scholarly journals Retrosigmoid Approach: A Simple and Safe Way to Resect Intrinsic Pontomedullary Lesions

2019 ◽  
Vol 81 (03) ◽  
pp. 223-231
Author(s):  
José M. González-Darder ◽  
Pau Capilla-Guasch ◽  
Luis Real-Peña

Objectives The main objective of this article is to describe a simple and safe protocol for the microsurgical management of ventrally located intrinsic pontomedullary lesions based on the retrosigmoid approach, cortectomy performed utilizing safe entry zones of the pons and medulla, and a delicate microsurgical resection. The intraoperative protocol includes redundant procedures that provide security in decision-making during surgery. Design A prospective series of 11 cases is presented. All patients were studied following the same clinical and imaging workup. A regular retrosigmoid craniotomy surgical approach was utilized. The peritrigeminal area in the pons and the olivary area in the medulla were considered as the safe entry zones. Neuronavigation of the white fiber tracts and electrophysiological monitoring were used as intraoperative aids to locate the lesions, the safe entry zones, and the placement of the cortectomy. Results Six lesions were pontine, two medullary, and the remaining six pontomedullary. Eight lesions were cavernomas, while the remaining three tumors. Overall, we obtained a postoperative functional improvement in the affected cranial nerves in 90.1% of the patients and a total or partial recovery of long ascending or descending pathway symptoms in 72.3% of the patients. All the patients were satisfied with the procedure and the results. Conclusions Radical resection of ventral intrinsic pontomedullary lesions displays a high degree of intraoperative reliability, and a good clinical result is possible using simple surgical procedures. The anatomical references are the first element in the decision-making process during surgery.

2019 ◽  
Vol 18 (2) ◽  
pp. E38-E38
Author(s):  
Benjamin K Hendricks ◽  
Robert F Spetzler

Abstract Brainstem arteriovenous malformations (AVMs) are rare lesions (2%-6% of all intracranial AVMs) that are surgically challenging because of the high eloquence of the brainstem, including dense fiber tracts, cranial nerves, and multiple vital cerebrovascular structures. All these lesions possess eloquence and deep venous drainage, making them innately Spetlzer–Martin grade III or above. This patient had a large midbrain AVM with a complex clinical course beginning with ventriculoperitoneal shunting due to mass effect; the patient experienced 4 hemorrhages, underwent radiation treatment, and finally underwent surgical resection. The surgical approach involved a large torcular craniotomy exposing all posterior sinuses at the confluence. The vein of Galen was exposed and carried deeply to permit ambient cistern opening and relaxation of the cerebellum. Because of earlier radiation therapy, the vessels had undergone hyalinosis, which resulted in difficult manipulation of the nidus but did permit excellent coagulation of the vessels. The complete nidus was removed, as confirmed on postoperative angiography. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.


2018 ◽  
Vol 1 (1) ◽  
pp. 35-42
Author(s):  
Muslimin B ◽  
Sumardi Sumardi

 Interests and number of STMIK Balikpapan new student enrollments are increasing every year. The balance of the ratio of lecturers to students is one of the most important components in improving the quality and teaching and learning process of a university. Avoiding shortages in the number of lecturers can be realized by providing scholarship programs to alumni and teaching assistants. This study aims to build a multi criteria decision making application that can assist the Head of HRD in the process of receiving scholarships to advanced and effective study lecturers. The multi criteria decision making application developed in this study uses the SAW method. The implementation of the SAW method includes the process of evaluating the weighting of criteria, evaluating alternative weights, the matrix process, the results of decision making preferences, resulting in the weighting and ranking of each alternative candidate for the scholarship recipient. The results of the evaluation of multi-criteria application decision making in the study are expected to produce modeling with a high degree of accuracy. The results of the analysis carried out can provide alternative recommendations for prospective scholarship recipients to advanced study lecturers in STMIK Balikpapan.


2019 ◽  
Vol 1 (2) ◽  
pp. V1
Author(s):  
Sima Sayyahmelli ◽  
Jian Ruan ◽  
Bryan Wheeler ◽  
Mustafa K. Başkaya

Primary glioblastoma multiforme tumors of the medulla oblongata are rare, especially in the adult population. Perhaps due to this rarity, we are not aware of any previous reports addressing the resection of these tumors or their clinical outcomes.In this surgical video, we present a 43-year-old man with a 1-month history of left-sided paresthesia. The paresthesia initiated in the left hand, along with weakness and reduced fine motor control, and then spread to the entire left side of the body. He had recent weight loss, imbalance, difficulty in swallowing, and hoarseness in his voice. He also had a diminished gag reflex, and significant atrophy of the right side of the tongue with an accompanying deviation of the uvula and fasciculations of the tongue. MRI showed an infiltrative expansile mass within the medulla with peripheral enhancement and central necrosis. In T2/FLAIR sequences, a hyperintense signal extended superiorly into the left inferior aspect of the pons and left inferior cerebellar peduncle and inferiorly into the upper cervical cord.The decision was made to proceed with surgical resection. The patient underwent a midline suboccipital craniotomy with C1 laminectomy for surgical resection of this infiltrative expansile intrinsic mass in the medulla oblongata, with concurrent monitoring of motor and somatosensory evoked potentials and monitoring of lower cranial nerves IX, X, XI, and XII. A gross-total resection of the enhancing portion of the tumor was performed, along with a subtotal resection of the nonenhancing portion. The surgery and postoperative course were uneventful. Histopathology revealed a grade IV astrocytoma. The patient received radiation therapy.In this surgical video, we demonstrate important steps for the microsurgical resection of this challenging glioblastoma multiforme of the medulla oblongata.The video can be found here: https://youtu.be/QHbOVxdxbeU.


Author(s):  
Pinar E. Ocak ◽  
Selcuk Yilmazlar

Abstract Objectives This study aimed to demonstrate resection of a craniovertebral junction (CVJ) meningioma via the posterolateral approach. Design The study is designed with a two-dimensional operative video. Setting This study is conducted at department of neurosurgery in a university hospital. Participants A 50-year-old woman who presented with lower cranial nerve findings due to a left-sided lower clival meningioma (Fig. 1). Main Outcome Measures Microsurgical resection of the meningioma and preservation of the neurovascular structures. Results The patient was placed in park-bench position and a left-sided retrosigmoid suboccipital craniotomy, followed by C1 hemilaminectomy and unroofing the lip of the foramen magnum, was performed. The dural incision extended from the suboccipital region down to the posterior arch of C2 (Fig. 2). The arachnoid overlying the tumor was incised, revealing the course of the cranial nerve (CN) XI on the dorsolateral aspect of the tumor. The left vertebral artery (VA) was encased by the tumor which was originating from the dura below the jugular foramen. The mass was resected in a piecemeal fashion eventually. At the end of the procedure, all relevant cranial nerves and adjacent vascular structures were intact. Postoperative magnetic resonance imaging (MRI) confirmed total resection and the patient was discharged home on postoperative day 3 safely. Conclusions Microsurgical resection of the lesions of the CVJ are challenging as this transition zone between the cranium and upper cervical spine has a complex anatomy. Since adequate exposure of the extradural and intradural segments of the VA can be obtained by the posterolateral approach, this approach can be preferred in cases with tumors anterior to the VA or when the artery is encased by the tumor.The link to the video can be found at: https://youtu.be/d3u5Qrc-zlM.


2021 ◽  
Author(s):  
Antonio Aversa ◽  
Ossama Al-Mefty

Abstract Chordoma is not a benign disease. It grows invasively, has a high rate of local recurrence, metastasizes, and seeds in the surgical field.1 Thus, chordoma should be treated aggressively with radical resection that includes the soft tissue mass and the involved surrounding bone that contains islands of chordoma.2–5 High-dose radiation, commonly by proton beam therapy, is administered after gross total resection for long-term control. About half of chordoma cases occupy the cavernous sinus space and resecting this extension is crucial to obtain radical resection. Fortunately, the cavernous sinus proper extension is the easier part to remove and pre-existing cranial nerves deficit has good chance of recovery. As chordomas originate and are always present extradurally (prior to invading the dura), an extradural access to chordomas is the natural way for radical resection without brain manipulation. The zygomatic approach is key to the middle fossa, cavernous sinus, petrous apex, and infratemporal fossa; it minimizes the depth of field and is highly advantageous in chordoma located mainly lateral to the cavernous carotid artery.6–12 This article demonstrates the advantages of this approach, including the mobilization of the zygomatic arch alleviating temporal lobe retraction, the peeling of the middle fossa dura for exposure of the cavernous sinus, the safe dissection of the trigeminal and oculomotor nerves, and total control of the petrous and cavernous carotid artery. Tumor extensions to the sphenoid sinus, sella, petrous apex, and clivus can be removed. The patient is a 30-yr-old who consented for surgery.


2022 ◽  
Vol 157 ◽  
pp. 1
Author(s):  
Guilherme H.W. Ceccato ◽  
Júlia S. de Oliveira ◽  
Pedro H.S. Neto ◽  
Nick D. de Carvalho ◽  
Vinícius N. Coelho ◽  
...  

2020 ◽  
Vol 37 (1) ◽  
pp. 1-28
Author(s):  
Stephen C. Craig ◽  
Paulina Cossette ◽  
Michael Martinez

American politics today is driven largely by deep divisions between Democrats and Republicans. That said, there are many people who view the opposition in an overwhelmingly negative light – but who simultaneously possess a mix of positive and negative feelings toward their own party. This paper is a response to prior research (e.g., Lavine, Johnson, and Steenbergen 2012) indicating that such ambivalence increases the probability that voters will engage in "deliberative" (or "effortful") rather than "heuristic" thinking when responding to the choices presented to them in political campaigns. We extend the logic of this argument to a hypothetical race for Congress, using data from a survey experiment to determine whether a high degree of ambivalence toward one's party makes voters more responsive to a negative attack against the candidate of that party. In fact, we find little evidence that partisan ambivalence promotes a deliberative response to negative campaign ads.


2006 ◽  
Vol 58 (suppl_4) ◽  
pp. ONS-189-ONS-201 ◽  
Author(s):  
John Sinclair ◽  
Michael E. Kelly ◽  
Gary K. Steinberg

Abstract Objective: Arteriovenous malformations (AVMs) involving the cerebellum and brainstem are relatively rare lesions that most often present clinically as a result of a hemorrhagic episode. Although these AVMs were once thought to have a more aggressive clinical course in comparison with supratentorial AVMs, recent autopsy data suggests that there may be little difference in hemorrhage rates between the two locations. Although current management of these lesions often involves preoperative embolization and stereotactic radiosurgery, surgical resection remains the treatment of choice, conferring immediate protection to the patient from the risk of future hemorrhage. Methods: Most symptomatic AVMs that involve the cerebellum and the pial or ependymal surfaces of the brainstem are candidates for surgical resection. Preoperative angiography and magnetic resonance imaging studies are critical to determine suitability for resection and choice of operative exposure. In addition to considering the location of the nidus, arterial supply, and predominant venous drainage, the surgical approach must also be selected with consideration of the small confines of the posterior fossa and eloquence of the brainstem, cranial nerves, and deep cerebellar nuclei. Results: Since the 1980s, progressive advances in preoperative embolization, frameless stereotaxy, and intraoperative electrophysiologic monitoring have significantly improved the number of posterior fossa AVMs amenable to microsurgical resection with minimal morbidity and mortality. Conclusion: Future improvements in endovascular technology and stereotactic radiosurgery will likely continue to increase the number of posterior fossa AVMs that can safely be removed and further improve the clinical outcomes associated with microsurgical resection.


Author(s):  
Henry Colle ◽  
David Colle ◽  
Bonny Noens ◽  
Bob Dhaen ◽  
Giovanni Alessi ◽  
...  

Background During resection of intrinsic brain tumors in eloquent areas, particularly under awake mapping, subcortical stimulation is mandatory to avoid irreversible deficits by damaging white fiber tracts. The current practice is to alternate between subcortical stimulation with an appropriate probe and resection of tumoral tissue with an ultrasound aspiration device. Switching between different devices induces supplementary movement and possible tissue trauma, loss of time, and inaccuracies in the localization of the involved area. Objective To use one device for both stimulation as well as a resecting tool. Methods The tip of different ultrasound aspiration devices is currently used for monopolar current transmission (e.g., for vessel coagulation in liver surgery). We use the same circuitry for monopolar subcortical stimulation when connected with the usual stimulator devices. Results We have applied this method since 2004 in over 500 patients during tumor resection with cortical and subcortical stimulation, mostly with awake language and motor monitoring. Conclusion A method is presented using existing stimulation and wiring devices by which simultaneous subcortical stimulation and ultrasonic aspiration are applied with the same tool. The accuracy, safety, and speed of intrinsic intracranial lesion resection can be improved when subcortical stimulation is applied.


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