Internal carotid artery loop: an uncommon cause of parapharyngeal tumor

The parapharyngeal space-occupying lessions may develop from any of the structures located inside it. Uncommon although possible ethiologies for them are anatomic variations of the course of the internal carotid artery. These anatomic variants mainly arise from degenerative, mostly age-amplified, causes and lead to elongations, angulations, kinking and tortuosities in the course of the vessel that appear as impressions or protusions of the pharyngeal wall. Utherly unfrecuently lead to loops that may show as large parapharyngeal tumors. This fact should be noticed previously to any invasive procedure to be performed on the patient specially when evidenced in concommitance with an infectious process at the moment of diagnosis. A case of an impressive internal carotid artery loop that conditioned an important parapharyngeal mass in a patient with an associated pharyngeal infection is reported to warn about this rare parapharyngeal space-occupying condition and its potential danger.     

Aneurysm of the extracranial carotid artery

Aneurysms of the extracranial carotid artery are rare vascular lesions. These aneurysms usually present to the otolaryngologist or vascular surgeon as a cervical or parapharyngeal pulsatile mass. Rupture and hemorrhage are unusual complications. Central nervous system symptoms secondary to embolism or thrombosis, however, are relatively common. Because of these serious complications, surgical resection of the aneurysm with restoration of arterial continuity is the treatment of choice. We describe herein three cases of the extracranial carotid aneurysm treated at the Mie University Hospital, Tsu, Japan, in the past two years. Surgical treatments include end-to-end anastomosis, saphenous vein autograft replacement, and direct closure utilizing an internal shunt, respectively, after resection of the aneurysm. In all patients, the postoperative course was uneventful, and angiography six weeks after the operation demonstrated good blood flow through the repaired artery.     

Extracranial internal carotid artery pseudoaneurysm

Extracranial internal carotid artery aneurysms are very uncommon entities. We present the case of a young girl who was transferred to our institution after development of a neck mass after Quincy tonsillectomy. The literature on extracranial carotid artery aneurysms is reviewed and reported.     

Post-traumatic asymptomatic saccular aneurysm of the internal carotid artery

A patient presented with mild upper airway obstruction after being shot from behind through the neck and soft palate. Two days later he developed palsies of the IXth to XIIth cranial nerves inclusive on the traumatised side. These palsies resolved spontaneously after three weeks. Further investigation revealed the presence of a saccular aneurysm of the internal carotid artery. The internal carotid artery was ligated after gradual closure for three days using a Preston clamp.     

Variations of the anatomical position of the internal carotid artery as an important differential diagnosis of parapharyngeal tumors

PATIENT: A case of a 78-year-old man with globus syndrome is reported who was referred to our department because of a tumor of the right parapharyngeal wall. Radiological and endoscopic examination revealed that the tumor was caused by an extracranial kinking of the right internal carotid artery. DISCUSSION: Variations of the anatomical position of the internal carotid artery in the parapharyngeal space are potentially at risk during routine ENT-procedures such as adenoidectomy and tonsillectomy or during endoscopic procedures with diagnostic biopsies. Data about the frequency of variations of the clinical course of the internal carotid artery dorsolateral of the lateral pharyngeal wall vary in literature from 4% to 66%. By cost-effective ultrasound and duplex-ultrasound, computed-tomography, magnetic resonance imaging with angiography or by conventional angiography a wide variety of different diagnostic imaging methods is available. While coiling of the internal carotid artery is ascribed to embryological malformation, elongation and kinking of the artery are due to atherosclerosis or fibromuscular dysplasia. These variations are often asymptomatic but they can also cause symptoms from globus syndrome to cerebrovascular insufficiency producing ischemic attacks or infarction. This case report emphasizes the clinical importance of variations of the clinical course of the internal carotid artery as a differential diagnosis of parapharyngeal tumors since iatrogenic injuries during routine pharyngeal surgery with disastrous outcome were frequently reported in literature. Unexperienced ENT-surgeons should be warned and experienced ENT-surgeons should be reminded of those dangerous variations.     

螺旋CT三维重建咽旁隙的研究

目的探索螺旋CT扫描成人呈张口位时咽旁隙成像并行多平面重建和三维重建等后处理，为经口入路切除咽旁隙肿瘤提供解剖依据及术前指导。方法选择咽旁隙无占位性病变患者28例，放置张口器后行多层螺旋CT血管成像，应用多平面重建测量茎突长度并统计茎突末端与第一颈椎横突的关系，于颅底层面测量茎突至颈内动脉、下颌骨升支后缘的距离并进行统计学分析。利用容积重现和剪切技术对图像进行三维重建等后处理，观察颈内动静脉走行及是否存在变异移位等。结果茎突长度、茎突根部至颈内动脉、茎突根部至下颌骨升支后缘的平均距离分别为(2.50±0.80)、(1.09±0.26)、(2.27±0.29)cm，侧别、性别方面均无显著性差异（P＞0.05）。78.6%（44/56）茎突末端位于第一颈椎横突或以下，64.3%（36/56）颈内动脉起始部位低于舌骨，12.5%（7/56）咽旁隙段颈内静脉先走行于颈内动脉前方然后再转向后外。结论咽旁隙以茎突至毗邻解剖结构的距离为参考，有助于神经血管的定位。三维重建的图像能清晰地显示颅底、下颌骨升支、茎突、颈内动静脉等咽旁隙周边及内部结构。咽旁隙段颈内动静脉均存在一定的变异率，为模拟手术入路和术中颈内动脉定位提供重要信息。     

鼻内镜下上颌窦入路鼻-颅底区域的解剖学分析

目的创建内镜下经上颌窦入路翼腭窝及颞下窝解剖模型,寻找内镜下咽旁间隙段颈内动脉的定位方法。方法 对100例成人行鼻、颅底CT扫描并用Mimics软件进行三维重建;在重建模型上分别测量犁骨后缘中点至颈内动脉相关解剖标志的角度和距离。同时对6具尸头于鼻内镜下经上颌窦联合入路解剖翼腭窝和颞下窝,以咽鼓管为中心向外、向后逐步暴露并定位咽旁间隙段颈内动脉。结果犁骨后缘中点至破裂孔、颈动脉管外孔、颈静脉孔的角度平均值分别为72.0°、57.6°、54.1°,犁骨后缘中点至以上各孔的距离平均值分别为13.65、31.81、32.5 mm,蝶骨角棘与颈动脉管外口前界平均距离为5.92 mm。结论鼻内镜下经鼻联合上颌窦开窗入路能充分的暴露翼腭窝和颞下窝结构。犁骨后根、蝶骨翼突、蝶骨角棘、卵圆孔和茎突是颈内动脉相关颅底解剖的重要标志;蝶骨角棘、骨性咽鼓管口为颈动脉管外口前界的重要骨性标志,术中不超越该界限有助于减少损伤咽旁间隙段颈内动脉。     

口内径路咽旁间隙的内镜解剖结构

目的 研究口内径路咽旁间隙的内镜解剖结构, 了解颈内动、静脉及后组颅神经等解剖结构的毗邻关系, 为内镜下口内径路咽旁间隙肿瘤切除提供解剖依据。方法 对新鲜尸头5例(共10侧), 进行内镜下经口内径路咽旁间隙解剖。结果 咽上缩肌是进入茎突前间隙的标志, 茎突咽肌、茎突舌肌是进入茎突后间隙的标志, 茎突后间隙包含重要的血管及后组颅神经。结论 内镜下口内径路可充分暴露咽旁间隙的结构, 茎突咽肌、茎突舌肌是保护茎突后间隙的重要解剖标志。颈内动脉位于咽上缩肌的外侧, 靠近咽上缩肌内侧能够保护颈内动脉。     

Extracranial internal carotid artery aneurysm presenting as symptomatic hypoglossal and glossopharyngeal nerve paralysis

Aneurysms of the extracranial portion of the internal carotid artery are rare, particularly in young patients. They usually develop following trauma, or secondary to infection involving the parapharyngeal space that extends to the vessel wall. This is a case of an internal carotid artery aneurysm presenting acutely following chiropractic neck manipulation with hypoglossal and glossopharyngeal nerve palsy. The imaging findings and subsequent operative management are described.     

Evaluation of safe surgical treatment of peritonsillar abscess using computed tomography

With the development of new antimicrobial agents, the incidence of peritonsillar abscess (PTA) is on the decline. PTA is still often encountered in general practice, however, where it requires immediate diagnosis and treatment. Because the internal carotid artery runs medially to the medial parapharyngeal space, damage to nearby vascular or other structures is a surgical risk of PTA. We used contrast computed tomography (CT) from PTA patients to investigate the anatomical relationship between the abscess and parapharyngeal space, and to determine safe surgical sites. We observed 31 patients with PTA--19 men and 12 women--between February 1997 and April 1999, all examined by contrast CT and undergoing drainage or incision. The average age was 30.7 years (range: 12-54 years). The abscess was on the right side in 20 cases and on the left side in 11. We determined the sites of the abscess and carotid artery, internal jugular vein, and surrounding soft tissue density area including nerves in the parapharyngeal space based on the angle and distance from recognizable anatomical structures in CT scans. The anterior margin of the parapharyngeal space was 29 +/- 5 mm posterior from the upper posterior alveolar margin. The medial margin of that space was at 15 +/- 2 degrees laterally from the midline of the incisors, and 24 +/- 4 mm laterally from the midline sagittal plane. The internal carotid artery was located medially to the parapharyngeal space, running on the sagittal plane containing the upper posterior alveolar margin. The distance from the anterior margin of the parapharyngeal space to the posterior wall of the PTA was 9 +/- 4 mm, and the distance to the anterior wall of the abscess (including the pharyngeal mucosa) was 31 +/- 5 cm. The relationship between the upper posterior alveolar margin and midline sagittal plane was useful for determining the site of the parapharyngeal space. Because the internal carotid artery is located on the same sagittal plane as the upper posterior alveolar margin, when conducting drainage or incision of PTA, we should advance sagittaLly from the point of incision to a depth of no more than 20 mm. If the tip of the instrument is kept medial to the sagittal plane of the upper posterior alveolar margin, effective treatment should be achievable without the risk of vascular damage.     

Rupture of the internal carotid artery pseudoaneurysm resulting from fungal sinusitis

Although vasculitis due to infection with fungi, including Aspergillus, causes aneurysm formation, reports of internal carotid artery aneurysm formation resulting from fungal sinusitis are few. We report on a patient who experienced massive epistaxis from rupture of an internal carotid artery pseudoaneurysm, caused by fungal sinusitis. We treated the aneurysm with endovascular coil embolization, followed by endoscopic sinus surgery to remove the fungal mass. Intraoperative findings included a torn internal carotid artery and exposure of the coil to the sinus. Performing endoscopic sinus surgery before the embolization procedure would have increased the risks of massive intraoperative bleeding and mortality. Even after achieving hemostasis, serious sequelae, such as cerebral infarction, might occur. In this type of case, otorhinolaryngologists and neurosurgeons should collaborate, and an aneurysm should be treated before endoscopic sinus surgery. Although the treatment strategy for fungal internal carotid artery aneurysms is controversial, this case suggested the use of the embolization procedure followed by endoscopic debridement and antifungal therapy to treat a pseudoaneurysm of the internal carotid artery caused by fungal sinusitis.     

Erosive parapharyngeal space teratoma

An erosive teratoma of the parapharyngeal space is described. Our patient at three months of age presented with an eight-week history of torticollis. Diagnosis was strongly suggested by CT scan which clearly demonstrated bony, fluid and intermediate densities suggestive of a teratoma. The tumor had eroded the petrous bone with inferior extension to the level of the hyoid cartilage. An angiogram revealed compromise of the internal carotid artery at the skull base. Surgical resection at five months removed the tumor from the right parapharyngeal space and included a portion of the petrous bone involving the contents of the middle ear and extending to the base of skull. All vital structures including the facial nerve, carotid artery and vagus nerve preserved. An intraoperative CSF leak was controlled with a muscle plug. To our knowledge, such an extensive teratoma eroding the petrous bone and base of skull, presenting as a neck mass, is the first reported case in the literature. The value of a CT scan as an aid in diagnosis of this tumor is stressed.     

鼻内镜下咽旁间隙解剖研究

目的采用鼻内镜经鼻径路对咽旁间隙区域的重要血管、神经结构进行解剖,掌握其分布的规律,以寻找用于指导手术有效的解剖标志并测量相关的数据,从而为处理该部位病变的鼻内镜手术提供解剖依据。方法对福尔马林浸泡的尸头4例（8侧）,模拟鼻内镜下鼻径路咽旁间隙进行解剖。对手术入路的安全范围进行评估,并观测手术径路的重要标志和毗邻关系,测量相应的解剖数据。结果经鼻径路咽旁间隙前为咽鼓管,外为翼内板残端,上为蝶窦底、破裂孔,下为后鼻孔下缘,内为头长肌。翼管的长度、咽鼓管峡部与颈内动脉的距离分别为（14．50±1．77）m／n、（11．04±1．08）mm。结论鼻内镜下经鼻径路可以暴露咽旁间隙的茎突前间隙部分,在该区域保护颈内动脉是关键。该径路以颈内动脉（interal carotid artery,ICA）的外口和破裂孔两点连线水平作为上界,相对安全地暴露ICA的颈段。     

Stent-graft treatment of extracranial internal carotid artery aneurysm

Extracranial internal carotid artery aneurysm is not a frequent finding. Although there are a number of methods used for the treatment of this kind of pathology, every approach should be tailored to the patient. The authors describe the case of a patient with a large extracranial internal carotid artery aneurysm presenting as a tumor of the parapharyngeal space, treated with a stent-graft. The patient remains asymptomatic at the 2-year follow-up. To our knowledge, this type of successful treatment of a carotid aneurysm has been reported only once so far.     

Lateral mandibulotomy: A technique of exposure for penetrating injuries of the internal carotid artery at the base of the skull

Injuries to the internal carotid artery are rare but are frequently fatal or associated with significant neurologic sequelae. Exposure for surgical repair of penetrating injuries to the internal carotid artery at the base of the skull is difficult because of the overlying ramus of the mandible and the facial nerve. In the past, these injuries have been treated by techniques such as occlusion of the artery with a Fogarty balloon catheter, or subluxation of the temporomandibular joint to gain access to the arterial injury. Based on techniques previously reported for extirpation of parapharyngeal space tumors, we describe lateral mandibulotomy for exposure of penetrating carotid artery injuries at the base of the skull. The technique affords relatively rapid and adequate exposure of these injuries allowing ligation, or in selected cases, arterial repair.     

Intratemporal carotid artery bypass in resection of a base of skull tumor

Tumors of the skull base with carotid artery involvement have heretofore required carotid ligation or been deemed inoperable. Two case reports are presented in which en bloc resection of malignant base of skull tumors included removal of a portion of the internal carotid artery. In the first case, the tumor was primarily in the parapharyngeal space and extended to the base of skull. Partial temporal bone resection was carried out to obtain exposure for carotid reconstruction. The second case involved an en bloc temporal bone resection for a recurrent, malignant, mixed tumor that had invaded the carotid canal. Revascularization was achieved in both cases by an autogenous, saphenous vein graft. The patients suffered no postoperative ischemic neurologic sequelae. These are the first known cases of a carotid bypass with distal anastomosis to the intratemporal portion of the internal carotid artery for a malignant base of skull neoplasm. The authors propose this procedure as an alternative to carotid ligation during surgery of tumors of the skull base requiring carotid resection.     

Intracranial carotid catastrophies encountered by the otolaryngologist

Arteriographic studies are utilized to illustrate the presence and document the results of arterial ligation on three intracranial carotid aneurysms. All three aneurysms resulted from trauma, surgical and otherwise, and all presented as otolaryngologic dilemmas. All were successfully controlled by a combined Otolaryngological and Neurosurgical Team employing varying combinations of intra and extra cranial arterial ligations. None developed significant neurological impairments. The two major indications for common or internal carotid ligation are the resection of neoplasm and the control or prevention of hemorrhage. Sixty percent of patients undergoing elective carotid ligation survive these procedures without evidence of neurological sequelae. This uncompromised survival is based upon the presence or rapid development of collateral circulation to the cerebrovascular bed. Further arteriographic studies are employed to illustrate the development of intra and extra cranial collateralization to the internal carotid artery after surgical interruption of the ipsilateral common carotid. The major collateral circuits demonstrated via a case report are as follows: a. from the vertebral artery to the external carotid and hence to the internal carotid; b. from the posterior communicating artery to the internal carotid; and c. from the ophthalmic artery to the internal carotid.     

Extensive squamous cell carcinoma involving the parotid gland and carotid artery a case report.

Squamous cell carcinomas of the parotid gland are very rare. Majority of them will be metastatic with primaries in the head and neck. Very rarely, they can be from unknown primaries or primary parotid tumor itself. We present a case of the Squamous cell carcinoma with extensive local spread to the scalp, skin of the face, parapharyngeal space and causing occlusion of the internal carotid artery. Brief review of literature regarding primary and secondary type of these tumors is also included. Key words: Squamous cell carcinoma, parotid tumors.     

Survival of a patient with endopharyngeal common carotid blow out due to parapharyngeal abscess as an unusual complication of cholesteatoma

Parapharyngeal abscess as a complication of cholesteatoma is an uncommon entity. Endopharyngeal common carotid artery rupture due to parapharyngeal abscess is also uncommon, and these cases usually end fatally. We present a 17-year-old male with parapharyngeal abscess due to cholesteatoma who developed an endopharyngeal common carotid blow out and survived after common carotid ligation without any neurological sequalae.     

A case of bilateral nontraumatic internal carotid aneurysms presenting with recurrent massive epistaxis]

A case of bilateral nontraumatic internal carotid aneurysms presenting with recurrent massive epistaxis was reported. A 37-year-old female complaining of massive epistaxis from the left nostril was admitted to our hospital. After admission, she experienced recurrent massive epistaxis, but had no cranial nerve palsies. Carotid angiography demonstrated an aneurysm of the cavernous portion of the left internal carotid artery partially protruding into the sphenoid sinus. Neck clipping of the aneurysm was unsuccessful, therefore the left internal carotid ligation in the neck was performed with a Selverstone clamp. After the ligation, no rebleeding and neurological deficits occurred. Postoperative carotid angiography showed an aneurysm of the right internal carotid artery at the same site. The carotid angiography of 3 months later and 1 year and 3 months later revealed that the left aneurysm decreased in size and the right one remained unchanged. Twenty-one cases including ours that presented nontraumatic internal carotid aneurysm of the cavernous portion were reviewed. Twelve cases had no cranial nerve palsies, and 7 cases including ours had no other symptoms than massive epistaxis. Because massiveness of epistaxis from an internal carotid aneurysm often threatens one's life, diagnosis should be made by carotid angiography as soon as possible. There are several surgical procedures for such aneurysms. Clipping is the ideal method which can interrupt the blood flow to the aneurysm completely, but it is very difficult to be performed anatomically. Carotid ligation in the neck with little surgical invasion was an excellent method in 7 cases without rebleeding and neurological deficits. Bilateral intracavernous internal carotid aneurysms were found in our case and another case.(ABSTRACT TRUNCATED AT 250 WORDS)