Open Surgical Resection of Cerebral Arteriovenous Malformations

Samenvatting

Source: Rennert, R. C., et al. Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations. J. Vis. Exp. (2017).

This video demonstrates the open surgical resection of a cerebral arteriovenous malformation (AVM) in a human brain. The procedure involves creating a bone flap, accessing the subarachnoid space, identifying and occluding feeding arteries and draining veins, and carefully removing the AVM. Intraoperative angiography confirms complete resection, followed by closure of the surgical site and patient monitoring during recovery.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.

1. AVM resection

1. Obtain informed consent, with assistance from anesthesia, place the patient under general anesthesia, and position the patient based on the location of the AVM and the desired craniotomy. Have blood consent and products available.

2. In conjunction with a neuromonitoring team, establish baseline neuromonitoring, with continued monitoring throughout the case.

3. Sync pre-operative imaging with an intra-operative neuro-navigation system using surface matching, marker, or pointer registration as per the neuronavigation system specifications.

4. Obtain groin access if a sheath is not already in place.

5. Perform a craniotomy tailored to the specific AVM location within the cranium using a high-power drill system, ensuring a wide bony exposure.

1. Incise the skin and galea using a #15 blade. Obtain hemostasis by placement of Raney clips on the skin edges and/or with Bovie electrocautery using the coagulate setting (Bovie Medical Products, Clearwater, FL). If the planned incision involves the underlying muscle, incise the fascia/muscle with electrocautery. Expose the cranium by elevating the incised soft tissue flap from the bone with a periosteal elevator. Alternatively, a pericranial graft can be separately harvested at this time to assist later with closure. Hooks are used for soft tissue retraction. Irrigate and obtain hemostasis.
2. Create one or multiple burr holes on the periphery of the desired craniotomy with a 3 mm diameter matchstick drill bit using a high-power drill system. Additional burr holes will allow for shorter bony cuts and for the dura to be stripped multifocally prior to performing the craniotomy.
3. Strip the dura locally from the inside of the skull by scraping the inner surface of the bone with a bone elevator or footplate attachment and complete the craniotomy by connecting the burr holes with a tapered drill bit with a footplate attachment for dural protection. If possible, plan the craniotomy to ensure early access to cerebrospinal fluid (CSF) cisterns for drainage.
4. Alternatively, place an external ventricular drain into the lateral ventricle at either Frazier's or Kocher's point (after creating a small burr hole and opening the dura sharply using a #11 blade) for CSF drainage. A lumbar drain placed in the lumbar thecal sac following a puncture with a large-bore Tuohy needle at approximately the L3-L4 or L4-L5 interspace may also be used for CSF drainage.

6. After removal of the bone flap and obtaining hemostasis through bipolar electrocautery, place dural tack-up sutures to close off the epidural space by drilling small holes in the bone around the craniotomy with a C1 drill bit and securing the dura to the bone at these sites using 4-0 sutures. Then, open the dura sharply using a #11 or #15 blade. Take great care not to injure the underlying cortex or cortical vessels. Once a small durotomy has been created, open the remaining exposed dura in either a cruciate or C-shaped fashion using Metzenbaum scissors, with Gerald forceps used to elevate the dural edge and visualize the tips of the scissors while cutting to preserve underlying cortical structures.

7. Using an operating microscope with a variable magnification capacity of approximately 1.5x to 17.0x with a 10x eyepiece, excise the AVM. Other forms of surgical magnification, such as an exoscope, can also be used.

1. Start microsurgical resection by first dissecting within the subarachnoid space (using a combination of blunt and sharp techniques with bipolar forceps, a curved dissector, and microscissors) to define the AVM anatomy and expose its margins, free draining veins, and obtain proximal control by identifying and dissecting free all feeding arteries.
2. Take great care to identify and preserve the draining veins early in the AVM dissection, as occlusion of the venous drainage prior to the arterial feeders results in engorgement of the AVM and increased rupture risk.
3. After defining this anatomy, coagulate arterial feeding arteries as they enter the AVM in a proximal to distal fashion using bipolar electrocautery by gently holding the vessel between the tips of the bipolar forceps and using up to 30 watts of power or by the placement of small aneurysm clips.
4. Dissect circumferentially within the brain parenchyma immediately around the AVM nidus using bipolar forceps (for dissection and electrocautery) and a variable action suction tip. A brain retractor may be used to facilitate visualization for deep dissections.
5. After completion of the AVM dissection, coagulate using bipolar electrocautery and/or clip any draining veins. Remove the AVM from the resection cavity. It is critical to remove the entire lesion to eliminate future hemorrhage risk.
6. If surgical resection is attempted post-hemorrhage, perform the removal of the hematoma remote from the AVM nidus until the brain is decompressed and feeding vessels and draining veins are identified. After these landmarks are identified, continue AVM nidal resection.

8. After AVM removal, perform an intra-operative angiogram, using the arterial sheath. Use intraoperative single- or bi-plane angiography or C-arm fluoroscopy to ensure complete nidal resection.

9. Obtain meticulous hemostasis using bipolar electrocautery and by gently lining the resection cavity with absorbable hemostatic agents. Close or re-approximate the dura using 4-0 sutures and, if needed, a peri-cranial or synthetic dural graft. Replace and secure the bone flap using a plating system and close the galea and skin using interrupted absorbable sutures for the deep layers and either staples or running sutures for the skin. Remove the groin sheath and secure the groin.

10. Extubate, if able, and transfer the patient to the ICU for close neurologic monitoring and recovery.

Materialen

Lijst van materialen gebruikt in dit artikel

Naam	Bedrijf	Catalogusnummer	Opmerkingen
Midas Rex High Power Drill System	Medtronic, Minneapolis, MN	PM700	Used for craniotomy
Matchstick Drill Bit	Medtronic, Minneapolis, MN	10MH30-MN	Used to create burr hole for craniotomy
Tapered Drill Bit	Medtronic, Minneapolis, MN	F1/8TA15	Used to complete craniotomy
#11 and 15 Blade Surgical Scalpels	BD Bard-Parker, Franklin Lakes, NJ	372615	Used for groin incision for angiography and dural opening for external ventricular drain placement or AVM resection
Metzenbaum Dissecting Scissors	Stoelting Co, Wood Dale, IL	52134-01P	Used for dural opening
Bone Elevator	Stoelting Co, Wood Dale, IL	52169	Used for separating dura from the inner skull
Gerald Forceps	Stoelting Co, Wood Dale, IL	52106-52	Used for dural opening and manipulation
Microsurgical Instruments	Accurate Surgical & Scientific Instruments Corporation, Westbury, NY	ASSI.BML1	Used for AVM microsurgical resection
Bipolar Forceps	Accurate Surgical & Scientific Instruments Corporation, Westbury, NY	ASSI.BPNS20423FP	Used for AVM microsurgical resection
Electrosurgery Generator	Bovie Medical Products, Clearwater, FL	IDS-200	Used for electrosurgical cutting/coagulation
Small Aneurysm Clips	Codman Neuro, Raynham, MA	20-1801	Used for occlusion of arterial AVM feeders not amenable to coagulation
Brain Retractors	Medicon, Tuttlingen, Germany	22.00.06	For brain retraction for deep AVM dissection/resection
Variable Action Suction tip	Millennium Surgical, Narberth, PA	6-8607	For suction with AVM dissection/resection
Fibrillar Absorbable Hemostatic Agent	Ethicon, Somerville, NJ	63713-0019-61	For hemostatis within surgical cavity
4-0 Suture	Ethicon, Somerville, NJ	C554D	For dural closure
2-0 Absorbable Suture	Ethicon, Somerville, NJ	J286G	For deep tissue closure
3-0 Nylon Suture	Ethicon, Somerville, NJ	ET-663G	For skin closure
Surgical Staples	Medline, Mundelein, IL	STAPLER35RB	For skin closure
Bone Plating System	Biomet, Warsaw, IN	15-7378-12	For bone flap securement
Operating Microscope	Leica Microsystems, Buffalo Grove, IL	M720 OH5	Used for AVM microsurgical resection
BrainLab Neuronavigation Imaging System	Brainlab, Inc, Chicago, IL	Brainlab Curve	Used for AVM microsurgical resection