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Yuzo Sasaki

Publications and source records attributed to Yuzo Sasaki.

7 recordsLinked to original sources
PubMed2005

Surface-emitted terahertz-wave difference-frequency generation in two-dimensional periodically poled lithium niobate.

We report on the demonstration of surface-emitted terahertz- (THz-) wave difference-frequency generation from two-dimensional (2D) periodically poled lithium niobate (PPLN). The two orthogonal periodic structures individually compensate for both the phase mismatch of the launched lasers and the generated THz wave. Tunable 1.5-1.8 THz wave generation with a bandwidth of 10-GHz was obtained by use of two 2D PPLN crystals. We also confirmed that THz waves were simultaneously generated into two opposite directions, which suggests the possibility of higher THz-wave output power.

Journal Article↗
PubMed2004

Are there significant benefits of minimally invasive endoscopic thyroidectomy?

Minimally invasive surgery using endoscopic vision is widely employed for the treatment of thyroid diseases. We have performed endoscopic thyroidectomy by the axillary approach (axillary approach) and video-assisted thyroidectomy via a 3 cm cervical incision (video-assisted approach). In this study, we evaluated the efficacy of these two procedures. Each procedure was performed in 20 consecutive consenting patients. The degree of invasiveness after surgery was compared using postoperative results. The amount of pain and satisfaction with surgery was evaluated by grade (1-5) using a patient questionnaire. All thyroidectomies were completed successfully. No recurrent laryngeal nerve palsies occurred. Operating time for the video-assisted approach was significantly shorter than that for the axillary approach (p < 0.01). The amount of pain for the axillary approach on 1, 3, and 5 days after operation, respectively, was graded 3.2+/-0.7, 2.1+/-0.6, and 1.6+/-0.7 compared to 2.7+/-1.1, 1.7+/-0.7, and 1.1+/-0.2 for the video-assisted approach. The postoperative course was significantly less painful in patients undergoing the video-assisted approach on postoperative days 3 and 5 (p < 0.01). The degrees of satisfaction for the axillary approach and the video-assisted procedure were 1.2+/-0.4 and 2.4+/-1.0, respectively (p < 0.01). The video-assisted approach is less "invasive" than the axillary approach, but the axillary approach may be indicated for patients who are anxious about the visible cosmetic results.

Adult↗
PubMed2003

Clinical benefits in endoscopic thyroidectomy by the axillary approach.

BACKGROUND: Surgical treatments for thyroid diseases require skin incisions that can result in prominent scars, complaints resulting from adhesions, hypesthesia, and paresthesia in the neck. We have developed an endoscopic thyroidectomy using an axillary approach. In this article, we compare our original technique with conventional open surgery from the aspects of surgical invasiveness and patients' complaints after surgery. STUDY DESIGN: Each procedure was performed in 20 patients with follicular tumors. The two groups were similar for age, gender, and the mean diameter of the thyroid tumor. No statistically significant difference in the final pathological diagnosis was found between the two groups. Surgical invasiveness and patients' complaints after surgery were compared using results of the operation and a questionnaire. RESULTS: The operating time for open surgery was significantly shorter than that for endoscopic surgery (p < 0.01). In the endoscopic surgery group, the patient questionnaires revealed that 4 patients had severe anterior chest pain on the first postoperative day. The postoperative pain decreased after, and we could not find any difference between the two groups with regard to postoperative pain. Three months after surgery, one patient who had received an endoscopic procedure complained of slight hypesthesia, and none of the patients complained of discomfort while swallowing. Among the patients who underwent open surgery, 13 patients (65%; p < 0.01) complained of hypesthesia or paresthesia and 6 patients (30%; p < 0.05) complained of discomfort while swallowing. All of the patients treated using the endoscopic procedure were satisfied with the cosmetic results, but 15 patients who underwent open surgery complained of unsatisfactory cosmetic results (p < 0.01). CONCLUSIONS: The incidence of postoperative complaints after endoscopic surgery is considerably lower than that after open surgery.

Adult↗
PubMed2002

Direct mini-incision thyroidectomy.

We recently developed a new surgical technique for carrying out thyroidectomy, to minimize surgical invasiveness and improve the cosmetic result. Our procedure differs from conventional thyroidectomy in requiring a 3-cm skin incision and no raising of the skin flap. Since this technique decreased tissue trauma by obviating unnecessary neck exploration, hypesthesia or paresthesia in the neck and discomfort while swallowing, related to a large skin incision and raising of the skin flap, are minimized. Since thyroidectomy is performed after delivering the thyroid gland through the small skin incision, sufficient exposure for dissection of the pretracheal and paratracheal space can be obtained. Therefore, injuring the recurrent laryngeal nerve and the parathyroid gland can be avoided. Although the number of patients that we have treated in this manner is still small, we believe that our new procedure constitutes a useful surgical treatment for patients with thyroid disease.

Adult↗
PubMed2002

Direct mini-incision parathyroidectomy.

We describe our technique for performing a mini-incision parathyroidectomy in patients with hyperparathyroidism. Since our procedure differs from conventional parathyroidectomy in requiring a 2- or 3-cm skin incision and no raising of skin flap, this technique resulted in a good cosmetic status and less invasiveness. Hypesthesia or paresthesia in the neck and discomfort while swallowing related to a large skin incision and raising of skin flap are minimized. Although the cosmetic results of endoscopic techniques are better than those of our procedures, endoscopic instruments remain traumatic, can easily inflict iatrogenic lesions to parathyroid adenomas and enhance the risk of tumor cell exfoliation, especially if the parathyroid adenoma is manipulated by the instruments. Our surgical procedure can be less technically demanding and time-consuming. Although the number of patients whom we have treated in this manner is still small, we believe that our new procedure constitutes a useful surgical treatment for hyperparathyroidism.

Humans↗