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Laligam N Sekhar

Publications and source records attributed to Laligam N Sekhar.

At least 19 recordsLinked to original sources
PubMed2006

Endoscopic microneurosurgery: usefulness and cost-effectiveness in the consecutive experience of 210 patients.

OBJECTIVE: Indications, usefulness, and cost-effectiveness of the endoscope in routine microneurosurgery are not clear. To delineate such aspects, we assessed our experience of endoscopic application and additional cost to use an endoscope. METHODS: Endoscopes were used in 210 patients with cranial base and cisternal pathological features in the previous 7 years. Lesions were located in the extradural cranial base in 78 patients and in the cistern in 132 patients. Rigid lens endoscopes 2.7 to 4 mm in width, 11 to 20 cm in length, and 0 to 70 degrees in angle were used. RESULTS: Endoscopes were used for primary or a significant part of the surgery in 64% of the extradural cranial base procedures. Although endoscopes were used only for visual assistance in 82% of cisternal pathological features, significant benefit was noted in 9% and was not different from cranial base lesions. Eleven patients may have had complications if the endoscope had not been used, and 10 procedures would have been impossible without endoscopic use. Therefore, the number of patients need to treat to experience significant benefits by endoscope was 10. Endoscopic equipment costs an additional 326 US dollars per patient and, hence, significant benefit was the equivalent of 3260 US dollars. No permanent complications resulted from the use of the endoscope. CONCLUSION: The endoscope can be applied safely in routine microsurgery with specific equipment and has proven useful in 1 of 10 patients. To perform more effective procedures using endoscopes, we need to develop specially designed instruments usable through a narrow corridor and in an angled field.

Cisterna Magna↗
PubMed2006

Patient outcome at long-term follow-up after aggressive microsurgical resection of cranial base chondrosarcomas.

OBJECTIVE: To evaluate patient clinical outcome and survival at long-term follow-up after aggressive microsurgical resection of chondrosarcomas of the cranial base. METHODS: Over a 20-year period, 47 patients underwent 72 operative procedures for resection of cranial base chondrosarcomas. Thirty-three patients were previously untreated, whereas 14 patients previously had undergone surgery or radiation. Twenty-three patients had a single operation and 24 underwent staged (more than one) operations because of extensive disease. Patients who underwent subtotal resection also underwent radiotherapy or radiosurgery. Patients were evaluated at follow-up clinically and by imaging studies. RESULTS: Gross total resection was accomplished in 29 (61.7%) patients, and subtotal resection was accomplished in 18 patients (38.3%). The resection was better in patients who underwent a primary operation (gross total resection, 68.8 versus 46.7%) rather than a reoperation. Patients who underwent incomplete resection underwent postoperative radiotherapy, which included proton beam radiotherapy (15.6%), radiosurgery (68%), and fractionated radiation (15.6%). There were no operative deaths. Postoperative complications (cerebrospinal fluid leakage, quadriparesis, infections, cranial nerve palsies, etc.) were observed in 10 patients (18%). The follow-up ranged from 2 to 255 months, with an average of 86 months. At the conclusion of study, 36 (76.6%) patients were alive, and 21 (44.7%) patients were alive without disease. Recurrence-free survival was 32% at 10 years in all patients, 42.3% in primary patients and 13.8% in those who underwent reoperation. The Karnofsky performance score was 82.4 +/- 9.8 before surgery, 85 +/- 12.5 at 1 year after surgery, and 85.3 +/- 5.8 at the latest follow-up. Two patients died as a result of radiotherapy complications (malignancy, radiation necrosis). CONCLUSION: Cranial base chondrosarcomas can be managed well by complete surgical resection or by a combination of surgery and radiotherapy. The study cannot comment about the efficacy of radiotherapy. Approximately half of the patients survived without recurrence at long-term follow-up (>132 mo). The functional status of the surviving patients was excellent at follow-up.

Adolescent↗
PubMed2006

Patient outcome at long-term follow-up after aggressive microsurgical resection of cranial base chordomas.

OBJECTIVE: In this study, we evaluated patients' clinical outcome and recurrence rates at long-term follow-up after aggressive microsurgical resection of cranial base chordomas. METHODS: Seventy-four patients with chordomas underwent operations during a 16-year period from 1988 to 2004. The philosophy was to perform complete resection whenever possible and to provide adjuvant radiotherapy for remnants. Staged operations were performed for extensive tumors or if a sizable tumor remnant was noted after the first resection. Patients included primary (previously untreated) and previously operated or irradiated cases. Information was prospectively gathered concerning the patients' neurological condition, Karnofsky Performance Scale score, and tumor status on magnetic resonance imaging scans. RESULTS: There were 47 primarily operated patients (63.5%) and 27 patients (36.5%) who had previously undergone surgery or radiotherapy. A total of 121 procedures were performed in 74 patients. The mean follow-up period was 96 months, with a range of 1 to 198 months. A single stage removal was performed in 41 (55.4%) of the patients and multiple stage removal was performed in 33 (44.5%) of the patients. Gross total removal was accomplished in 53 (71.6%) of the patients, and subtotal resection was accomplished in 21 (28.4%) of the patients. During the follow-up period, 24 (32%) of the patients had no evidence of disease, 37 (50%) of the patients were alive with evidence of disease, 11 (14.8%) of the patients died of disease, and two (2.7%) of the patients died of complications. Recurrence-free survival at 10 years was 31% for the whole group, 42% for the primarily operated patients, and 26% for the reoperation cases (P = 0.0001). The average Karnofsky Performance Scale score was 80 +/- 11.7 preoperatively, 84 +/- 8.9 at the 1-year follow-up, and 86 +/- 12.8 at the last follow-up in surviving patients. No conclusion could be drawn regarding the value of radiotherapy because of the treatment philosophy and the small number of patients. CONCLUSION: Aggressive microsurgical resection of chordomas can be followed by long-term, tumor-free survival with good functional outcome. A more conservative strategy is recommended in reoperation cases, especially after previous radiotherapy, to reduce postoperative complications.

Adult↗
PubMed2005

Reconstruction options for complex middle cerebral artery aneurysms.

OBJECTIVE: To describe techniques of reconstruction for unclippable and uncoilable middle cerebral artery aneurysms. METHODS: A retrospective review was performed of seven patients who underwent eight operations during a 9-year period to treat complex middle cerebral artery bifurcation aneurysms not amenable to direct clipping or endovascular coiling. All preoperative and postoperative clinical and imaging data were reviewed. Follow-up was obtained for all patients via clinic visit and/or telephone. RESULTS: The operative techniques used included saphenous vein graft bypass (n = 1), radial artery graft interposition (n = 2), radial artery patch (n = 1), superficial temporal artery interposition graft (n = 1), superior thyroid artery interposition graft (n = 1), direct reimplantation of branch (n = 1), and reconstruction of trifurcation (n = 1). There was no mortality. Six patients had excellent outcomes with Glasgow Outcome Scale scores of 5, and one patient had a good outcome with a Glasgow Outcome Scale score of 4. CONCLUSION: Techniques for middle cerebral artery reconstruction may remain important and useful in the age of endovascular aneurysm treatment.

Adolescent↗
PubMed2005

Proposed classification of segments of the internal carotid artery: anatomical study with angiographical interpretation.

The nomenclature and borders of the segments of the internal carotid artery (ICA) remain confusing. A classification of segments of the ICA is proposed based on constant anatomical structures, such as the carotid foramen and canal, the petrous bone, the petrolingual ligament (PLL), and the proximal and distal dural rings. The bilateral ICAs were dissected in 15 cadaveric head specimens using different neurosurgical approaches. The bilateral lacerum foramina were studied in five dry skulls. The bilateral segments of the ICA were also examined on carotid angiograms of 10 normal patients and another with the ophthalmic artery originating from the intracavernous portion of the ICA. The present classification divides the ICA into five segments in the direction of the blood flow. The cervical segment is extradural and extracranial, the petrous segment is extradural and intraosseous, the cavernous segment is interdural and intracavernous, the clinoidal segment is interdural and paracavernous, and the cisternal segment is intradural and intracisternal. The ICA did not pass through the lacerum foramen in any specimen. In all specimens, 1/8 to 5/8 of the lacerum foramen was under the deep dural layer of the cavernous sinus. The term 'lacerum segment' as used previously and called the 'trigeminal segment' by us cannot be justified. The PLL is the posterolateral border of the cavernous sinus and the lacerum and trigeminal segments should be included in the cavernous and petrous segments. The ophthalmic artery may originate from the clinoidal ICA, from the cavernous ICA, or from the middle meningeal artery. Instead of using the term 'ophthalmic segment,' the term 'cisternal segment' should be used for the anatomically distinct ICA in the subarachnoid space. This classification should be minimally affected by anatomical variations.

Carotid Artery, Internal↗
PubMed2004

The trigeminal nerve and ganglion: an anatomical, histological, and radiological study addressing the transtrigeminal approach.

BACKGROUND: The transtrigeminal route with splitting of the trigeminal ganglion (TG) is a skull base approach used to expose the posteromedial part of the cavernous sinus (CS), the base of the TG, and the petrolingual ligament (PLL). METHODS: To verify the transtrigeminal approach (TTA), the 3 divisions of the trigeminal nerve (TN), the so-called TG, and the trigeminal root were analyzed anatomically, histologically, and radiologically. The anatomic study was performed bilaterally in 5 cadaveric head specimens. For the histologic study, 6 TN specimens removed from cadavers were used. In addition, the radiologic demonstration of the TN and its so-called ganglion was performed on 5 cases by magnetic resonance imaging (MRI) scan. RESULTS: The TN is composed of linear, crossing, and connecting rootlets. These 3 types of rootlets indicate a plexiform constitution rather than a ganglion even though there are ganglionic cells. Consequently, the term "trigeminal plexus" may be preferred to describe this network. In our new proposed classification, the segments of the TN can be divided into 6 portions according to their relationship with the brainstem, the cisterns, and the bone structures. The first 3 segments before separating into 3 divisions are (1) pontine, (2) cisternal (preganglionic or preplexal), (3) gasserian (ganglionic or plexal). The last 3 segments after the division are (4) preforamino-fissural (postganglionic or postplexal), (5) foramino-fissural, and (6) extracranial (postforamino-fissural). A loose connective tissue along the rootlets of the maxillary and the mandibular divisions of the TN at the gasserian (ganglionic or plexal) segment enabled us to split the so-called "trigeminal ganglion" or "gasserian ganglion" to perform the TTA. CONCLUSION: The TTA is possible, useful, and necessary in selected cases with invasion of the posteromedial part of the CS.

Humans↗
PubMed2004

Endoscope-assisted microsurgery for microvascular compression syndromes.

OBJECTIVE: To discuss the results of endoscope-assisted surgery in microvascular decompression (MVD) of Cranial Nerves (CNs) V, VII, and VIII. METHODS: Neuroendoscopy was used as an adjunct to the surgical microscope in the MVD of the trigeminal (17 patients), facial (10 patients), and vestibulocochlear (1 patient) nerves in a series of 28 consecutive patients. After a standard microsurgical approach to CNs V, VII, and VIII, the endoscope was used to inspect all aspects of neural anatomy, to assess vascular compression, and to check the results of the decompression. Endoscope use was graded in four categories: Grade I, used but no definite role; Grade II, visualization assisted; Grade III, procedure assisted; and Grade IV, primary role. The usefulness of the endoscope was evaluated in each case. RESULTS: The endoscope was useful in visualizing the anatomy in all cases. It was especially useful in establishing trigeminal vein compression of CN V in Meckel's cave; observing multiple sources of vascular compression; ensuring adequate decompression after cauterization of vein, insertion of the Teflon felt, or a pexy procedure; and permitting observation of the compression of CN VII at the root exit zone by small arteries and veins. In six patients with trigeminal neuralgia, the trigeminal vein was cauterized and divided by using endoscopic vision only because the venous compression was not completely visualized with the microscope. During a follow-up period of 6 to 52 months (mean, 29 mo; median, 40 mo), all patients were asymptomatic and receiving no medication. CONCLUSION: The endoscope is a useful adjunct to MVD in the treatment of trigeminal neuralgia, hemifacial spasm, and disabling positional vertigo or tinnitus.

Arterioles↗
PubMed2004

Bypass grafting and revascularization in the management of posterior circulation aneurysms.

OBJECTIVE: To describe the bypass techniques, cranial base approaches, results of treatment, causes of failure, and lessons that are learned in patients with posterior circulation aneurysms requiring revascularization. METHODS: Retrospectively, 19 patients with posterior fossa aneurysms requiring revascularization procedures operated on between 1991 and 2002 were reviewed. Preoperative and postoperative clinical information, neurological examinations, imaging data, and updated follow-ups were reviewed. Patient outcome is reported as the most current Karnofsky Performance Scale score. RESULTS: A total of 22 arterial bypasses were performed in 19 patients for posterior fossa circulation aneurysms between 1991 and 2002. The mean follow-up was 41 months. Total graft patency rate (including patients requiring reoperation) was 86.4% (before) and 100% (after) salvage procedures. Patient outcome was 84.2% with Karnofsky Performance Scale score 80 to 90, and three deaths occurred perioperatively. Only one death could be attributed to the failure of the radial artery graft because of spasm and subsequent rupture during angioplasty. CONCLUSION: Certain graft selection criteria and technical considerations contribute to the success or failure of bypass grafts in the management of posterior circulation aneurysms. Bypass procedures remain an important method of management of complex posterior circulation aneurysms, in addition to endovascular procedures.

Adolescent↗
PubMed2003

Endoscopic and Microscopic Extended Subfrontal Approach to the Clivus: A Comparative Anatomical Study.

Ten cadaveric heads fixed and injected were dissected in the operative position. An enlarged subfrontal approach was adopted. The clival bone was drilled as much as possible under direct microscopic vision. Dissection in blind angles was avoided until the clival dura was exposed. The rigid 4-mm endoscope (angled 0 degrees and 30 degrees) was secured in a holder so the surgical cavity could be inspected. The residual bone was drilled under endoscopic visualization. The amount of bone removed was measured and compared with that removed under microscopic view. Blind angles in both microscopic and endoscopic views were recorded. The additional area of clival bone removed under endoscopic visualization compared with microscopic visualization was 467 mm(2) (range, 176 to 753 mm(2); standard deviation, 208.8 mm(2)).The amount of additional bone removed under endoscopy was inversely and significantly related to the minimal distance between the vertical segment of the two cavernous carotid arteries (p = 0.04). The endoscope is of great value in the removal of clival bone through the extended subfrontal approach. Its use improves the visualization of angles that are blind under the microscope.

Journal Article↗
PubMed2002

The cosmetic aspects of neurosurgery.

The cosmetic aspects of neurosurgery are important and make a considerable difference to the patient's quality of life. In general, the saying is true that "at a cocktail party, the patient should not be recognized as having had neurosurgery, or, even better, the patient's own neurosurgeon should not be able to detect which side the patient was operated on when the patient is seen in the office 6 months later without looking at the chart."

Cranial Nerves↗
PubMed2002

The preservation and reconstruction of cerebral veins and sinuses.

Although cerebral veins and venous sinuses are very important to the neurosurgeon, they have received adequate attention only recently. The consequences of cerebral venous occlusion are well known. When the venous outflow is compromised due to a lack of adequate collateral circulation, venous infarction follows, with swelling, haemorrhage and neuronal death. The clinical consequences will depend upon the region of involvement of the brain and the site of the infarcted tissue. The symptoms may include seizures, hemiplegia, aphasia, coma and death. Similarly, the consequences of cerebral venous sinus occlusion depend upon the availability of collateral circulation. When such collaterals are not available, papilledema and visual loss and a pseudotumour cerebri syndrome are observed in milder cases, whereas, severe diffuse brain swelling, coma and death may be observed in severe cases. Acute venous or venous sinus occlusion is potentially very dangerous, whereas slow and chronic venous or venous sinus occlusion is better tolerated. Even in such patients, some neurological manifestations may follow, when the collaterals are poor.

Adult↗
PubMed2002

Commentary.

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Journal Article↗
PubMed2002

Cutaneous metastasis from an intracranial glioblastoma multiforme.

A 34-year-old white man with a history of an intracranial glioblastoma multiforme was treated with surgical excision and radiotherapy. Five months later, the patient had a rapidly growing scalp mass develop. This lesion was excised, and the histology revealed a tumor that was similar to the originally resected intracranial glioblastoma. Immunohistochemistry for general neuroepithelial derivation (S-100 protein) and for glial fibrillary acidic protein (GFAP) was positive, whereas mesenchymal, epithelial, and neuronal markers were negative. This immunohistochemistry pattern was identical to the original tumor. Although metastasis of this tumor is not uncommon, metastasis to the skin has never been reported. To our knowledge, this is the first reported case of cutaneous metastasis from glioblastoma in the world literature.

Adult↗
PubMed2002

Endoscopic-assisted transcolumellar approach to the clivus: an anatomical study.

OBJECTIVE: Surgical exposure of the clivus and retroclival region is a challenging problem. Several extracranial and intracranial approaches using microsurgical techniques have been proposed in the search to optimize the exposure of the clival region. The objective of the present study was to develop an endoseopic-assisted transcolumellar approach to the anterior clivus. STUDY DESIGN: Experimental anatomic study. METHODS: The approach was studied in 10 consecutive cadaveric preparations. It included a preliminary external rhinoplasty technique with a septal displacement procedure, which gives a wide intranasal route to the posterior wall of the nasopharynx. By use of a drill system and instruments specially designed for endoscopic sinus surgery, the clivus and retroclival region were appropriately managed. Direct morphometric measurements were obtained during all steps of the procedure. RESULTS: The endoscopic-assisted transcolumellar approach developed in the present experimental study allowed a good exposure of the clivus area and anterior cranial-cervical junction. By performing a preliminary septoplasty, the nostrils were turned into a single passage with adequate space for endoscopic insertion and manipulation of one or two instruments. The authors were able to completely expose the posterior wall of the sphenoid sinus and clival dura after the thick bone of the vomer, the floor of the sphenoid, and the clivus were removed by a drill. Angled endoscopes provided a comprehensive view of the retrosellar area. CONCLUSIONS: The endoscopic-assisted transcolumellar approach, besides offering a wide opening for endoscopic management of the clivus, also allowed the surgeon to perform a double-handed procedure and to associate the use of a microscope if needed. The use of endoscopes, although lacking the three-dimensional view, gave a thorough and closer exposure of the surgical field with the advantage of a multiangled perspective.

Brain↗
PubMed2002

Cerebral revascularization for aneurysms and tumors.

OBJECTIVE: To discuss the indications, techniques, pitfalls, complication avoidance, and management of cerebral revascularization techniques for the treatment of aneurysms and cranial base tumors. METHODS: The indications for cerebral revascularization procedures included microsurgical occlusion of a parent vessel during the treatment of aneurysms and occlusion of a major vessel during the treatment of basal tumors. The techniques discussed include arterial patch grafting, end-to-end anastomosis, side-to-side anastomosis, arterial interposition grafting, and extracranial-to-intracranial bypass grafting, using radial artery grafts or saphenous vein grafts. RESULTS: During the 15-year period between 1985 and 2000, the senior author performed 24 radial artery grafts, 105 saphenous vein grafts, and 8 other revascularization procedures, among 50 patients with aneurysms and 83 patients with cranial base tumors. The overall patency rate was 95.6%. Twenty-three patients experienced a cerebral infarction; among those patients, 17 (12.5%) exhibited symptoms but the majority demonstrated considerable recovery during the follow-up period. One hundred one patients recovered to an excellent (Glasgow Outcome Scale score of 5) or good (Glasgow Outcome Scale score of 4) condition. Fifteen patients died as a result of recurrence or progression of tumors during the follow-up period. There were five perioperative deaths. For the last 35 patients, the surgical mortality rate was 0%, with all patients returning to an excellent or good condition. CONCLUSION: Although highly specialized, these sophisticated cerebral revascularization techniques should be learned and practiced by all neurosurgeons who wish to microsurgically treat intracranial aneurysms or cranial base tumors.

Anastomosis, Surgical↗
PubMed2002

Nonvestibular schwannomas of the brain: a 7-year experience.

OBJECTIVE: Nonvestibular schwannomas are uncommon tumors of the brain. Trigeminal nerve schwannomas are the most common of this group, followed by glossopharyngeal, vagal, facial, accessory, hypoglossal, oculomotor, trochlear, and abducens nerve schwannomas, in descending order of frequency. We present a series of nonvestibular schwannomas that were surgically treated during a 7-year period. METHODS: Forty-six patients with schwannomas of Cranial Nerves V (26 cases), VII (7 cases), IX, X, and XI (9 cases), XII (3 cases), and III (1 case) were microsurgically treated by the senior author (LNS) during a 7-year period, from 1993 to 2000. The clinical presentations, operative approaches, complications, and results were studied. RESULTS: Forty-five patients underwent gross total tumor resection in the first operation. One patient who had undergone subtotal tumor resection in the initial operation experienced a large recurrence after 4 years, and gross total tumor resection was achieved in the second operation. There were no postoperative deaths. Postoperative morbidity consisted of cerebrospinal fluid leaks for 5 patients (3 patients required a second operation to repair the leak, and 2 patients responded to lumbar drain placement), meningitis for 3 patients (2 cases were aseptic and 1 involved bacterial meningitis, which resolved with antibiotic therapy), vasospasm requiring angioplasty for 1 patient, temporary hemiparesis for 2 patients (who experienced good recoveries), and permanent hemiparesis for 1 patient. New cranial nerve deficits were observed for 24% of patients but were usually partial. The mean follow-up period was 33.3 months (range, 0.2-93 mo). No patient experienced tumor recurrence after complete tumor removal. The patient who experienced regrowth of the tumor did not exhibit recurrence after the second operation. The Karnofsky Performance Scale scores at the latest follow-up examination were 80 or more for 45 patients (98%) and 70 for 1 patient. CONCLUSION: Nonvestibular schwannomas can be treated via microsurgical excision, with excellent functional results. Recurrence is rare after total tumor excision, although much longer follow-up monitoring is required.

Adolescent↗
PubMed2002

Patient-evaluated outcome after surgery for basal meningiomas.

OBJECTIVE: To study the outcomes of patients with basal meningiomas treated by one primary surgeon with a philosophy of aggressive surgical management to establish an index of satisfaction and patient-evaluated outcome. METHODS: We collected prospective data for patients with basal meningiomas who were operated on by one primary surgeon (LNS) during a 7-year period from 1993 to 2000. The outcomes in 269 patients were ascertained through follow-up visits, mailed follow-up questionnaires, and telephone interviews by two other surgeons (RA and MN). The mean patient age was 50 +/- 13.6 years. The mean estimated tumor diameter was 3.07 +/- 1.24 cm. There were 62 males and 207 females. Mean follow-up was 49 +/- 26 months. Twenty-seven percent of patients were Levine-Sekhar (LS) Grade 0, 43% were LS Grade I, 24% were LS Grade II, and 6% were LS Grade III. Gross total resection was achieved in 66% of patients. Extent of resection correlated (P < 0.05) with LS grade. Thirty-seven patients received adjuvant treatments, and six patients required reoperations. Perioperative mortality was 1.1%. Eighty percent of patients were discharged home, 17% were discharged to rehabilitation facilities, and 1.5% were discharged to nursing homes. Postoperative complications were observed in 30% of patients. RESULTS: During the follow-up study, of a total of 269 patients, 30 patients could not be contacted, and 11 patients had died of unrelated causes. The mean follow-up Karnofsky Performance Scale score of the patients was 83 +/- 10. Ninety-seven percent of patients were very satisfied/satisfied with their treatments (P < 0.001). Forty-three percent of patients were employed, and 83% of patients were employable. Their expectations of treatment were met in 90% of patients (P < 0.001), 95% thought surgery had been a good treatment choice (P < 0.001), and 95% would recommend the same treatment for a family member (P < 0.001). CONCLUSION: These results demonstrate that patient satisfaction can remain high and satisfactory outcome can be achieved with surgical management in patients with these complex lesions.

Adult↗