patients entering surgery with excellent/good function versus 25% who entered surgery with fair/poor binocular vision (P < 0.025). Ninety-three percent of patients had a Karnofsky score > or = 70 on follow-up. There were a total of 12 recurrences (10%), 6 in patients with meningiomas, 2 in patients with angiofibromas, 2 in patients with craniopharyngiomas, 1 in a patient with a pituitary adenoma, and 1 in a patient with an osteoblastoma. Patients with tumor growth or neurological symptoms indicative of progressive cavernous sinus involvement should undergo cavernous sinus exploration. This surgery has acceptable morbidity and mortality and, if the tumor can be removed easily, the surgeon should try to perform radical tumor resection. To avoid major complications, the surgeon must exercise utmost care to preserve the neurovascular structures of the cavernous sinus, with special attention to tumors that extend into the petroclival region. Better results from surgery can be expected in those patients with neurilemomas, hemangiomas, or epidermoids than in patients with meningiomas, craniopharyngiomas, or pituitary adenomas. Good functional outcome can be expected, particularly if the patient's preoperative clinical status is good. Particular attention must be paid to the reconstruction of anatomic barriers in order to prevent cerebrospinal fluid leakage and subsequent meningitis.

Adult↗
PubMed1993

Chordomas and chondrosarcomas involving the cavernous sinus: review of surgical treatment and outcome in 31 patients.

During the last 9 years, 31 patients with chordomas (20 cases) and chondrosarcomas (11 cases) involving the cavernous sinus have been treated using an aggressive surgical approach. On the basis of postoperative magnetic resonance imaging (MRI), 17 patients were considered to have undergone total removal, whereas in the remaining 14 cases the tumor was either subtotally or partially removed. Surgical complications were most commonly encountered among patients who had undergone previous operations. One patient died 3 months after the operation as a result of pulmonary embolism. Significant disability occurred in one patient because of thalamic perforator occlusion and hemorrhage. Recovery of extraocular muscle function was gratifying, and correlated to the preoperative functional level. After a median follow-up of 24 months, three recurrences (21%) occurred among the 14 patients who had undergone incomplete removal. No recurrence was observed among the 17 patients with total resection. This experience shows that gross radical removal of chordomas and chondrosarcomas involving the cavernous sinus can be accomplished with an acceptable surgical morbidity. However, much longer follow-up will be required to determine whether such aggressive surgical treatment results in cure or long-term control of these neoplasms.

Adolescent↗
PubMed1993

Facial nerve management in cranial base surgery.

This study reviewed 124 patients who required facial nerve manipulation during cranial base surgery. Most of them underwent only nerve displacement or selective transection for improved surgical access to the cranial base (70 and 34, respectively). Fourteen patients had the facial nerve resected for oncologic reasons and repaired with primary nerve grafting. Most patients regained quite satisfactory facial function with quality correlating with the degree of nerve injury. Six patients had facial nerve resected as part of oncologic palliation and had the facial deficit rehabilitated with regional tissue. A correlation between preoperative facial nerve weakness and the quality of nerve graft function was not found. An oncologic correlation, however, is suggested (patients with preoperative weakness had less favorable prognosis). Overall, patients who require facial nerve resection for oncologic reasons do not do as well as those with normal preoperative function.

Electric Stimulation↗
PubMed1993

Meningiomas involving the cavernous sinus: value of imaging for predicting surgical complications.

OBJECTIVES: The purpose of this study was to determine if it is possible to predict complications of surgery on cavernous sinus meningiomas on the basis of preoperative MR and CT findings. MATERIALS AND METHODS: We retrospectively reviewed the CT, MR, and postoperative clinical findings in 65 consecutive patients with pathologically proved cavernous sinus meningiomas who had surgery during the period 1985-1991. Tumors were categorized on the basis of their relationship to the cavernous carotid artery. The presence of tumor in three anatomic sites (the sella, the sphenoid sinus, and the orbital apex) was also correlated with surgical complications. RESULTS: Category 1 tumors, which do not completely encircle the cavernous carotid artery, were dissected without injury, sacrifice, or grafting of the artery in 91% of cases. Category 2 lesions completely encircle the artery but do not narrow its lumen; they could be dissected from the cavernous carotid artery without arterial injury in 61% of cases, but imaging failed to discriminate differences within this group. Category 3 lesions, which completely encircle and narrow the cavernous carotid artery, are usually difficult to dissect free from the artery. The categories also correlated with recovery of extraocular motility; 84% of category 1 lesions compared with only 36% of category 2 or 3 lesions will recover to good or excellent extraocular motility after cavernous sinus surgery. Tumor involvement of the sella, orbital apex, and sphenoid sinus correlated with postoperative endocrine dysfunction, decreased visual acuity, and CSF leak, respectively. CONCLUSION: Imaging studies can frequently predict the difficulty of resecting cavernous sinus meningiomas from the cavernous carotid artery and the likelihood of permanent loss of extraocular motility after surgery on these lesions. This information is helpful in appropriate preoperative planning and in providing information to patients about to undergo such surgery.

Carotid Artery Injuries↗
PubMed1992

The extended frontal approach to tumors of the anterior, middle, and posterior skull base.

The extended frontal approach is a modification of the transbasal approach of Derome. The addition of a bilateral orbitofrontal or orbitofrontoethmoidal osteotomy improves the exposure of midline lesions of the anterior, middle, and posterior skull base, while minimizing the need for frontal lobe retraction. The authors present a 5-year experience with 49 patients operated on via the extended frontal approach. In seven patients, the extended frontal approach was used alone; in the remaining 42, it was combined with other skull base approaches. Highly malignant tumors were removed en bloc, whereas benign tumors and low-grade malignancies were removed either en bloc or piecemeal. Reconstruction was usually performed using fascia lata, a pericranial flap, and/or autologous fat. A temporalis muscle flap or a distant microvascular free flap was required for some patients. One patient died 1 month postoperatively due to superior mesenteric artery thrombosis. Three patients had postoperative infections, two had cerebrospinal fluid leaks requiring reoperation, and four had brain contusions or hematomas. All but two patients recovered to their preoperative functional level. After an average follow-up period of 26 months (range 6 to 56 months), 64% of patients with benign lesions, 64% of patients with low-grade malignancies, and 44% of patients with high-grade lesions were alive with no evidence of disease.

Adolescent↗
PubMed1992

Reconstruction of the third through sixth cranial nerves during cavernous sinus surgery.

Sixteen reconstruction procedures of the third through sixth cranial nerves were carried out in 14 patients during operations on 149 tumors involving the cavernous sinus. A direct end-to-end anastomosis was performed in five nerves, whereas in 11 cases the nerve stumps were bridged by means of an interposing nerve graft. The sixth cranial nerve was most frequently reconstructed (nine cases). In four cases, the fifth nerve or root was repaired. The third nerve was reconstructed in two patients, and the fourth nerve was repaired in only one case. Recovery of function, either partial or complete, was observed in 13 nerves: the third in two instances, the fourth in one, the fifth in three, and the sixth in seven. No return of function occurred in three nerves. In patients with a successful recovery of cranial nerve function, either binocular function or the cosmetic result was improved. These results suggest that repair of the third through sixth cranial nerves injured during surgery should be pursued in suitable patients.

Abducens Nerve↗
PubMed1991

Management of tumours involving the cavernous sinus.

The operative experience with 137 tumours of the cavernous sinus at the University of Pittsburgh during the past 7 years is reported. The importance of the normal and tumour-infiltrated cavernous sinus anatomy and imaging is delineated. 63% of the tumours are benign, primarily meningiomas, for which an anatomical grading system is presented. The various operative approaches to the cavernous sinus are described. 88% of the meningiomas were totally resected. There was a 1.5% operative mortality and 1.5% severe morbidity rate. Initial ipsilateral opthalmoplegia progressively improved in the majority of patients. For all patients with at least 6 months of follow up of benign tumours, the intracavernous tumour recurrence rate was 3% and total recurrence rate was 6%.

Brain Neoplasms↗
PubMed1991

Extradural petrous bone and petroclival neoplasms.

Extradural petroclival tumours are composed of a spectrum of histological and anatomical configurations dictating a variety of surgical approaches. The experience with 68 such tumours operated at the University of Pittsburgh is presented, emphasizing the basal subfrontal and lateral approaches. 85% of these tumours are benign or low-grade malignancies, with 62% of these totally resected, resulting in a 5.4% recurrence rate. The operative mortality was 1.5% and major morbidity 3%. Well-planned surgery based on precise anatomical knowledge and imaging is the basis of treatment for petroclival tumours.

Combined Modality Therapy↗
PubMed1991

Facial translocation approach to the cranial base.

Facial translocation is a new approach which has been developed for surgical management of extensive lesions of the anterolateral cranial base, including the nasopharynx, sphenoid sinus, clivus, infratemporal fossa, superior orbital fissure, and cavernous sinus. Temporary displacement of the craniofacial skeleton allows direct, wide access to this complex anatomic area, while giving the surgeon a high degree of control over critical neural and vascular structures.

Adolescent↗
PubMed1991

Midfacial split for access to the central base.

The technique of the midfacial split for access to the central cranial base is described. It provides--using bilateral facial osteotomies and soft tissue mobilization--a unified surgical field extending in the sagittal plane from the anterior cranial fossa floor and sphenoid sinus to the level of the fourth cervical vertebral body. In the axial plane, the periphery of the surgical access may extend to the jugular fossae and the hypoglossal canals. Experiences and results in eight patients are presented.

Chondrosarcoma↗
PubMed1991

Surgical management of anteriorly placed lesions at the craniocervical junction--an alternative approach.

Lesions ventral to the neuraxis at the craniocervical junction can pose a significant management problem because of their strategic location. Conventional posterolateral approaches sometimes may not permit adequate visualization of the entire base of the tumor without significant manipulation of the brain stem and spinal cord. The anterior transoral and extrapharyngeal approaches are alternate ways of exposing this region without neural retraction. However, these approaches do not provide adequate exposure of the lateral margins of the tumour, there is no control of the vertebral arteries and cranial nerves and the tumor--brain stem interface is not seen till the end of the operation. A lateral approach is described in this report which involves additional bone removal in the region of the mastoid process and the articular pillars in order to provide a true lateral perspective for the removal of these tumors. The advantages include excellent definition of the interface between the tumor and cord/brain stem without manipulation of the neuraxis, control of the ipsilateral vertrebral artery and caudal cranial nerves, ability to remove the intra- and extradural portions of the tumor in one operation and the ability to perform an immediate bony fusion if necessary. The application of this approach in the management of 9 patients with a variety of intra- and extradural lesions at the clivus and foramen magnum is discussed.

Adolescent↗
PubMed1991

The transoral approach for the management of intradural lesions at the craniovertebral junction: review of 7 cases.

The main difficulty in dealing with intradural lesions located ventrally in the region of the craniovertebral junction (CVJ) is related to their relative inaccessibility. Posterolateral approaches involve some manipulation of the brain stem and provide limited access because of the necessity of working between the cranial nerves. Even then, the view of the ventral midline and across is limited. The transoral approach, which has been widely used for the management of extradural lesions in this area, is also useful for the treatment of intradural lesions. It provides an unimpeded although somewhat restricted, view of the ventral aspect of the CVJ without the need for brain retraction. The cranial nerves and vertebral arteries are not interposed between the surgeon and the lesion. The risks of cerebrospinal fluid leakage and infection are greatly diminished by the use of fibrin adhesive and prolonged diversion of the cerebrospinal fluid. The use of this approach, together with its technical difficulties and results, in the management of seven purely intradural lesions located ventrally at the CVJ, is discussed.

Adult↗
PubMed1991

Carotid and cranial nerve reconstruction after removal of cavernous sinus lesions.

During the last 7 years, approximately 170 neoplasms, and 35 vascular lesions involving the cavernous sinus were treated by the first two authors. During the treatment of such lesions, the direct vein graft reconstruction of the internal carotid artery from the petrous to the supraclinoid or infraclinoid ICA was performed in 23 patients. Graft occlusion occurred in 3 patients and in one of these, it was successfully salvaged by placing a long venous graft from the extracranial ICA to the M3 segment of the middle cerebral artery. The latter 3 patients were neurologically normal. One patient with significant atherosclerotic disease suffered the dissection of the distal internal carotid artery with the graft being patent. The suturing technique. This patient eventually died. Two patients with severely compromised collateral circulation suffered minor strokes due to the temporary occlusion of the ICA. This has been avoided in the more recent patients by the adoption of brain protection techniques such as moderate hypothermia, induced hypertension, and barbiturate coma. Low dose heparin therapy during grafting and high dose intravenous steroids prior to the grafting also appear to be beneficial. Direct vein graft reconstruction of the intracavernous carotid artery is a valuable tool during the management of cavernous sinus lesions. The advantages and disadvantages of this technique as well as the pros and cons of other revascularization techniques will be discussed. During microsurgical removal of cavernous sinus lesions, the cranial nerves III-VI were reconstructed by direct resuture or by nerve grafting in 16 patients. In the majority of these patients, recovery of cranial nerve function was observed, which was very encouraging.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Arteries↗
PubMed1991

Facial translocation for cranial base surgery.

The complexity of cranial base surgery is a reflection of skull base anatomy as well as technical demands for maximum visualization, control of essential structures, adequate tumor resection and/or reconstruction. Facial translocation has been developed as a new approach to cranial base. It consists of extensive modular facial disassembly which includes displacement of composite facial soft tissue flap and craniofacial skeleton. It creates surgical field with epicenter in nasopharynx and infratemporal fossa allowing easy expansion into sphenoid bone and cranial fossae as well as craniovertebral junction. Reconstruction is functional and esthetic. Versatility of this approach permits expansion into neighboring craniofacial regions. During a 14-month period (11/88-12/89), this facial translocation approach to cranial base was utilized in 20 patients. The approach provided excellent visualization of the involved cranial base permitting oncological as well as reconstructive procedures. All patients healed primarily. Two patients were reoperated on at 4 and 6 months postoperatively; one for a bone graft infection and the other for tumor recurrence. The facial translocation approach offers favorable exposure of the critical zones of cranial base resulting in increased surgical safety and benefit of cranial base surgery.

Adolescent↗
PubMed1991

Craniofacial disassembly in the management of skull-base tumors.

Craniofacial disassembly now plays a major role in the management of tumors that invade the skull base. The chief advantage of this technique is the greatly improved operative exposure it provides, allowing the surgeon to resect such tumors more completely and with an added margin of safety. Microneurosurgical advances have made it possible to preserve cranial nerve function in many cases, and modern reconstructive methods employing vascularized flaps have helped to reduce postoperative complications and deformity. Through the combination of craniofacial techniques and oncologic principles, the outlook for patients with skull base tumors is improving.

Adult↗