CRANIOPLASTY WITH DIRECT REVASCULARIZATION IN HEMORRHAGIC MOYAMOYA DISEASE: 2-DIMENSIONAL OPERATIVE VIDEO.

Moyamoya disease is a progressive nonatherosclerotic stenosis of the terminal segments of the arteries of the Circle of Willis. Hemorrhagic presentation is a life-threatening condition, associated with an increased risk of rebleeding and ischemic events.1-7 We present the case of a 65-year-old woman with a right intracerebral hemorrhage who underwent emergency hematoma evacuation without bone flap replacement. The investigation confirmed the diagnosis of Moyamoya disease and demonstrated hypoperfusion of the right cerebral hemisphere. Late angiography depicted no transdural collaterals through the bone defect and demonstrated preservation of the superficial temporal artery (STA). Next, it was chosen to perform one-stage cranioplasty with direct revascularization. We detached the temporal fascia from the muscle and created a window through the fascia to give STA passage in a corridor through the temporal muscle until the brain's surface. Vascular anastomosis was performed with an interrupted suture line employing a 10-0 nylon thread. Flow within the right middle cerebral artery (MCA) was retrograde, coming from branches of the posterior cerebral artery (PCA), and the end-to-side anastomosis was placed to orientate the STA flow in the same direction as in the MCA. We used a custom-made titanium plate for the cranioplasty and gave enough room inferiorly for the course of STA. In the end, we sutured the temporal fascia to the titanium plate for a better cosmetic result. To avoid additional unnecessary procedures, the performance of direct revascularization during the cranioplasty is feasible and deserves additional investigation as a tool to prevent new hemorrhagic or ischemic events. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Two-Stage Pulsatile Human Placenta Model for Microvascular Anastomosis Training in Neurosurgery.

OBJECTIVE: The development of microsurgical skills is crucial for neurosurgical education. The human placenta is a promising model for practicing vascular anastomosis due to its similarities with brain vessels. We propose a 2-stage model for training in extracranial-to-intracranial anastomosis using the placenta. METHODS: Initially, we propose practicing anastomosis in 2 adjacent placentas. Once successful, the procedure advances to a more challenging configuration that employs a 3-dimensionally printed skull with a window simulating a pterional craniotomy. It is positioned an intracranial placenta and an extracranial one, and the latter has a prominent vessel exposed toward the side of the craniotomy. Both placentas have one artery and vein cannulated in the umbilical cord, and we present an artificial placental circulation system for microvascular training that regulates pulsation and hydrodynamic pressure while keeping veins engorged with a pressurized bag. To verify anastomosis patency, we utilize sodium fluorescein and iodine contrast. RESULTS: The 2-stage model simulated several aspects of microvascular anastomosis. Our perfusion system allowed for intraoperative adjustments of hydrodynamic pressure and pulsation. Using iodine contrast and fluorescein enabled proper evaluation of anastomosis patency and hydrodynamic features. CONCLUSIONS: Training in the laboratory is essential for developing microsurgical skills. We have presented a model for microvascular anastomosis with artificial circulation and postoperative imaging evaluation, which is highly beneficial for enhancing the learning curve in microvascular procedures.

Transmastoid/Infralabyrinthine Approach to the Jugular Foramen: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and variable bony destruction. 1,2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Jugular foramen paragangliomas are complex lesions that usually invade and fill related venous structures. They present complex relationships with skull base neurovascular structures as internal carotid artery, lower cranial nerves (CNs), middle ear, and mastoid segment of facial nerve. In this way, it is essential to perform an adequate preoperative vascular study to evaluate sinus patency and the tumor blood supply, besides a computed tomography scan to depict bone erosion. ESSENTIAL STEPS OF THE PROCEDURE: Mastoidectomy through an infralabyrinthine route up to open the lateral border of jugular foramen, allowing exposure from the sigmoid sinus to internal jugular vein. Skeletonization of facial canal without exposure of facial nerve is performed and opening of facial recess to give access to the middle ear in way of a fallopian bridge technique. 2-10. PITFALLS/AVOIDANCE OF COMPLICATIONS: If there is preoperative preservation of lower CN function, it is important to not remove the anteromedial wall of the internal jugular vein and jugular bulb. In addition, facial nerve should be exposed just in case of preoperative facial palsy to decompress or reconstruct the nerve. VARIANTS AND INDICATIONS FOR THEIR USE: Variations are related mainly with temporal bone drilling depending on the extensions of the lesion, its source of blood supply, and preoperative preservation of CN function.Informed consent was obtained from the patient for the procedure and publication of his image.Anatomy images were used with permission from:• Ceccato GHW, Candido DNC, and Borba LAB. Infratemporal fossa approach to the jugular foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.• Ceccato GHW, Candido DNC, de Oliveira JG, and Borba LAB. Microsurgical Anatomy of the Jugular Foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.

Improvement of optic nerve pial blood supply visualized through indocyanine green videoangiography after resection of a tuberculum sellae meningioma: 2-dimensional operative video.

Ischemia of the optic nerve (ON) is an important cause of visual field deficit provoked by tuberculum sellae (TS) meningiomas. Indocyanine green (ICG) videoangiography could provide prognostic information. Moreover, it allows new insight into the pathophysiology of visual disturbance. The authors present the case of a 48-year-old woman with visual field impairment. Magnetic resonance imaging (MRI) depicted a lesion highly suggestive of a TS meningioma. Following microsurgical resection, ICG videoangiography demonstrated improvement of right ON pial blood supply. In this case, there was one lesion causing visual impairment through both direct compression over the left ON and ischemia to the right nerve. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21155.

Microsurgical Resection of Giant Petroclival Meningioma via the Posterior Petrosal Approach: 2-Dimensional Operative Video.

Petroclival meningiomas are challenging deep-seated lesions related to many critical neurovascular structures of the skull base.1-5 We present the case of a 45-year-old male presenting with a 3-year history of progressive headache associated gradually with multiple cranial nerves deficits and progressive tetraparesis leading to use of a wheelchair (Video 1) Preoperative magnetic resonance imaging demonstrated a mass highly suggestive of a giant left petroclival meningioma. Considering worsening of symptoms and impressive mass effect, microsurgical resection employing the posterior petrosal approach was performed. Mastoidectomy with skeletonization of semicircular canals and a craniotomy approaching both posterior and middle cranial fossae were done. Dural incision at the base of the temporal lobe was communicated to other incision in the presigmoid dura by ligation and sectioning of superior petrosal sinus. Tentorium was cut all the way toward the incisura, with attention to preserve the fifth nerve along its division and fourth nerve in the last cut. After a complete tentorium incision, the presigmoid space enlarged, exposing both supratentorial and infratentorial spaces. The lesion was totally resected employing microsurgical techniques. Postoperative magnetic resonance imaging demonstrated complete tumor resection. The patient experienced improvement of complaints and no new neurologic deficit on follow-up. The posterior petrosal approach gives great exposure and a more lateral angle of attack to the ventral surface of brainstem, allowing in this case to approach the whole tumor attachment. Informed consent was obtained from the patient for the procedure and publication of this operative video. Anatomic images were courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.

Microsurgical Resection of Trigeminal Schwannoma via Anterior Petrosal Approach: 2-Dimensional Operative Video.

Trigeminal schwannomas are complex lesions that may be related to many critical neurovascular structures. We present the case of a 59-year-old male presenting a history of left-sided trigeminal neuralgia. Preoperative imaging demonstrated a mass highly suggestive of a trigeminal schwannoma, and microsurgical resection was indicated considering the progressive symptomatology and important mass effect (Video 1). A middle fossa route including an anterior petrosectomy was chosen. The patient was placed supine with the head rotated to the contralateral side, and an arcuate incision was performed. A V-shaped zygomatic osteotomy was done to mobilize the temporalis muscle more inferiorly and better expose the middle fossa floor. Following craniotomy, peeling of the dura propria from the lateral wall of cavernous sinus was carried out starting by coagulation of middle meningeal artery. Some tumor was already identified and removed, and then the anterior petrosectomy was performed until we exposed the posterior fossa dura. The middle fossa dural incision was connected with the other one at the posterior fossa dura, by coagulation of the superior petrosal sinus. The tentorium was completely cut toward the incisura. After lesion debulking, the tumor was progressively removed by peeling the arachnoid from the lesion to maintain arachnoid planes and preserve the nerves and their blood supply. Postoperative imaging demonstrated complete tumor resection. The patient's symptoms improved, and there were no neurologic deficits on follow-up. Extensive laboratory training is fundamental to be familiarized with the normal anatomic nuances and prepared to face the anatomy distorted by lesion. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Microsurgical Resection of Intracanalicular Vestibular Schwannoma via Retrosigmoid Approach: 3-Dimensional Operative Video.

Vestibular schwannomas are a multifaceted group of tumors that can present with different sizes and involvement of critical neurovascular structures.1-6 While operating on these tumors, a critical goal is postoperative preservation of facial nerve function and hearing. We present the case of a 66-year-old male with a history of severe left-sided tinnitus and progressive hearing loss (Video 1). Preoperative imaging depicted a lesion highly suggestive of an intracanalicular vestibular schwannoma. Due to worsening of symptoms and after thoughtful discussion with the patient, microsurgical resection was indicated under constant neurophysiologic monitoring. A retrosigmoid approach was employed, and the posterior wall of the internal auditory canal was opened, allowing exposure of tumor and its total resection. Postoperative imaging demonstrated complete tumor resection. The patient's symptoms improve, and there were no new neurologic deficits on follow-up. Anatomical images were a Courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Education Foundation (NREF).

Microsurgical Resection of Petroclival Meningioma via the Posterior Petrosal Approach: Three-Dimensional Operative Video.

Petroclival meningiomas are complex, deep-seated lesions related to many critical neurovascular structures. We present the case of a 44-year-old woman who had presented with a history of severe facial pain, hearing loss, and tinnitus on the left side, associated with left facial hypoesthesia (Video 1). Preoperative magnetic resonance imaging demonstrated a mass highly suggestive of a left petroclival meningioma. Considering the worsening symptoms and important mass effect, microsurgical resection using the posterior petrosal approach was performed. Mastoidectomy was performed first, followed by craniotomy encompassing both posterior and middle cranial fossae. The posterior fossa and middle fossa dural incisions were connected, coagulating and sectioning the superior petrosal sinus. Next, the tentorium was cut all the way toward the incisura, with care to preserve the fourth nerve in the last cut. After completion of the tentorium incision, the presigmoid space increased. The lesion was totally resected using microsurgical techniques, with the aid of an ultrasonic aspirator to debulk the mass and allow for its circumferential dissection. Postoperative magnetic resonance imaging demonstrated complete tumor resection. The patient presented with improvement of symptoms and no new neurological deficit during follow-up. Skull base approaches, such as the posterior petrosal approach, are useful for successfully treating challenging lesions such as the one presented, with low morbidity. Laboratory training is essential to be familiarized with the complex intraoperative neuroanatomical nuances. The patient provided written informed consent for the report of her case and operative video. The anatomical images were provided courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.

Multimodal treatment of a pediatric posterior fossa arteriovenous malformation employing endovascular and microsurgical techniques.

Intracranial hemorrhage is the most common presentation of posterior fossa arteriovenous malformations (AVMs) and may have serious consequences. The authors present a case of a 7-year-old girl with headache, vomiting, dysmetria, and ataxia due to a ruptured cerebellar grade III AVM. After two sessions of embolization, the patient underwent total microsurgical resection through a suboccipital craniotomy. There were no additional postoperative deficits, and the patient improved progressively during 6 months of rehabilitation. These challenging lesions should be removed after rupture, especially in children with long-term cumulative risk of rebleeding. Multimodal treatment reduces the perioperative bleeding, allowing better outcomes for pediatric AVM. The video can be found here: https://youtu.be/HQWnjD8ENZQ.

Use of Superior Petrosal Venous Complex to Transpose the Superior Cerebellar Artery in Microvascular Decompression for Trigeminal Neuralgia: 2-Dimensional Operative Video.

Trigeminal neuralgia is a cause of severe facial pain, usually provoked by a neurovascular conflict, commonly involving the superior cerebellar artery (SCA).1 The superior petrosal venous complex is in the way toward the nerve through a retrosigmoid approach and can narrow the working area around trigeminal nerve.2-4 Nonetheless, instead an obstacle it can be faced in selected cases as an adjunct to help to transpose the offending arterial loop, avoiding undesired venous sacrifice. We present a case of a 64-year-old man with left-sided severe shock-like pain in the V3 territory suggestive of trigeminal neuralgia (Video 1). Preoperative imaging depicted a neurovascular conflict between SCA and trigeminal nerve root. A retrosigmoid approach was implemented, and stimulation of the compression point was consistent with the preoperative referred pain.5 Considering the thick superior petrosal vein (SPV), we transposed the offending artery and anchored it over a SPV tributary.6 In this way no prosthetic material was placed in contact with trigeminal nerve, minimizing chance of recurrence.7-9 No abnormality on neurophysiological monitoring was reported, and postoperative imaging demonstrated no edema or hemorrhage, as well successful displacement of SCA. Patient presented complete resolution of pain and no new neurological deficit after 1 year of follow-up. This case is an uncommon report depicting a helpful intraoperative decision to be considered in selected cases to avoid venous sacrifice and preclude prosthetic material in contact with the nerve. Anatomical pictures courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Educational Foundation (NREF).

Combined Application of Arachnoid Membrane and Petrosal Dura to Transpose Dual Offending Arteries in Microvascular Decompression for Trigeminal Neuralgia: Two-Dimensional Operative Video.

Trigeminal neuralgia is featured by episodic and severe unilateral facial pain triggered usually by innocuous cutaneous stimuli.1-4 Microvascular decompression (MVD) is a safe and effective treatment for cases refractory to medical treatment caused by neurovascular conflicts.1,5-7 This Video 1 demonstrates MVD using arachnoid membrane and petrosal dura to transpose dual offending arteries. Informed consent was obtained from the patient for publication of this operative video. The patient was a 64-year-old woman with refractory right trigeminal neuralgia (V2 territory). Preoperative magnetic resonance imaging demonstrated simultaneous conflict between the right trigeminal nerve (TN) and superior cerebellar (SCA) and anterior inferior cerebellar arteries (AICA). Due to progressive and refractory symptoms, MVD was indicated, with aid of neurophysiologic monitoring. A right retrosigmoid approach was employed and after exposure of the TN root, both AICA and SCA were identified conflicting with the nerve. The AICA was displaced inferolaterally and attached to the petrosal dura between the VII/VIII and IX cranial nerves using a USP #0 silk thread. The SCA was mobilized into a fissure created in the lateral pontomesencephalic arachnoid membrane and fixed with shredded Teflon (polytetrafluoroethylene). Another piece of Teflon was positioned between the TN and the proximal segment of AICA to lighten the pulling force from the thread. Postoperative imaging demonstrated no signs of cerebellar contusion or hemorrhage. The patient presented complete resolution of her pain, and no neurologic deficits were observed. We demonstrate MVD with 2 different transposition techniques that can be considered for trigeminal neuralgia with dual offending arteries (AICA, SCA).

Microsurgical Resection of a Middle Cerebellar Peduncle Cavernous Malformation: 3-Dimensional Operative Video.

Brainstem cavernous malformations are frequently surrounded by vital structures, which often makes surgical treatment a challenging task even to the most skilled surgeon. Accordingly, microsurgical excision is preferably offered to symptomatic patients and superficial lesions.1-3 We present the case of a 41-yr-old male presenting with progressive dizziness and diplopia. Neurological examination showed horizontal nystagmus, dysmetria, and unbalance. Preoperative magnetic resonance imaging (MRI) suggested a cavernous malformation in the right middle cerebellar peduncle. A telovelar approach was employed with the guidance of intraoperative neurophysiological monitoring. An exophytic lesion was identified in the right middle cerebellar peduncle and a clear cleavage plane was obtained allowing circumferential dissection around the capsule. The lesion was removed en bloc. Postoperative MRI confirmed a complete excision of the malformation. The patient presented an improvement in his initial symptoms, with no new neurological deficit. Cavernous malformations related with the fourth ventricle can be successfully resected through a telovelar approach in select cases, especially when exophytic, where the surgeon might take advantage of the path created by the lesion. Informed consent was obtained from the patient for the procedure and publication of this operative video. Anatomic images were a courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Education Foundation (NREF).

Microsurgical Resection of a Left Cerebral Peduncle Cavernous Malformation: 3-Dimensional Operative Video.

Brainstem cavernous malformations are challenging lesions considering the numerous eloquent structures frequently related. Surgical resection is the preferred treatment if the patient is symptomatic and the lesion can be safely resected. We present the case of a right-handed 38-yr-old female, presenting with progressive impairment of her handwriting. Physical examination showed a right-sided grade 4/5 hemiparesis. Preoperative imaging was suggestive of a left cerebral peduncle cavernous malformation with a recent area of hemorrhage. The most superficial portion of the lesion was on the surface of the brainstem in the supratrigeminal safe entry zone of the pons. A frontotemporal craniotomy was performed, followed by a pretemporal transtentorial approach. Prior to performing brainstem incision, the area was stimulated, and no motor evoked potential was recorded. The hematoma was then evacuated, and the cavernous malformation was dissected and removed. The capsule was also dissected and removed, using neurophysiological monitoring to guide this procedure. The lesion was completely resected, and the patient was discharged on postoperative day 7 with a right-sided hemiparesis grade 3/5, which improved to grade 5/5 after 4 mo. The patient presented an improvement of her symptoms, with no new neurological deficits. Brainstem cavernomas can be safely removed in selected cases, using the adequate safe entry zone and the appropriate surgical approach. The pretemporal route can be used to reach the anterolateral aspect of the upper part of the brainstem, as it combines the advantages of both transsylvian and subtemporal approaches. An informed consent was obtained from the patient for publication of this operative video.

Anterior Transpetrosal Approach and Microsurgical Resection of a Petrous Tentorial Meningioma: 3-Dimensional Operative Video.

Tentorial meningiomas are challenging tumors because of its complex relationship with vital neurovascular structures. We present the case of a 41-yr-old female with a history of right-sided facial numbness associated with pain around the ear. Magnetic resonance imaging demonstrated a lesion in the right tentorium edge closely related with the porus trigeminus, suggestive of a meningioma. Because of worsening of symptoms the patient underwent surgery for tumor removal. A standard temporo-zygomatic craniotomy was performed, followed by an extradural peeling of the middle fossa; the petrous apex was drilled allowing access to the posterior fossa dura. Dural opening was carried connecting the temporal and posterior fossa, and the tentorium was then cut to the incisura. The tumor was identified and completely removed reaching Simpson grade I resection. Postoperatively, the patient presented a right dry eye in the first days that fully improved, and also a right-sided facial paralysis (House-Brackmann grade IV) and diplopia, both recovered completely after 4 mo. We believe that facial paralysis was the result of an undesired traction of the geniculate ganglion, or upon the nerve itself. To avoid such complication, dissection over the GSPN must be carried parallel to that nerve. Facial numbness and pain improved with no neurological other deficits. Tentorial meningiomas are complex deep-seated lesions that can be successfully approached through an anterior transpetrosal route in selected cases. Informed consent was obtained from the patient for publication of this operative video. Anatomical images were a courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.

Microsurgical Resection of Multiple Giant Glomus Tumors.

Glomus tumors, also called paragangliomas, are challenging lesions, demanding accurate knowledge of complex anatomy and pertinent approaches. We present the case of a 39-year-old male presenting with headache, vertigo, tinnitus, hearing loss, and hoarseness. Neurological assessment showed facial paralysis House-Brackmann IV and lower cranial nerves deficits. Preoperative magnetic resonance imaging (MRI) demonstrated two large lesions, suggestive of a glomus jugulare, and carotid body paragangliomas. Considering worsening of the symptoms and the important mass effect of both lesions over the neurovascular structures, microsurgical excision was offered, after preoperative tumor embolization. We preferred to approach both lesions in the same operation, starting by the cervical tumor. Initially there was not an easily identifiable dissection plane between the tumor and the carotid artery, but it was achieved after performing a subadventitial dissection, being possible to resect the entire lesion. The jugular foramen lesion was approached through a postauricular transtemporal approach, skeletonizing the sigmoid sinus, jugular bulb, and facial nerve, following a complete mastoidectomy. The tumor, extending to the intradural compartment, middle ear, internal auditory canal, petrous internal carotid artery, and internal jugular vein was completely removed. Postoperative MRI demonstrated complete resection of both lesions, and pathology confirmed to be paragangliomas. In the immediate postoperative period, the facial paralysis evolved to House-Brackmann grade VI, improving to grade III during follow-up. The patient underwent a vocal cord medialization in order to improve voice quality and swallowing. These are challenging lesions and extensive laboratory training is mandatory to be familiarized with the regional anatomy and its various surgical approaches. The link to the video can be found at: https://youtu.be/gA_ckwFq_9c .

Microsurgical resection of foramen magnum meningioma through a transcondylar approach: three-dimensional operative video.

Foramen magnum (FM) meningiomas are challenging lesions. We present the case of a 38-year-old female with neck pain, dysphonia, and slight twelfth nerve palsy. Imaging workup was highly suggestive of an FM meningioma, and microsurgical resection with the aid of intraoperative neurophysiological monitoring was indicated. A transcondylar approach was employed, the vertebral artery was mobilized, and the tumor was completely removed. Postoperative MRI demonstrated complete resection. There were no signs of cervical instability. The patient presented with improvement of her symptoms and no new neurological deficit on follow-up. FM meningiomas can be successfully resected using a transcondylar approach, since it increases the exposure of the ventral FM, allowing the surgeon to work parallel to the skull base and flush with the tumor's attachment. Informed consent was obtained from the patient for publication of this operative video. The video can be found here: https://youtu.be/itfUOB-6zM0.

Microsurgical resection of an inferior cerebellar peduncle cavernous malformation: 3-Dimensional operative video.

Brainstem cavernous malformations are especially difficult to treat because of their deep location and intimate relation with eloquent structures. This is the case of a 26-year-old female presenting with dizziness, dysmetria, nystagmus and unbalance. Imaging depicted a lesion highly suggestive of a cavernous malformation in the left inferior cerebellar peduncle. Following a suboccipital midline craniotomy, the cerebellomedullary fissure was dissected and the lesion was identified bulging the surface. The malformation was completely removed with constant intraoperative neurophysiological monitoring. The patient presented improvement of initial symptoms with no new deficits. Surgical resection of brainstem cavernous malformations can be successfully performed, especially when superficial, using the inferior cerebellar peduncle as an entry zone. The video can be found here: https://youtu.be/-GGZe_CaZnQ.

Microsurgical Resection of a Solitary Spinal Epidural Cavernous Angioma: 3-Dimensional Operative Video.

Solitary spinal epidural cavernous angiomas are rare vascular malformations. Surgical excision is the treatment of choice, as these lesions tend to grow or bleed at some point. In this 3-dimensional, narrated video, we present the case of a 61-year-old male who presented with progressive pain in the right paravertebral region secondary to an epidural cavernous angioma located at the T6/T7 level. Under intraoperative neurophysiological monitoring, a laminectomy between T5 and T7 was performed. A reddish, well delimited, and highly vascularized epidural mass was identified and dissected from the adjacent dura and nerve root, and an en bloc total resection was achieved. The patient was discharged neurologically intact on postoperative day 4, presenting a remarkable improvement of his pain at 2-month follow-up. Total excision of these lesions is possible in most of cases, remaining the standard treatment, with minimum complications. All procedures were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All data related to patient identification were removed from this surgical video and manuscript, with no need of a written informed consent.