The authors have no acknowledgments.

NOTE: Prior to performing this procedure, obtain all required institutional approval and patient consent.
1. Surgical Technique
<ol>
	<li>Induce patient with general anesthesia.</li>
	<li>Place radial arterial line for blood pressure monitoring.</li>
	<li>Place patient in the supine position on the operating room table.</li>
	<li>After the head is clamped into the Mayfield Head holder using standard techniques for a pterional craniotomy, position the head 30&#176;-45&#176; with the ipsilateral side up towards the ceiling, except for anterior-communicating artery aneurysms in which the head is placed at 60&#186; to allow for better visualization across the interhemispheric fissure.</li>
	<li>Position the neck midline and translate anteriorly to maximize jugular venous drainage to prevent cerebral edema and then extend the head to position the ipsilateral zygoma at the highest point&#8212;this allows for frontal lobe relaxation and elevation from the orbital roof during dissection without the use of retractors.</li>
	<li>Clip the hair in preparation for standard pterional scalp incision; use about a one to two inch strip behind the hairline.</li>
	<li>Sterilely prep the skin and drape the surgical area according to standard of care.</li>
	<li>Perform a standard curved scalp incision for a pterional approach extending from the midline of the scalp behind the hairline with a gentle curve posteriorly and inferiorly towards the tragus ending it about 3 mm anterior to the tragus and at the level of the superior edge of the zygoma. Perform this incision down to the skull above the superior temporal line and to the muscle fascia at the level of the temporalis muscle.</li>
	<li>Use electrocautery for scalp hemostasis with the bipolar device.</li>
	<li>Cut the temporalis muscle down to the skull using the bovie monopolar electrocautery device.</li>
	<li>Raise a myocutaneous flap keeping the temporalis muscle attached to the undersurface of the scalp for now. Fish-hooks are used to evert the flap after the temporalis muscle is elevated from the skull using a combination of monopolar electrocautery and a periosteal elevator.</li>
	<li>Perform an inverse subfascial dissection in the avascular plane from the undersurface of the myocutaneous flap using Metzenbaum scissors, keeping the fascia and subfacsial fat pad with the scalp to avoid injury to the facial nerve.</li>
	<li>Secure the temporalis muscle posteriorly and inferiorly to expose the pterional region with &#8220;star&#8221; fishhooks.</li>
	<li>Keep all components of the myocutaneous flap moist with wetted gauze.</li>
	<li>Drill a single temporal 5 mm burr-hole at the posterior-most aspect of the planned craniotomy with a 2 mm cutting burr so that the foot plate of the side-cutting drill can be inserted into this hole and then use a side-cutting drill with a foot plate to remove the thumb-sized (approximately 3 x 4 cm) kidney-shaped craniotomy centered anteriorly around the pterion.</li>
	<li>Using a No. 1 Penfield, separate the dura on all sides of the pterion and have an assistant gently retract the dura away from the bone surface that is being drilled to minimize risk of penetrating the dura and causing cortical injury.</li>
	<li>Remove the pterion with a drill: anteriorly, until the superior and lateral aspects of the orbital roof are smooth and flattened down to the outer cortical table of bone, without entering the orbit, to maximize subfrontal exposure; medially, drill until the superior orbital fissure dura is exposed and remove any small pieces of bone that would interfere with medial exposure using either a drill bit or hand-held Lempert bone cutting device. Ensure that excellent hemostasis of all soft-tissue and bone surfaces has been obtained to avoid blood dripping into the intradural space during brain dissection and aneurysm exposure, using electrocaurtery and bone wax as needed, before opening the dura.</li>
	<li>Gently elevate the dura and use a No. 11 scalpel to penetrate the dura and then use dural scissors to create a &#8220;C-shaped&#8221; opening in the dura with the base at the pterion. Secure the dura flat against the outer cortical bone of the orbit without having redundant dural leaflets that would otherwise obscure visualization of the proximal Sylvian Fissure and subfrontal region. This can be performed by using 4-0 Surgilons sutures to tack the dura to the scalp.</li>
</ol>
2. Brain Relaxation
<ol>
	<li>Give 25-50 g of Mannitol at the time of bone flap removal to relax the brain if anesthesia agrees that the blood pressure will tolerate diuresis. 
	NOTE: This will allow time for the diuresis to occur and ultimately will relax the brain to help maximize gravity dependent brain retraction during dissection.</li>
	<li>Keep End-Tidal pCO2 between 30-35 mm Hg to achieve slight hypercapnea. NOTE: This will safely allow for brain relaxation and maximize gravity dependent brain retraction during dissection.</li>
	<li>Evacuate cerebrospinal fluid (CSF) to promote brain relaxation by opening the arachnoid cisterns in the interoptic, carotid-optic, and carotid-oculomotor cisterns and patiently suction CSF until the desired brain relaxation has been achieved. 
	NOTE: This typically takes about 1 min; no lumbar drain is needed with this technique and it dramatically opens the surgical corridors.</li>
</ol>
3. Sylvian Fissure Dissection
<ol>
	<li>Bring the intra-operative microscope with the mouthpiece into the field using sterile techniques. Also bring surgical chairs with arm support into the field sterilely to maximize bimanual dexterity and to prevent surgeon arm and hand fatigue. 
	NOTE: The mouthpiece should be adjusted before draping so that the surgeon can move the microscope with the mouth while simultaneously looking through the ocular pieces.</li>
	<li>Perform dissection. 
	NOTE: For anterior communicating artery aneurysms, no Sylvian Fissure dissection is required and minimal (2-3 mm in extreme cases only, but this is a rare occurrence) to no gyrus rectus resection is needed using only subfrontal dissection; all other supraclinoid anterior circulation aneurysm locations (including posterior communicating artery) require &#60;1 cm proximal Sylivan Fissure dissection to expose the supraclinoid internal carotid artery, its branches (posterior communicating and anterior choroidal arteries), the internal carotid artery terminus, the A1 and M1 origins, and the proximal A2 and M2 segments distal to their respective bifurcations. Total Sylvian Fissure exposure was dime-size (1 cm x 1 cm) and no brain retractors were used for any of the cases reported. Gravity dependent brain relaxation was sufficient for excellent exposure of the soft tissue structures and vasculature needed to perform surgical clip ligation in the areas discussed above.</li>
	<li>Using bimanual manipulation with surgical microinstruments gently open the arachnoid corridors, holding the brain tissue aside with the edge of the instrument handles or suction device as needed through this exposure. 
	NOTE: The senior author&#39;s preference is to use a 4-French Fukishima suction tip in the non-dominant hand and in the dominant hand bipolar bayonettes for blunt dissection or microscissors for sharp dissection. Moistened Telfa strips are placed on the brain surface at the site of manipulation to prevent cortical injury. Cottonoids often stick to the brain surface and can&#8217;t be easily advanced deeper as the dissection progresses, without causing mild cortical injury.</li>
	<li>Use the mouthpiece on the operating microscope frequently to adjust the scope and focus length as needed while keeping both hands in the field.</li>
	<li>Secure the aneurysm in standard fashion, using the suction most often in the non-dominant hand to maintain the surgical corridor and visualization free of CSF.</li>
	<li>After clip placement, perform intra-operative Doppler of the aneurysm dome to confirm cessation of flow as well as the inflow and outflow vessels to confirm flow and carefully examine the aneurysm neck and parent vessels. We reserve intra-operative digital subtraction angiography (DSA) for anterior communicating artery aneurysms and those clipped aneurysms where inflow, outflow, or aneurysm neck cannot be visualized completely or there is a concern with intra-operative Doppler. Intra-operative DSA is preferred over indocyanine green (ICG) angiography because when multiple aneurysm clips are used to reconstruct the aneurysm neck, the clip can obstruct visualization. NOTE: Once the aneurysm has been securely clipped, the microscope is removed from the field and the brain irrigated with normal saline solution to minimize the amount of pneumocephalus after closure.</li>
	<li>After inspecting the clip for aneurysm occlusion with the Doppler, the aneurysm dome is perforated with a 22 G needle attached to intravenous tubing and a 10 ml syringe and manually suction aspirated to confirm aneurysm occlusion.</li>
	<li>Reapproximate the native dura with 4-0 surgilon and cover with a synthetic dural substitute if a watertight closure is not able to be obtained properly.</li>
	<li>Secure bone plates with a metal plating system per standard of care.</li>
	<li>Secure the frontal edge of the bone flap flush against the native bone to avoid space between the two which would not be cosmetically pleasing after the tissues heal.</li>
	<li>Reapproximate the temporalis muscle fascia with interrupted 2-0 Vicryl sutures. Secure the top of the temporalis muscle with a 2-0 Vicryl stitch to the frontal metal plate to reapproximate it to the superior temporal line.</li>
	<li>Reapproximate the galea using 3-0 Vicryl sutures and close the scalp in a standard fashion using either staples, nylon, or prolene. Dress with sterile bandages per surgeon preference.</li>
</ol>
4. Post-treatment Care
<ol>
	<li>Admit patient to the intensive care unit after treatment and mobilize with the nursing staff as soon as sedation or general anesthesia has worn off enough to do so, typically within 6 hr of extubation.</li>
	<li>Order physical and occupational therapy to begin post-operative day one in order to assess the patient for safe discharge to home if there were any concerns by the nursing staff.</li>
	<li>Discharge the patient when criteria are met: pain controlled with only oral medications, voiding independently, ambulating independently, and tolerating oral food intake.</li>
</ol>

<ol>
	<li>Guglielmi, G., Vi&#241;uela, F., Dion, J., Duckwiler, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrothrombosis+of+saccular+aneurysms+via+endovascular+approach.+Part+2:+Preliminary+clinical+experience.">Electrothrombosis of saccular aneurysms via endovascular approach. Part 2: Preliminary clinical experience.</a> Journal of neurosurgery. 75 (1), 8-14 (1991).</li><li>Hoh, B. L., Chi, Y. -. Y., Dermott, M. A., Lipori, P. J., Lewis, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+coiling+versus+clipping+of+ruptured+and+unruptured+cerebral+aneurysms+on+length+of+stay,+hospital+cost,+hospital+reimbursement,+and+surgeon+reimbursement+at+the+university+of+Florida.">The effect of coiling versus clipping of ruptured and unruptured cerebral aneurysms on length of stay, hospital cost, hospital reimbursement, and surgeon reimbursement at the university of Florida.</a> Neurosurgery. 64 (4), 614-619 (2009).</li><li>Wiebers, D. O., Whisnant, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unruptured+intracranial+aneurysms:+natural+history,+clinical+outcome,+and+risks+of+surgical+and+endovascular+treatment.">Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment.</a> Lancet. 362 (9378), 103-110 (2003).</li><li>Molyneux, A., Kerr, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=International+Subarachnoid+Aneurysm+Trial+(ISAT)+of+neurosurgical+clipping+versus+endovascular+coiling+in+2143+patients+with+ruptured+intracranial+aneurysms:+a+randomised+trial.">International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial.</a> Lancet. 360 (9342), 1267-1274 (2002).</li><li>Spetzler, R. F., McDougall, C. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Barrow+Ruptured+Aneurysm+Trial:+3-year+results.">The Barrow Ruptured Aneurysm Trial: 3-year results.</a> Journal of neurosurgery. , (2013).</li><li>Spetzler, R. F., Sanai, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+quiet+revolution:+retractorless+surgery+for+complex+vascular+and+skull+base+lesions.">The quiet revolution: retractorless surgery for complex vascular and skull base lesions.</a> Journal of neurosurgery. 116 (2), 291–-300 (2012).</li><li>Chalouhi, N., Jabbour, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+treatment+of+ruptured+anterior+circulation+aneurysms:+comparison+of+pterional+and+supraorbital+keyhole+approaches.">Surgical treatment of ruptured anterior circulation aneurysms: comparison of pterional and supraorbital keyhole approaches.</a> Neurosurgery. 72 (3), 437-441 (2013).</li><li>Petraglia, A. L., Srinivasan, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+subfrontal+approach+to+anterior+communicating+artery+aneurysms:+A+review+of+28+patients.">Unilateral subfrontal approach to anterior communicating artery aneurysms: A review of 28 patients.</a> Surgical neurology international. 2, 124 (2011).</li><li>Goettel, N., Chui, J., Venkatraghavan, L., Tymianski, M., Manninen, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Day+Surgery+Craniotomy+for+Unruptured+Cerebral+Aneurysms:+A+Single+Center+Experience.">Day Surgery Craniotomy for Unruptured Cerebral Aneurysms: A Single Center Experience.</a> Journal of neurosurgical anesthesiology. , (2013).</li><li>Andaluz, N., Zuccarello, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+trends+in+the+treatment+of+cerebral+aneurysms:+analysis+of+a+nationwide+inpatient+database.">Recent trends in the treatment of cerebral aneurysms: analysis of a nationwide inpatient database.</a> Journal of neurosurgery. 108 (6), 1163-1169 (2008).</li><li>Barker, F. G., Amin-Hanjani, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-dependent+differences+in+short-term+outcome+after+surgical+or+endovascular+treatment+of+unruptured+intracranial+aneurysms+in+the+United+States.">Age-dependent differences in short-term outcome after surgical or endovascular treatment of unruptured intracranial aneurysms in the United States.</a> Neurosurgery. 54 (1), 18-28 (1996).</li><li>Cowan, J. A., Ziewacz, J., Dimick, J. B., Upchurch, G. R., Thompson, B. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+endovascular+coil+embolization+and+surgical+clip+occlusion+for+cerebral+artery+aneurysms.">Use of endovascular coil embolization and surgical clip occlusion for cerebral artery aneurysms.</a> Journal of neurosurgery. 107 (3), 530-535 (2007).</li><li>Crowley, R. W., Yeoh, H. K., Stukenborg, G. J., Ionescu, A. A., Kassell, N. F., Dumont, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+weekend+versus+weekday+hospital+admission+on+mortality+following+subarachnoid+hemorrhage.+Clinical+article.">Influence of weekend versus weekday hospital admission on mortality following subarachnoid hemorrhage. Clinical article.</a> Journal of neurosurgery. 111 (1), 60-66 (2009).</li><li>Hoh, B. L., Chi, Y. -. Y., Lawson, M. F., Mocco, J., Barker, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Length+of+stay+and+total+hospital+charges+of+clipping+versus+coiling+for+ruptured+and+unruptured+adult+cerebral+aneurysms+in+the+Nationwide+Inpatient+Sample+database+2002+to+2006.">Length of stay and total hospital charges of clipping versus coiling for ruptured and unruptured adult cerebral aneurysms in the Nationwide Inpatient Sample database 2002 to 2006.</a> Stroke; a journal of cerebral circulation. 41 (2), 337-342 (2010).</li><li>Hoh, B. L., Rabinov, J. D., Pryor, J. C., Carter, B. S., Barker, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-hospital+morbidity+and+mortality+after+endovascular+treatment+of+unruptured+intracranial+aneurysms+in+the+United+States,+1996-2000:+effect+of+hospital+and+physician+volume.">In-hospital morbidity and mortality after endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000: effect of hospital and physician volume.</a> AJNR. American journal of neuroradiology. 24 (7), 1409-1420 (2003).</li><li>Shea, A. M., Reed, S. D., Curtis, L. H., Alexander, M. J., Villani, J. J., Schulman, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+of+nontraumatic+subarachnoid+hemorrhage+in+the+United+States+in+2003.">Characteristics of nontraumatic subarachnoid hemorrhage in the United States in 2003.</a> Neurosurgery. 61 (6), 1131-1137 (2007).</li><li>Rodr&#237;guez-Hern&#225;ndez, A., Sughrue, M. E., Akhavan, S., Habdank-Kolaczkowski, J., Lawton, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+management+of+middle+cerebral+artery+aneurysms:+surgical+results+with+a+&#8220;clip+first&#8221;+policy.">Current management of middle cerebral artery aneurysms: surgical results with a &#8220;clip first&#8221; policy.</a> Neurosurgery. 72 (3), 415-427 (2013).</li><li>Van Lindert, E., Perneczky, A., Fries, G., Pierangeli, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+supraorbital+keyhole+approach+to+supratentorial+aneurysms:+concept+and+technique.">The supraorbital keyhole approach to supratentorial aneurysms: concept and technique.</a> Surgical neurology. 49 (5), 489-490 (1998).</li><li>Dott, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracranial+aneurysms:+cerebral+arteriography:surgical+treatment.">Intracranial aneurysms: cerebral arteriography:surgical treatment.</a> Edinb Med J. 40, 219-234 (1933).</li><li>Dandy, W. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aneurysm+of+the+anterior+cerebral+artery.">Aneurysm of the anterior cerebral artery.</a> Journal of the American Medical Association. 119 (16), 1253-1254 (1942).</li><li>Yasargil, M., Fox, J., Ray, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+operative+approach+to+aneurysms+of+the+anterior+communicating+artery.">The operative approach to aneurysms of the anterior communicating artery.</a> Advances and Technical Standards in Neurosurgery. 2, 113-170 (1975).</li><li>Al-Mefty, O., Fox, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Superolateral+orbital+exposure+and+reconstruction.">Superolateral orbital exposure and reconstruction.</a> Surgical neurology. 23 (6), 609-613 (1985).</li><li>Heros, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+supraorbital+&#8220;keyhole&#8221;+approach.">The supraorbital &#8220;keyhole&#8221; approach.</a> Journal of neurosurgery. 114 (3), 850-851 (2011).</li></ol>

Eric Deshaies is a physician consultant for MicroVention, Covidien Neurovascular, Integra LifeSciences Corporation.

Surgical clip ligation of intracranial aneurysms remains a relevant and important option in treating certain types of aneurysms, though this role has been diminishing over the past several years as endovascular technology becomes safer and more efficacious. Endovascular treatment has surpassed surgery for cerebral aneurysms, yet the higher recurrence rate after endovascular treatment, the occasional need for surgical treatment after aneurysm recurrence from failed endovascular treatment, specific morphologies making endo...

Surgical clip ligation had been the mainstay of treatment for intracranial aneurysms but has been recently supplanted mostly by less invasive endovascular techniques.1,2 Clinical trials including the International Study of Unruptured Intracranial Aneurysms (ISUIA-1 and ISUIA-2), and the International Subarachnoid Aneurysm Trial (ISAT) have demonstrated lower morbidity and mortality, reduced length of hospital stay, and lower overall expense, with endovascular treatment compared to surgical clip ligation.3&#8211;5 However, the higher aneurysm recurrence rate after endovascular therapy has led to the examination of the cumulative risk to the patients compared to surgical clip ligation.3,4 Surgical treatment remains an important modality for aneurysm therapy, particularly for anterior circulation aneurysms that have morphologies that may be difficult to treat with endovascular means.
Unlike advancements in endovascular devices, few advances in surgical techniques have been made recently. Techniques to make surgical treatment less invasive have included the supraorbital craniotomy combined with the eyebrow incision for anterior circulation aneurysms and &#8220;retractorless surgery&#8221; to minimize surgical trauma to the brain during aneurysm clipping.6&#8211;8 These less invasive surgical approaches may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes.9
Here, we present our experience with a minimally invasive approach to surgical clip ligation of unruptured intracranial aneurysms using a pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an age matched dataset from the Nationwide Inpatient Sample (NIS). The surgical technique will be reviewed, including patient preparation, brain relaxation, sylvian fissure dissection, and closure. Post-operative care and discharge requirements will also be outlined.

<table border="0" cellpadding="0" cellspacing="0" width="963">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Mayfield Infinity skull clamp</td>
			<td style="width:125px;">Integra</td>
			<td style="width:368px;">A-1114</td>
			<td style="width:64px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Mayfield table attachment</td>
			<td style="width:125px;">Integra</td>
			<td style="width:368px;">A-1018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">4-French Fukishima suction tip</td>
			<td style="width:125px;">Integra</td>
			<td style="width:368px;">R-8986</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Periosteal elevator (Langenbeck)</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">65-1116</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Metzenbaum scissors</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">36-5023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Malis dissector, round angled</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">80-1541&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Penfield dissector, style 1</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">65-1015</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Lempert bone rongeur</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">19-1232</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Malis Irrigation Module</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;">Module 1000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Bovie monopolar electrocautery device</td>
			<td style="width:125px;">Codman</td>
			<td style="width:368px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Insulated blade for electrocautery device</td>
			<td style="width:125px;">Covidien</td>
			<td style="width:368px;">E1455</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Fish-hook retractors</td>
			<td style="width:125px;">Lone Star</td>
			<td style="width:368px;">3350-8G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Pneumatic drill</td>
			<td style="width:125px;">Medtronic</td>
			<td style="width:368px;">Midas Rex MR7</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Side-cutting drill</td>
			<td style="width:125px;">Medtronic</td>
			<td style="width:368px;">F2/8TA23</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Fluted legend match head tool</td>
			<td style="width:125px;">Medtronic</td>
			<td style="width:368px;">10MH30</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Surgical scalpel No. 10,11,15</td>
			<td style="width:125px;">Bard-Parker</td>
			<td style="width:368px;">0029064 (No.10), 0018291 (No.11), 0018043 (No.15)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Intra-operative microscope with mouthpiece</td>
			<td style="width:125px;">Leica</td>
			<td style="width:368px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Microscissors</td>
			<td style="width:125px;">V. Mueller</td>
			<td style="width:368px;">NL3785-034(st), NL3785-035(cvd)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Rhoton dissector, #2</td>
			<td style="width:125px;">V. Mueller</td>
			<td style="width:368px;">NL3785-002&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Telfa strips</td>
			<td style="width:125px;">American Surgical</td>
			<td style="width:368px;">#80-09 (1/2x3), #80-04 (1/4x3)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Aneurysm clip</td>
			<td style="width:125px;">Aesculap</td>
			<td style="width:368px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Raney clip applier</td>
			<td style="width:125px;">Aesculap</td>
			<td style="width:368px;">FF012R</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Synthes Matrix metal plating system</td>
			<td style="width:125px;">Synthes</td>
			<td style="width:368px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Braided absorbable surgical sutures (Vicyrl)&#160;</td>
			<td style="width:125px;">Ethicon</td>
			<td style="width:368px;">J790D (3-0), J743D (4-0)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Braided nylon nonabsorbable surgical sutures (Nurolon) 4-0</td>
			<td style="width:125px;">Ethicon</td>
			<td style="width:368px;">C584D</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:407px;">Doppler System</td>
			<td style="width:125px;">Mizuho</td>
			<td style="width:368px;">07-150-02</td>
			<td></td>
		</tr>
	</tbody>
</table>

minimally invasive thumb-sized pterional craniotomy for surgical clip ligation of unruptured anterior circulation aneurysms

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients &#8804;55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged &#8804;55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Currently, at our institution over 150 aneurysms are treated annually. From August 2008 to December 2012, 22 elective aneurysm clippings using this minimally invasive thumb-sized pterional craniotomy technique for supraclinoidal aneurysms on patient&#8217;s &#8804;55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon that developed this technique (EMD) (Table 1). This age group was chosen as earlier trials have shown that surgical treatment of aneury...

Watch this Scientific Journal Video about Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms at JoVE.com

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve ...

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Research

JoVE Journal

Medicine

15.4K Views.  Crouse Neuroscience Institute. Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Video: Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Minimally Invasive Establishment of Murine Orthotopic Bladder Xenografts

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable cell lines are inoculated either by intravesical instillation (model of nonmuscle invasive growth) or intramural injection into the bladder wall (model of invasive growth). Both procedures are complex and highly time-consuming. Additionally, the superficial model has its shortcomings due to the lack of cell lines that are tumorigenic following instillation. Intramural injection, on the other hand, is marred by the invasiveness of the procedure and the associated morbidity for the host mouse.
With these shortcomings in mind, we modified previous methods to develop a minimally invasive approach for creating orthotopic bladder cancer xenografts. Using ultrasound guidance we have successfully performed percutaneous inoculation of the bladder cancer cell lines UM-UC1, UM-UC3 and UM-UC13 into 50 athymic nude. We have been able to demonstrate that this approach is time efficient, precise and safe. With this technique, initially a space is created under the bladder mucosa with PBS, and tumor cells are then injected into this space in a second step. Tumor growth is monitored at regular intervals with bioluminescence imaging and ultrasound. The average tumor volumes increased steadily in in all but one of our 50 mice over the study period.
In our institution, this novel approach, which allows bladder cancer xenograft inoculation in a minimally-invasive, rapid and highly precise way, has replaced the traditional model.

The established technique to inoculate primary invasive orthotopic bladder cancer xenografts requires laparotomy and mobilization of the bladder. This procedure inflicts significant morbidity on the mice, is technically challenging and time-consuming. We therefore developed a high-precision, percutaneous approach utilizing ultrasound guidance.

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable ...

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Encapsulation Thermogenic Preadipocytes for Transplantation into Adipose Tissue Depots

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular weight metabolites in tissues of the treated host to achieve long-term survival. The semipermeable membrane allows engrafted encapsulated cells to avoid rejection by the immune system. The encapsulation procedure was designed to enable a controlled release of bioactive compounds, such as insulin, other hormones, and cytokines. Here we describe a method for encapsulation of catabolic cells, which consume lipids for heat production and energy dissipation (thermogenesis) in the intra-abdominal adipose tissue of obese mice. Encapsulation of thermogenic catabolic cells may be potentially applicable to the prevention and treatment of obesity and type 2 diabetes. Another potential application of catabolic cells may include detoxification from alcohols or other toxic metabolites and environmental pollutants.

Here, we present a protocol for encapsulation of catabolic cells, which consume lipids for heat production in intra-abdominal adipose tissue and increase energy dissipation in obese mice.

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

An Anatomical Study of Nerves at Risk During Minimally Invasive Hallux Valgus Surgery

The growing popularity of minimally invasive surgical (MIS) procedures makes it necessary that new anatomical references arise, to aid in tridimensional orientation and localization of structures that are not directly visible to the surgeon. This is especially critical for structures at risk like nerves or blood vessels. Optimization of the handling of cadaveric material and the combination of multiple techniques compensate for the limited availability of adequate specimens. The described protocol combines anatomical plane-by-plane dissection and sectional anatomy of fresh-frozen specimens to help localize relevant structures, such as nerves, arteries, veins and to correctly position the portals during MIS procedures. Depiction of these structures in anatomy textbooks can differ from what is encountered in the surgical field; and for this reason, new anatomical studies with a surgical orientation are needed. However, this is a complex, time-consuming technique requiring specific training. The anatomical references described with the so-called 'clock method' provide the surgeon with an easy and reproducible system to locate the path of the nerves at risk in Hallux Valgus MIS procedures. This model can be extrapolated to many other minimally invasive surgical procedures.

Minimally invasive surgical (MIS) procedures rely on anatomical references to localize structures not directly visible to the surgeon. This manuscript describes a combined method of plane-by-plane dissection and sectional anatomy of fresh-frozen specimens to locate the structures at risk during MIS procedures.

The growing popularity of minimally invasive surgical (MIS) procedures makes it necessary that new anatomical references arise, to aid in tridimensional ...

Endoscopic Septoplasty with Limited Two-line Resection: Minimally Invasive Surgery for Septal Deviation

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal deviation. It has a long history with multiple variations. In this article, a modified endoscopic septoplasty procedure using the limited two-line resection (2LoRs) technique at the posterior and inferior junction of the cartilaginous and bony septum is presented based on embryologic and anatomic knowledge of the nasal septum and the biomechanics of cartilaginous behavior. With this procedure, the quadrangular cartilage can be preserved as much as possible, which is helpful in retaining the supporting framework and rigidness of the septum. 2LoRs has been proven effective and sound for the correction of nasal septal deviation with rare complications. This modified procedure can be applied to correct the deviated nasal septum in the absence of any external nasal deformity to improve nasal patency or to improve access to the middle meatus or to the axillary region of the middle turbinate. It may also be used to expand the indications of septoplasty to children and adolescents because of its minimally invasive approach.

Endoscopic septoplasty is a time-honored surgical procedure with multiple variations. This paper focuses on a step-by-step surgical approach to perform a modified septoplasty procedure known as limited two-line resection. This surgical technique can be applied to correct a deviated nasal septum in the absence of an external nasal deformity.

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal ...

Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or excision. Many of these nodules are identified and excised via minimally invasive thoracic surgery; however, subcentimeter and subsolid nodules are frequently difficult to identify intra-operatively. This can be mitigated by the use of electromagnetic transthoracic needle localization. This protocol delineates the step-by-step process of electromagnetic localization from the pre-operative period to the postoperative period and is an adaptation of the electromagnetically guided percutaneous biopsy previously described by Arias et al. Pre-operative steps include obtaining a same day CT followed by the generation of a three-dimensional virtual map of the lung. From this map, the target lesion(s) and an entry site are chosen. In the operating room, the virtual reconstruction of the lung is then calibrated with the patient and the electromagnetic navigation platform. The patient is then sedated, intubated, and placed in the lateral decubitus position. Using a sterile technique and visualization from multiple views, the needle is inserted into the chest wall at the prechosen skin entry site and driven down to the target lesion. Dye is then injected into the lesion and, then, continuously during needle withdrawal, creating a tract for visualization intra-operatively. This method has many potential benefits when compared to the CT-guided localization, including a decreased radiation exposure and decreased time between the dye injection and the surgery. Dye diffusion from the pathway occurs over time, thereby limiting intra-operative nodule identification. By decreasing the time to surgery, there is a decrease in wait time for the patient, and less time for dye diffusion to occur, resulting in an improvement in nodule localization. When compared to electromagnetic bronchoscopy, airway architecture is no longer a limitation as the target nodule is accessed via a transparenchymal approach. Details of this procedure are described in a step-by-step fashion.

Presented here is a protocol for lung nodule localization using dye marking via electromagnetically navigated transthoracic needle access. The technique described here can be accomplished in the peri-operative period to optimize nodule localization and to successful resection when performing minimally invasive thoracic surgery.

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or ...

Absorbent Microbiopsy Sampling and RNA Extraction for Minimally Invasive, Simultaneous Blood and Skin Analysis

Conventional skin biopsy limits the clinical research that involves cosmetically sensitive areas or pediatric applications due to its invasiveness. Here, we describe the protocol for using&#160;an absorbent microneedle-based device, absorbent microbiopsy, for minimally invasive sampling of skin and blood mixture. Our goal is to help facilitate rapid progress in clinical research, the establishment of biomarkers for skin disease and reducing the risk for clinical research participants. In contrast to conventional skin biopsy techniques, the absorbent microbiopsy can be performed within seconds and does not require intensive training due to its simple design. In this report, we describe the use of absorbent microbiopsy, including loading and application, on a&#160;volunteer. Then, we show how to isolate RNA from the absorbed sample. Finally, we demonstrate the use of quantitative reverse transcription PCR (RT-qPCR) to quantify mRNA expression levels of both blood (CD3E and CD19) and skin (KRT14 and TYR). The methods that we describe utilize off the shelf kits and reagents. This protocol offers a minimally invasive approach for simultaneous sampling of skin and blood within the same absorbent microbiopsy matrix. We have found human ethics committees, clinicians and volunteers to be supportive of this approach to dermatological research.

In this article, we demonstrate how the absorbent microbiopsy technique is performed and how the sample can be used for RNA extraction for simple and simultaneous sampling of skin and blood in a minimally invasive manner.

Conventional skin biopsy limits the clinical research that involves cosmetically sensitive areas or pediatric applications due to its invasiveness. Here, ...

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many areas of biomedical research due to its cost-effectiveness and its translation to humans. This protocol describes a method to create a preclinical free skin flap model in rats with ischemia-reperfusion injury. The described 3 cm x 6 cm rat free skin flap model is easily obtained after the placement of several vascular ligatures and the section of the vascular pedicle. Then, 8 h after the ischemic insult and completion of the microsurgical anastomosis, the free skin flap develops the tissue damage. These ischemia-reperfusion injury-related damages can be studied in this model, making it a suitable model for evaluating therapeutic agents to address this pathophysiological process. Furthermore, two main monitoring techniques are described in the protocol for the assessment of this animal model: transit-time ultrasound technology and laser speckle contrast analysis.

Here, we describe a pre-clinical animal model for studying the pathophysiology of ischemia-reperfusion injury in reconstructive microsurgery. This free skin flap model based on the superficial caudal epigastric vessels in the rat may also allow for the evaluation of different therapies and compounds to counteract ischemia-reperfusion injury-related damage.

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many ...

Evaluation of Capnography Sampling Line Compatibility and Accuracy when Used with a Portable Capnography Monitor

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment of end-tidal CO2 (ETCO2), its accuracy is commonly validated using commercial kits composed of a capnography monitor and its matching disposable nasal cannula sampling lines. The purpose of this study was to assess the compatibility and accuracy of cross-paired capnography sampling lines with a single portable bedside capnography monitor. A series of 4 bench tests were performed to evaluate the tensile strength, rise time, ETCO2 accuracy as a function of respiratory rate, and ETCO2 accuracy in the presence of supplemental O2. Each bench test was performed using specialized, validated equipment to allow for a full evaluation of sampling line performance. The 4 bench tests successfully differentiated between sampling lines from different commercial sources and suggested that due to increased rise time and decreased ETCO2 accuracy, not all nasal cannula sampling lines provide reliable clinical data when cross-paired with a commercial capnography monitor. Care should be taken to ensure that any cross-pairing of capnography monitors and disposable sampling lines is fully validated for use across respiratory rates and supplemental O2 flow rates commonly encountered in clinical settings.

The goal of this study was to evaluate the accuracy of capnography sampling lines used in conjunction with a portable bedside capnography monitor. Sampling lines from 7 manufacturers were evaluated for tensile strength, rise time, and ETCO2 accuracy as a function of respiratory rate or supplemental oxygen flow rate.

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment ...