Exposure Of Carotid Artery Research Articles

Urgent Endovascular Covered-Stent Treatment of Internal Carotid Artery Injury Caused by a Gunshot

Penetrating non-lethal injuries to the distal extra-cranial internal carotid artery are often a surgical challenge, because of the difficulty of direct exposure and repair of the internal carotid artery at the skull base. We describe a case of a successful emergency treatment, with an endovascular procedure using a PTFE covered-stent, of an internal carotid artery haemorrhagic pseudoaneurysm following penetrating trauma to the neck by single gunshot.

The Posterior Pedicle Inferior Turbinate Flap: A New Vascularized Flap for Skull Base Reconstruction

Expanded endonasal approaches (EEA) for the resection of lesions of the anterior and ventral skull base can create large defects with a significant risk of postoperative cerebrospinal fluid (CSF) leaks or exposure of the internal carotid artery. In these cases, a reconstruction using a vascularized flap facilitates rapid and complete healing of the defect. The Hadad-Bassagasteguy flap (HBF), a posterior pedicle nasoseptal flap, is our preferred reconstructive option; however, a prior posterior septectomy or prior wide sphenoidotomies preclude its use. We have developed two additional pedicled flaps to reconstruct these selected patients: the transpterygoid temporoparietal fascia flap, which is suitable for large defects, and the posterior pedicle inferior turbinate flap (PPITF), the subject of this paper. We developed a flap comprising the inferior turbinate mucoperiosteum pedicled on the inferior turbinate artery, a terminal branch of the posterior lateral nasal artery, which arises from the sphenopalatine artery. We retrospectively reviewed the clinical data of four patients who underwent a skull base reconstruction using a PPITF. Four patients underwent a reconstruction with the PPITF after undergoing an EEA that produced a skull base defect associated with a CSF fistula (n = 2), an exposed internal carotid artery (n = 1), or a basilar aneurysm clip (n = 1). All patients had undergone posterior septectomies as part of previous EEAs. All flaps healed uneventfully and covered the entire defect. The PPITF is a viable reconstructive option for patients with skull base defects of a limited size defect and in whom the HBF is not available.

Pharyngocutaneous Fistula Repair After Radiotherapy and Salvage Total Laryngectomy

Managing a pharyngocutaneous fistula in patients who have had total laryngectomy and radiotherapy is difficult. The purpose of this study was to review our experience using anterolateral thigh flaps to repair these defects. Between May 2002 and May 2006, pharyngocutaneous fistulas were repaired in nine consecutive patients. The first five patients had been managed conservatively for several months before repair was performed. The recent four patients were repaired within 1 month of fistula formation. Eight patients had frozen necks, which required neck resurfacing. Risky carotid artery exposure was avoided by using the transverse cervical vessels as recipient vessels. Pharyngocutaneous fistulas occurred between 8 and 30 days after a total laryngectomy. Early repair was much easier than late repair due to severe scaring and stricture associated with long-standing fistulas. All flaps survived. The mean hospitalization was 7 days. No recurrent fistulas or strictures developed after 11 to 48 months of follow-up. All patients achieved 100% oral alimentation. Five of the six patients eligible for tracheoesophageal puncture achieved fluent speech. Using the multi-island anterolateral thigh flap and transverse cervical vessels in pharyngeal reconstruction provides quick recoveries and excellent functional outcomes. Early repair is strongly recommended once a postlaryngectomy pharyngocutaneous fistula is identified.

Mandibular Subluxation for Distal Cervical Exposure of the Internal Carotid Artery

Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible. Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS. After MS, a 5.52 +/- 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure. MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.

Differences in the Anticoagulant Activity of Murine and Human Activated Protein C (APC) in Mouse Thrombosis Models.

APC is a potent mediator of anticoagulant and anti-inflammatory properties. Clinical studies showed that APC reduces mortality in severe sepsis patients. Animal studies are essential for providing a framework to the assessment of mechanism of complex diseases and to test therapeutic agents. Studies of APC function in vivo models has been limited by its short half-life, lack of data on plasma levels and therapeutic effect, species specific effects of the protein. Here we report novel models to assess APC function in vivo. Both murine (m) and human (h) protein C was first engineered by introducing an extra cleavage site for the intracellular protease-cleavage enzyme (PACE/furin), which results in secretion of active forms of PC. Secondly, to overcome the time-consuming and expensive transgenic technology, we use adeno-associated viral (AAV) to ensure continuous expression of APC forms. Gene transfer was hepatocyte-restricted by using a liver-specific promoter. Following portal vein delivery of vectors, APC were monitored using aPTT-based and species-specific ELISA capture assays. Six weeks post-injection, three cohorts of mice (n=19) expressed hAPC at levels of 80±7, 160±27 and 260±23ng/ml, in a dose-dependent manner, and their respective aPTT values were 24±0.8, 27±1.5 and 31±1.8sec. These aPTT were higher than baseline values (p<0.05). At doses tested, mice injected with mAPC showed functional levels of 7±0.7, 14±2 and 83±2ng/ml, which resulted in aPTT values of 27±1.3, 30±0.2 and 36±1.4sec, respectively and differ from baseline data (p<0.01). Thus, mAPC at levels comparable to the hAPC (80ng/ml) showed prolonged clotting times (36 vs. 24sec, p<0.02). Only by increasing hAPC by 3-fold (260ng/ml), the aPTT values reached those of mAPC. Mice were further challenged by tail clipping assay. Blood loss was increased 2-fold in mice with highest APC levels (260ng/ml, p<0.03) compared to controls. Similar blood loss was observed in mice expressing 3-fold lower mAPC levels (83ng/ml). Anti-thrombotic properties of APC were first tested at microcirculation level by real-time imaging of thrombus formation upon laser-induced injury. In hAPC-treated mice at levels of 80ng/ml, we observed 19 thrombi/29 injury sites (66%), whereas among those with APC levels of 260ng/ml thrombus formation was detected in only 8% (2/24 sites). Interestingly, expression of mAPC at levels of 83ng/ml resulted in substantial reduction of clotting formation (5 thrombi/45 sites, 11%). Exposure of carotid artery to FeCl3 failed to induce vascular occlusion in all hAPC-injected mice (n=9). However, 1/6 mouse expressing mAPC (83ng/ml) showed vessel occlusion, but the remained mice presented either transient clot or no occlusion. In conclusion, both murine and human APC can be efficiently expressed at a range of levels in murine models. Murine APC showed a higher anticoagulant active than human APC at both in vitro and in vivo assays. However, we also demonstrate species-related differences in the protective antithrombotic effects. Murine APC is more effective in the laser-induced injury, characterized by heat damage to a limited region, an injury model likely induced by inflammation. In this latter model, it is likely that mAPC by providing both anticoagulant and antiinflammatory effects have enhanced in vivo functions. Thus, we demonstrate the feasibility and the potential of these models in assessing in vivo effects of APC.

Increasing Exposure of the Petrous Internal Carotid Artery For Revascularization Using The Transzygomatic Extended Middle Fossa Approach: Acadaveric Morphometric Study

When internal carotid artery (ICA) sacrifice is planned in the management of difficult tumors or aneurysms at the cranial base, the petrous ICA may be a useful site for anastomosis for interpositional vascular bypass. However, exposure of the artery and performing an anastomosis in this region may be technically challenging because of the narrow working corridor. The authors describe a transzygomatic extended middle fossa approach that maximizes the exposure of the petrous ICA for performing the difficult anastomosis. Bilateral dissections were performed on eight silicone-injected cadaveric head specimens. Exposure of the entire petrous ICA (horizontal segment, genu, and vertical segment) using the transzygomatic extended middle fossa approach was performed by the following steps. A frontotemporal craniotomy was performed followed by a zygomatic osteotomy. The temporal lobe dura was elevated extradurally to expose the posterior cavernous sinus and floor of the middle fossa. The middle fossa rhomboid was identified, which is bordered by V3 anteriorly, the GSPN laterally, the arcuate eminence posteriorly, and the petrous edge medially. Bone drilling was performed in the middle fossa rhomboid and Glasscock's triangle with care not to violate the cochlea. The horizontal and vertical segments of the petrous ICA were skeletonized entirely and mobilized from carotid canal. The V3 segment of the trigeminal nerve was retracted anteriorly to obtain more distal exposure of the ICA. An osteoplastic bone flap of the middle fossa floor lateral to the ICA was removed to increase the working space. A morphometric analysis was performed, quantifying the petrous ICA exposure, the surgical working corridor, and the angles of exposure. On average, the length of the horizontal petrous ICA exposed was 9.2 +/- 1.0 mm (range, 8.0-11.0 mm). Anterior retraction of V3 provided an additional 4.3 +/- 0.4 mm of carotid exposure (46.7% increase; P < 0.05). The length of the genu was on average 3.6 +/- 0.4 mm (range, 3.0-4.0 mm), and the length of the vertical segment of the petrous ICA was 13.1 +/- 2.0 mm (range, 10.0-15.0 mm). The average depth of the petrous ICA from the outer surface of the temporal bone was 30.6 +/- 1.1 mm (range, 30.0-33.0 mm) at the V3-ICA junction and 27.2 +/- 0.7 mm (range, 26.0-28.0 mm) at the ICA genu. The average diameter of the inner working corridor was 24.2 +/- 3.0 mm (range, 21.5-30.0 mm). Removal of the zygoma increased the outer working corridor from an average distance of 24.4 +/- 3.8 mm to 33.4 +/- 3.4 mm (36.9% increase in exposure; P < 0.05). The average angle of exposure was 66.5% greater (P < 0.05) with zygomatic arch removal (39.3 +/- 4.9 degrees) than without zygomatic arch removal (23.6 +/- 2.7 degrees). The transzygomatic extended middle fossa approach provides a wide surgical corridor for maximal exposure of the petrous ICA with minimized temporal lobe retraction. This large exposure facilitates vascular anastomoses at the petrous ICA and provides working room to maneuver instruments. The middle fossa rhomboid is a key landmark to identify the petrous ICA and to avoid neuro-otologic structures.

Exposure of the Cervical Internal Carotid Artery: Surgical Steps to the Cranial Base and Morphometric Study

Several studies have reported on approaches to increase exposure of the distal cervical internal carotid artery (ICA), but these studies have neither systematically addressed the anatomic aspects nor quantified the additional exposure of each maneuver. We describe surgical steps to expose the ICA region, quantify the additional exposure of each operative step, and discuss ways to minimize surgical morbidity. The ICA was exposed in 10 formalin-fixed cadaveric heads using the following four steps: 1) anterior sternocleidomastoid approach, 2) retroparotid dissection and division of the digastric muscle, 3) section of the styloid apparatus, and 4) mandibulotomy. After completion of each step, the most distal level of ICA exposure was marked with a hemoclip and segment lengths were measured between each clip. Sectioning of the digastric muscle and sectioning of the styloid apparatus provided the most significant exposure of the ICA (14.15 and 15.08 mm, respectively) with minimal risks. Mandibulotomy added 10.20 mm in length and 20.65 degrees in width, but is a maneuver that must be weighed against the heightened risk of morbidity. Surgical exposure of the distal cervical ICA is associated with relatively high morbidity that increases with higher levels of exposure. Staged maneuvers have been shown to increase ICA exposure, especially in our systematic approach. The number of steps required varies depending on the level of lesion. Complete understanding of the surgical anatomy is essential to minimize surgical morbidity and to develop surgical expertise.

Potent free radical scavenger, edaravone, suppresses oxidative stress-induced endothelial damage and early atherosclerosis

Objective Effects of potent free radical scavenger, edaravone, on oxidative stress-induced endothelial damage and early atherosclerosis were investigated using animal models and cultured cells. Methods and results Endothelial apoptosis was induced by 5-min intra-arterial exposure of a rat carotid artery with 0.01 mmol/L H 2O 2. Edaravone treatment (10 mg/kg i.p.) for 3 days suppressed endothelial apoptosis, as evaluated by chromatin staining of en face specimens at 24 h, by approximately 40%. Similarly, edaravone dose-dependently inhibited H 2O 2-induce apoptosis of cultured endothelial cells in parallel with the inhibition of 8-isoprostane formation, 4-hydroxy-2-nonenal (4-HNE) accumulation and VCAM-1 expression. Next, apolipoprotein-E knockout mice were fed a high-cholesterol diet for 4 weeks with edaravone (10 mg/kg i.p.) or vehicle treatment. Edaravone treatment decreased atherosclerotic lesions in the aortic sinus (0.18 ± 0.01 to 0.09 ± 0.01 mm 2, P < 0.001) and descending aorta (5.09 ± 0.86 to 1.75 ± 0.41 mm 2, P < 0.05), as evaluated by oil red O staining without influence on plasma lipid concentrations or blood pressure. Dihydroethidium labeling and cytochrome c reduction assay showed that superoxide anions in the aorta were suppressed by edaravone. Also, plasma 8-isoprostane concentrations and aortic nitrotyrosine, 4-HNE and VCAM-1 contents were decreased by edaravone treatment. Conclusions These results suggest that edaravone may be a useful therapeutic tool for early atherosclerosis, pending the clinical efficacy.

Modified technique to create morphologically reproducible elastase-induced aneurysms in rabbits

The purpose of this study was to create morphologically reproducible elastase-induced model aneurysms in rabbits. We created 120 elastase-induced aneurysms in rabbits using two different methods: the standard technique (group 1, n=62) and a modified technique (group 2, n=58). In the standard technique a small cutdown with a focal area of exposure of the mid-right common carotid artery (RCCA) was employed, while in the modified technique the RCCA was completely exposed to its origin. We measured aneurysm sizes (neck diameter, width and height) in the two groups. The aneurysm sizes were compared between the two groups using Student's t test, and the standard deviations of the aneurysm sizes were compared between the groups using the F test. The mean aneurysm neck size, width and height in group 1 were 3.4+/-1.2 mm, 3.8+/-1.0 mm and 8.0+/-1.7 mm, respectively, and in group 2, were 3.2+/-0.9 mm, 3.7+/-0.6 mm and 9.1+/-1.8 mm, respectively. The differences in mean aneurysm neck and width between the two groups were not significant (P>0.05). However, there were significant differences in the standard deviation of these two parameters between the two groups (P<0.05 and P<0.01, respectively). The mean aneurysm height in group 2 was larger than in group 1 (P<0.001), but no significant difference in the standard deviation of this parameter between the two groups was found (P>0.05). The results indicate that more consistent aneurysm diameters can be created using the modified technique.

Transoral Approach to the Superomedial Parapharyngeal Space

To present our early experience with the transoral approach to the superomedial parapharyngeal space (PPS) and describe our technique for removal of these neoplasms. Consecutive case series by one author (Y.D.). Eight patients with various neoplasms of the superomedial PPS were retrospectively reviewed for type of neoplasm, size, success with the transoral approach, need for conversion to another approach, length of hospitalization, and complications. The transoral approach described herein safely allowed for en bloc resection of benign neoplasms with intraoperative control and exposure of the internal carotid artery. The most common pathology encountered was that of schwannoma. All patients were started on liquid diet on postoperative day 1. Average length of stay was 3.2 days (range, 2 to 5). Mean tumor size was 3.3 cm (range, 1.5 to 7 cm). No significant complications were felt to be related to the approach itself and visualization was felt to be excellent in each case without the need for conversion to a more extensive approach. The transoral approach safely provides access to superomedial PPS lesions with decreased morbidity compared with traditional approaches. This technique is indicated for neoplasms with benign appearance on preoperative imaging or fine needle aspiration. This approach alone may not provide adequate access for resection of malignant lesions especially those with extension intracranially or to more inferior or laterally placed lesions of the parapharyngeal space. C-4.

ANG II-induced neointimal growth is mediated via cPLA2- and PLD2-activated Akt in balloon-injured rat carotid artery

Angiotensin II (ANG II) promotes neointimal growth in the balloon-injured rat carotid artery. However, the mechanism by which ANG II stimulates neointimal growth during vascular injury is not known. In cultured vascular smooth muscle cells, ANG II activates Akt through cytosolic phospholipase A2 (cPLA2)-dependent phospholipase D2 (PLD2). This study was conducted to determine whether ANG II-induced neointimal thickening is mediated via cPLA2- and PLD2-activated Akt in balloon-injured rat carotid arteries. ANG II-stimulated neointimal growth was inhibited by exposure of the injured carotid arteries to an adenovirus containing a dominant negative Akt mutant (intima-to-media ratio from 3.01 +/- 0.31 to 1.44 +/- 0.14, P < 0.01) or a retrovirus containing cPLA2 small interfering RNA (siRNA; intima-to-media ratio from 3.01 +/- 0.31 to 1.16 +/- 0.36, P < 0.001) or PLD2 siRNA (intima-to-media ratio from 3.01 +/- 0.31 to 1.33 +/- 0.11, P < 0.001). The effect of cPLA2 and PLD2 siRNA to reduce the ANG II-induced increase in neointimal thickening was associated with reduced expression of cPLA2 and PLD2 as determined by immunohistochemical analysis in injured carotid arteries. Western blot analysis showed that Akt phosphorylation that was increased by ANG II was inhibited in injured carotid arteries 2 days after exposure to cPLA2 or PLD2 siRNA or in injured arteries isolated after exposure to these agents for 30 min and then placed in tissue culture media for 24 h in the presence of these agents. These data suggest that the ANG II-induced neointimal growth is mediated by the activation of Akt through a mechanism dependent on cPLA2 and PLD2 activation in balloon-injured rat carotid arteries.

Software-Enabled Computed Tomography Analysis of the Carotid Artery and Sphenoid Sinus Pneumatization Patterns

The critical relationship of the carotid artery with the sphenoid sinus has been long established. Sophisticated imaging software in conjunction with three-dimensional high-resolution computed tomography (CT) imaging now facilitates detailed analysis of these anatomic relationships. Siemens VolumeZoom CT scanner was used to obtain high-resolution computed tomography data that was subsequently transferred to the CBYON Suite Doctor Station version 2.6 for analysis. Various surgical planning tools were used for evaluating the CT scans. The relationship of the carotid artery with the sphenoid sinus was delineated. One-hundred twenty-eight sides in 64 cadaveric specimens were reviewed. Pneumatization of the sphenoid sinus was classified into four categories: conchal, presellar, sellar, and postsellar. The incidence of these four types was 4.7, 4.7, 25, and 65%, respectively. Carotid artery exposure was categorized as follows: no exposure, <90 degrees, >90 to <180 degrees, and >180 degrees. The incidence of the carotid exposure was 12.5, 32.8, 50, and 4.7%, respectively. Septal insertions onto the carotid artery were noted in 37.5% and dehiscences in 19.5% of the specimens. Computer-aided CT analysis allows for a detailed study of the critical relationship of sphenoid pneumatization and carotid artery position. Such technology can be invaluable in surgical planning and navigation during endoscopic sinus surgery. In lieu of these findings, sinus surgeons must exercise extreme caution when operating in this region to prevent unintentional injury to the carotid artery.

Endovascular stenting for stenoses in surgically reconstructed brachiocephalic bypass grafts: immediate and midterm outcomes.

To report the use of endovascular stenting for treatment of patients with symptomatic obstruction of brachiocephalic surgical reconstructions. Twenty-two patients (17 men; mean age 65+/-6 years) with 24 symptomatic obstructions of brachiocephalic Dacron bypass grafts (2 aorto-innominate, 9 subclavian-carotid, and 11 carotid-subclavian) were treated with balloon-expandable stents delivered via a percutaneous brachial access or surgical exposure of the common carotid artery. A distal protection device was utilized in the 9 patients with subclavian-carotid bypass grafts. All patients were followed by clinical and Doppler examinations. Procedural success was 100%; 1 (4.5%) patient developed transient intraprocedural aphasia owing to intolerance to the distal protection balloon occlusion. All 22 patients reported complete relief of their presenting symptoms. Over a 29-month follow-up, 3 (13.6%) restenoses were found, but none was due to stent compression. Stenting for obstructed brachiocephalic reconstructions appears to be a safe, effective, and durable therapeutic strategy.

Initial experience with personal digital assistant-based reflectance photoplethysmograph for free tissue transfer monitoring.

Improved microsurgical technique has resulted in a high percentage of successful free tissue transfers. When a tissue transfer fails in the head and neck, however, the results are orocutaneous fistulas, carotid artery exposure, and deformity that adds morbidity, expense, and may delay adjuvant therapy. Postoperative monitoring of tissue perfusion can detect early problems in free tissue transfer that may allow for early intervention and salvage. The authors have demonstrated that reflectance photoplethysmography can detect perfusion changes in free tissue transfer within 5 minutes of a pedicle "insult" intraoperatively. Normative data for viable flaps from various donor sites have been established. The authors now report their initial experience with a newly developed reflectance photoplethysmograph based on a hand-held computer for routine clinical use. Their results are compared with a conventional surveillance protocol that included observation, bleeding to pin prick, and bedside duplex scanning of the vascular pedicle. In a series of 30 free tissue transfers (29 patients), there was one ischemic event (skin paddle loss only), which was detected by the monitor. The monitor was able to predict correctly (one flap) survival of a free tissue transfer even when duplex ultrasonic data were indicative of an absence of perfusion. Personal digital assistant-based photoplethysmography appears to be a promising device for bedside diagnosis of free tissue transfer viability or ischemia.

Head and neck extension-fixation with a head frame for exposure of the distal internal carotid artery in carotid endarterectomy--technical note.

Adequate exposure of the distal internal carotid artery (ICA) for carotid endarterectomy may be difficult to achieve because of the position of the mandible and associated soft tissues. A simple yet effective use of a head frame is described to gain several centimeters of exposure of the distal ICA. The patient's head and neck are fixed in an extension position using a radiolucent head frame. Nasotracheal intubation and secure taping of the chin are also employed to keep the mouth closed and to prevent the mandible from spontaneously hanging down. The head frame tightly fixes the patient's neck, so the mandible does not disturb the surgical field throughout the operation. This simple method maximizes exposure of the distal ICA. The radiolucent head frame also enables intraoperative angiography to confirm the patency of the ICA and the absence of flap formation. This simple technique is useful for exposing the distal ICA.

A new model to evaluate the diet-induced prothrombotic state, using He-Ne laser-induced thrombogenesis in the carotid artery of apolipoprotein E-deficient and low-density lipoprotein receptor-deficient mice.

Epidemiological studies suggest the high fat content of the Western diet to be responsible for atherosclerosis and its thrombotic complications. Despite such a prevailing view, few animal experiments have so far succeeded in demonstrating enhanced thrombogenicity due to a high fat diet. Even a high fat and a very high cholesterol (1%) diet has failed to demonstrate an enhanced thrombotic reaction in rodents and rabbits. The aim of the present study was twofold. First, we wanted to establish a new, sensitive and specific thrombosis model in mice, which can then be used to study the effect of diets. Second, we intended to employ such a thrombosis model in investigations into the effect of high or low fat diets on thrombosis. The technique described uses a laser to induce thrombus formation in the exposed carotid artery of apolipoprotein E-deficient and low-density lipoprotein receptor-deficient mice. Thrombus formation was recorded on video, analysed by computer, and the size of thrombus was calculated by image analysis software. Thrombotic status was evaluated by analysing a total of 61 individual images of the thrombotic reaction, which were taken over 600 s. The severity of atherosclerosis was assessed by image analysis of the stained elastic fibers. Two kinds of diets were used: the Western type, high fat diet contained 20% fat (w/w) and 0.05% cholesterol (w/w); the low fat diet contained 7% fat, without cholesterol. These diets were on the basis of AIN93G and were given to mice for 4 or 8 weeks. The high fat diet significantly enhanced both the thrombotic reaction and the development of atherosclerosis as compared with the low fat diet.

Successful endovascular therapy of a penetrating zone III internal carotid injury

Penetrating injuries to the internal carotid artery in zone III of the neck can be a significant challenge to the operating surgeon. Direct surgical exposure and repair of the internal carotid artery at the skull base can be extremely difficult, and surgical options for treatment of a pseudoaneurysm at this location are limited. We present a case of an 18-year-old man who sustained a single gunshot wound to the distal cervical internal carotid artery that led to a pseudoaneurysm managed with endovascular exclusion. Recent literature on the surgical and endovascular management of distal carotid injuries is reviewed. (J Vasc Surg 2002;36:187-90.)

Vertical Ramus Osteotomy Allows Exposure of the Distal Internal Carotid Artery to the Base of the Skull

Exposure of the distal internal carotid artery (ICA) above the level of the second cervical vertebra can be difficult and often require maneuvers such as division of the digastric muscle or mandibular subluxation. These techniques increase exposure but may not provide adequate access. We report a series of eight cases in which vertical division of the mandibular ramus provided access of the ICA up to the base of the skull. Over the last 10 years, eight patients underwent vertical ramus osteotomy (VRO) to aid in distal ICA exposure. Preoperative arteriography revealed ICA lesions within 1.5 cm of the skull base. Indications for surgery were compelling and included gunshot wounds to zone III of the neck (n = 2), transient ischemic attack (n = 2), and preocclusive stenosis (n = 4). VRO was performed through a standard vertical neck incision and was created from the depth of the sigmoid notch to the angle of the mandible after elevating the masseter muscle from the bone. Miniature titanium plates were used to reapproximate the mandible after endarterectomy (n = 5), bypass (n = 2), or arterial repair (n = 1). We found that VRO provides reliable exposure of the distal ICA up to the base of the skull. Unlike mandibular subluxation, it requires no pre-incision preparation, thus mandibulotomy can be performed after carotid artery dissection has begun, and may even be avoided. VRO is especially useful when carotid artery pathology unexpectedly extends beyond the usual field of exposure. Work on the carotid artery at the skull base is associated with significant complications and should be reserved for compelling indications.

Vertical Ramus osteotomy allows exposure of the distal internal carotid artery to the base of the skull

Vertical Ramus osteotomy allows exposure of the distal internal carotid artery to the base of the skull

大型破裂脳動脈瘤の手術手技と手術成績

To elucidate clinical characteristics of ruptured large aneurysm whose diameter ranges from 15 to 24mm, surgical procedures and surgical outcomes of cases with large aneurysms were compared with those with small or giant aneurysms. This study included 827 small aneurysm cases, 62 large aneurysm cases and 16 giant aneurysm cases. Surgical procedures required were significantly different among those groups. Frequency of temporary clip usage, multiple clipping, and cervical carotid artery exposure in the carotid artery aneurysm was related to the size of aneurysms. Surgical outcome of good presurgical clinical grades was poorer in the large aneurysm group than in the small aneurysm group.This difference appeared to be based on surgical procedures resulting in vascular damage in large aneurysm cases. We should note that some techniques required in giant aneurysm surgery are also necessary for some large aneurysm cases, especially in cases of internal carotid artery aneurysms or vertebrobasilar artery aneurysms. Sophisticated surgical techniques, including skull base approaches, or alternative procedures like endovascular treatment should be considered even for large aneurysm cases to improve surgical results, especially in good clinical grade patients.