Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3810_Библиотеки_им_академика_М_И_Перельмана

at a slower rate than intermediate-sized ones [8]. CBTs are characteristically extremely vascular, secrete catecholamines on rare occasions, and are usually benign. Microscopically, the tumors reproduce the architecture of the normal carotid body, which is composed of granular epithelioid chief cells and sustentacular supporting cells. When malignant, CBTs metastasize to the local lymph nodes, liver, lung, and bone, although metastases occur in no more than 5% of cases.

detected earlier at smaller sizes, and thereby cra­nial nerve compromise is rare currently. Lastly, a rare functional CBT may produce neuroendocrine secretions causing catecholamine-related symp­toms, such as palpitations, headaches, hyperten­sion, tachycardia, or ushing.

for atherosclerotic carotid disease, operations for CBT can be bloodier, obscuring the surgical eld. Additionally, the size of the tumor may distort normal anatomic path of the nerves. Most com­monly injured cranial nerves include the vagus and hypoglossal [20]. The conuence of multi­ple cranial nerves along the lateral border of the distal ICA (VII, IX, X, and XII) makes this area particularly treacherous and thus has spurred the development of alternate dissection techniques as described previously. A longer dissection time and need for additional exposure can put nerves at risk for retractor injury. Routine exposure of the vagus (X), hypoglossal (XII), and spinal accessory (XI) (if anticipated to be in the vicin­ity) is undertaken. We are cautious about deep retraction on the mandible to avoid injury to the marginal mandibular branch of the facial nerve. Posteriorly, care is taken to identify the cervical sympathetic chain to avoid resultant Horner’s syndrome. Importantly, the risk of cranial nerve injury can be mitigated by resecting tumors early rather than allowing them to enlarge. For every 1cm the tumor grows toward the skull base, the risk of cranial nerve injury is increased about 1.5 times [19].