Yousuke Takeuchi

Contralateral external carotid-middle cerebral artery bypass for carotid artery resection

Resection of the common carotid or internal carotid artery is occasionally unavoidable in cases of advanced head and neck carcinoma with carotid artery involvement. To prevent the consequent decrease in cerebral perfusion, we have developed a contralateral external carotid‐middle cerebral artery bypass grafting technique. From 1990 through 1995, six patients with advanced head and neck cancer involving the carotid artery underwent total tumor resection combined with vascular reconstruction using the contralateral external carotid‐ middle cerebral artery bypass grafting. No bypass‐related complications occurred in any patient postoperatively. Cerebral hemodynamics after surgery indicated that this bypass graft worked steadily over a long term and supplied sufficient volume of blood to the cerebral cortex on the opposite side in every case.

Differential diagnosis of cervical lymph nodes in head and neck cancer by ultrasonography

OBJECTIVE Determination of whether an enlarged cervical lymph node is metastatic or not is clinically important in head and neck oncology. Differential diagnosis of the lymph node, however, is still a diagnostic problem. The purpose of this study is to clarify the ultrasonographic findings of the metastatic lymph nodes of head and neck squamous cell carcinoma and to establish the criteria. METHODS We investigated 36 metastatic lymph nodes in head and neck squamous cell carcinoma and 24 non-metastatic nodes in benign disease with a 10-MHz transducer. We examined the size, shape, and internal echo (echo level, punctate bright echogenic spots, hilus echogenic line, cystic pattern) of these nodes. Based on this investigation, we evaluated 70 lymph nodes from 25 other patients by ultrasonography. RESULTS The short axis diameter and shape of metastatic nodes were larger and rounder than those of non-metastatic ones. Of the metastatic nodes, 69% showed hypoechoic and 31% isoechoic levels, and 78% exhibited punctate bright echogenic spots. Of the non-metastatic nodes, 92% showed hypoechoic and 8% isoechoic levels, and none of them showed the spots. The hilus echogenic line was not present in any metastatic node, but it was seen in 58% of non-metastatic ones. Of the metastatic nodes, 19% exhibited a cystic pattern; none of the non-metastatic nodes showed the pattern. According to our criteria based on these results, the accuracy rate was 98.6% (69/70). The sensitivity and specificity were 97.2% (35/36) and 100% (34/34), respectively. The false positive rate and the false negative rate were 0% (0/70) and 1.4% (1/70), respectively. CONCLUSION Internal echo findings and shape of lymph nodes can be an important diagnostic tool, and our ultrasonographical criteria of the lymph nodes are very useful for the differential diagnosis of the cervical lymph nodes.

Thallium-201 single-photon emission tomography in the treatment follow-up of nasopharyngeal carcinoma

In order to assess the usefulness of thallium-201 single-photon emission tomography (SPET) in the treatment follow-up of nasopharyngeal carcinoma (NPC), a total of 75201Tl SPET studies were performed in 18 patients with histologically proven NPC. The findings were compared with those of magnetic resonance imaging (MRI) before and after therapy. Four patients received radiotherapy alone while the other 14 received concurrent chemo-radiotherapy. Treatment response was classified as complete (CR) or partial (PR) based on the findings of MRI and201Tl SPET. Intense201Tl uptake by the tumour was seen in all 18 patients before treatment. After treatment, MRI showed seven CRs and 11 PRs, whereas201Tl SPET showed 13 CRs and five PRs. In 12 patients, the results of201Tl SPET were in agreement with those of MRI. In six patients MRI showed PR but201Tl showed CR. Follow-up (mean 10.6 months) MRI and201Tl SPET studies of these six patients revealed that tumour gradually decreased and finally vanished in three patients. This preliminary study indicates that201Tl SPET has potential in the assessment of early response to treatment of patients with NPC when compared with MRI.

Hemodynamic Changes in the Head and Neck after Ligation of the Unilateral Carotid Arteries: A Study Using Color Doppler Imaging

For evaluation of the hemodynamics of the collateral circulation to the ligated external carotid artery (ECA) region, we measured the blood flow direction and volume in branches of the ECA in patients with unilateral carotid artery ligation before and during digital suppression of the common carotid artery (CCA) on the ligated and nonligated sides with color Doppler imaging and angiography. The main collateral pathway to the ligated ECA region was the ipsilateral occipital artery through Richters anastomosis from the vertebral artery in the case of unilateral ECA ligation, and was the contralateral carotid artery in the case of unilateral CCA, ECA, and internal carotid artery resection. The superior and inferior labial arteries were important as the collateral pathway from the contralateral ECA.

Differential diagnosis of pulsatile neck masses by Doppler color flow imaging.

A pulsatile neck mass (PNM) requires careful judgment in its evaluation, and it is difficult and inaccurate to diagnose a PNM only by physical examination, even though a thrill or bruit is present. Doppler color flow imaging (DCI) was performed as an initial evaluation in nine patients with PNMs. Intravenous digital subtraction angiography, intra-arterial angiography, X-ray computed tomography, and magnetic resonance imaging were performed in selected cases. The DCI revealed seven vascular masses (three tortuosities of the common carotid artery, two tortuosities of the brachiocephalic artery, one pseudoaneurysm, and one traumatic arteriovenous fistula) and two nonvascular masses (one neurofibroma and one metastatic lymph node). The clinical diagnoses of all the vascular masses were defined by DCI. In nonvascular masses, fine-needle aspiration biopsy could be performed relatively safely and accurately by monitoring the feeding artery or the common carotid artery by DCI. This method was quite useful for the initial evaluation in the differential diagnosis of PNMs.

Basal cell adenocarcinomas of the submandibular and parotid glands recognized simultaneously report of a case.

Basal cell adenocarcinomas (BCAC) of the major salivary glands are rare tumors. We experienced a case of BCACs that were recognized simultaneously in the submandibular and parotid glands. The case like this has not been reported previously. We present the case and discuss clinicopathologically the relation between the both tumors. Macroscopically, there was no direct infiltration between the both tumors. Microscopically, neural and perineural invasion were not found in both tumors. Distant hematogenous metastasis to other organs was not found. The fact that the parotid tumor had strong necrotic change and had no nodal structure suggests that the metastatic node had been rapidly enlarged beyond the size of the normal lymph node. It is reasonable to suppose that the submandibular tumor is a primary lesion and the parotid tumor is a metastatic lymph node.