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Dive into the research topics where Takashi Yamaki is active.

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Featured researches published by Takashi Yamaki.


Journal of Vascular Surgery | 2008

Prospective randomized efficacy of ultrasound-guided foam sclerotherapy compared with ultrasound-guided liquid sclerotherapy in the treatment of symptomatic venous malformations

Takashi Yamaki; Motohiro Nozaki; Hiyoyuki Sakurai; Masaki Takeuchi; Kazutaka Soejima; Taro Kono

OBJECTIVE To compare the clinical outcome between ultrasound-guided foam sclerotherapy (UGFS) and ultrasound-guided liquid form sclerotherapy (UGLS) in patients with venous malformations (VM). METHODS Eighty-nine patients with symptomatic VM were treated with ultrasound-guided sclerotherapy. There were 22 males and 67 females with mean age of 14.5 years. The sclerosing agents used were 1% polidocanol (POL) or 10% ethanolamine oleate (EO). POL was injected predominantly into smaller, superficial lesions, whereas EO was used for large, deeper lesions. Foam sclerosing solution was provided using Tessaris method. Patients were randomized to receive either UGFS or UGLS. Post-sclerotherapy surveillance was done at 6 months after last session using duplex ultrasound. Findings obtained by duplex scanning were divided into four groups: (1) disappeared group: the venous space was occluded and was totally shrunk; (2) partially recanalized group: the venous space was partially recanalized and was partially shrunk; (3) totally recanalized group: the venous space was totally recanalized and returned at the same size; and (4) worsened group: the venous space was totally recanalized and became worse. RESULTS Forty-nine patients were treated with UGFS and the remaining 40 were treated with UGLS. There were no significant differences in age and men:women ratio. There was no significant difference in the anatomic distribution of VMs between the two groups. The amount of POL was significantly smaller in patients who were treated with UGFS (P = .022). Similarly, there was a significant reduction in the use of EO in patients treated with UGFS (P = .005). The proportion of VM with total disappearance and partial recanalization was significantly higher in patients treated with UGFS (P = .002). No major complications related to sclerotherapy were encountered in both groups. CONCLUSIONS These findings suggest that UGFS could have greater promise compared with UGLS in the treatment of VMs.


Dermatologic Surgery | 2000

Color Duplex-Guided Sclerotherapy for the Treatment of Venous Malformations

Takashi Yamaki; Motohiro Nozaki; Kenji Sasaki

Background. Although surgical extirpation is the standard method for the treatment of vascular malformations, this procedure often leads to loss of motor function, nerve damage, and massive bleeding if the excision is extensive. Sclerotherapy is an alternative method of treatment for venous malformations. Objective. This study was conducted to assess the effect of color duplex ultrasound‐guided sclerotherapy on venous malformations and the coagulability induced by sclerosing solution. Methods. Twenty‐eight patients with venous malformations underwent percutaneous sclerotherapy by direct puncture under duplex ultrasound guidance. Intravenous catheters were inserted into duplex ultrasound‐confirmed venous spaces and fine plastic tubing filled with normal saline was attached to the needle. When the needle tip was observed to pierce the vein wall, aspiration of the blood confirmed its intraluminal position. The mean volume of 3.6 ml of 3% polidocanol was injected. Subfascial ligation of the lateral marginal venous collector was performed in patients with Klippel–Trenaunay syndrome. D‐dimer (DD) and thrombin‐antithrombin III (TAT) were measured preoperatively and on the first and fifth postoperative days. Results. The head and neck, which was the most common site of venous malformations were involved in 57% of the patients. Venous malformations disappeared in 44% of the patients and decreased in 28%. Localized pain was the most common complication, occuring in 82% of the patients. Sclerotherapy for venous malformations produced significant swelling in 75% of the patients, which required 5–7 days to subside. Significant differences were detected in both DD and TAT concentrations on the first and fifth postoperative days. Conclusions. Color duplex‐guided sclerotherapy was effective in 82% of the patients. This procedure prevents intra‐arterial injection accidents. Although patients with venous malformations showed greater coagulability, no serious thrombotic sequelae were found.


European Journal of Vascular and Endovascular Surgery | 2009

Multiple Small-Dose Injections Can Reduce the Passage of Sclerosant Foam into Deep Veins During Foam Sclerotherapy for Varicose Veins

Takashi Yamaki; Motohiro Nozaki; Hiroyuki Sakurai; Masaki Takeuchi; Kazutaka Soejima; Taro Kono

OBJECTIVE To compare the proportion of foam sclerosant that enters deep veins between multiple injections of <0.5 ml foam per injection and a few injections of >0.5 ml foam per injection. DESIGN & METHODS One hundred and seven patients with superficial venous incompetence were randomised to receive either multiple injections of <0.5 ml 1% polidocanol (POL) -foam (multiple injections) or a few injections of >0.5 ml 1% POL-foam per injection (few injections) for the treatment of varicose tributaries. All patients then received ultrasound-guided foam sclerotherapy for refluxing great saphenous vein (GSV) using 3% POL-foam. Only a single session was allowed per patient in order to standardise treatment. Qualitative ultrasonographic inspection of the foam was carried out during a 5-min period before compression was applied. Post-sclerotherapy surveillance was done at day 3, 2 weeks, 1 month, 3 months, and 6 months. RESULTS Fifty-six limbs in 53 patients were treated with multiple injections and the remaining 56 limbs in 54 patients were treated with a few injections. There were no significant differences in age or male:female ratio between the groups. The mean volume of 1% POL-foam was 2.2 S.D. 0.6 ml (range: 0.7-4.0 ml) in the multiple injections group and 2.5 S.D. 0.6 ml (range: 1.0-4.0 ml) in the few injections group (p=0.003). The mean volume of 3% POL was 1.5 ml (range: 0.7-3.0 ml) and 1.4 ml (range: 0.7-3.0 ml), respectively (p=0.137). Ultrasonographic inspection immediately after sclerotherapy demonstrated that foam was distributed significantly more commonly in the deep veins of patients treated with a few injections (p=0.0003). Two (4%) of the patients treated with a few injections developed migraine during the procedure, but recovered quickly with no further complications. There was no significant difference in the success rate between the groups at 6 months (p=0.257). CONCLUSIONS These findings suggest that multiple small-dose injections can reduce the amount of foam sclerosant and the risk of foam sclerosant entering the deep veins in patients with superficial venous insufficiency.


Journal of The American College of Surgeons | 2002

Comparative evaluation of duplex-derived parameters in patients with chronic venous insufficiency: correlation with clinical manifestations

Takashi Yamaki; Motohiro Nozaki; Osamu Fujiwara; Eika Yoshida

BACKGROUND Quantification of venous reflux is still a matter of debate. Our goal was to compare the duplex-derived parameters between patients with early and advanced chronic venous insufficiency (CVI), and to determine indicative parameters reflecting the progression of CVI. STUDY DESIGN A total of 1,132 limbs in 914 patients with primary valvular incompetence were included. Clinical manifestations were categorized according to the CEAP (clinical, etiologic, anatomic, and pathophysiologic) classification, and the patients were divided into two groups: group I (those with relatively early CVI, C(1-3)E(P),A(S,D,P),P(R)) and group II (those with advanced CVI, C(4-6)E(P),A(S,D,P),P(R)). The distribution of venous insufficiency was determined, and the parameters assessed were the duration of reflux (s), the peak reflux velocity (cm/s), and the flow at peak reflux (mL/s). RESULTS There was no notable difference in overall superficial venous reflux between the groups, and the frequency of isolated deep and perforator incompetence did not differ between the groups. The duration of reflux did not improve the discrimination power between the groups. In contrast, the peak reflux velocity had significant discrimination power at the saphenofemoral junction (p < 0.0001), the saphenopopliteal junction (p = 0.0002), in the greater saphenous vein (p < 0.0001), in the superficial femoral vein (p = 0.0041), and in the popliteal vein (p = 0.003). The peak reflux flow was significantly higher in group II at the saphenofemoral junction (p < 0.0001), the saphenopopliteal junction (p = 0.0029), in the greater saphenous vein (p < 0.0001), in the common femoral vein (p = 0.006), in the superficial femoral vein (p = 0.0005), and in the popliteal vein (p = 0.0003). CONCLUSIONS Superficial venous insufficiency might play a major role in the development of advanced CVI. The peak reflux velocity and peak reflux volume improve discrimination power between early-stage and advanced CVI.


European Journal of Vascular and Endovascular Surgery | 2009

Presence of lower limb deep vein thrombosis and prognosis in patients with symptomatic pulmonary embolism: preliminary report.

Takashi Yamaki; Motohiro Nozaki; Hiroyuki Sakurai; Masaki Takeuchi; Kazutaka Soejima; Taro Kono

OBJECTIVES To investigate the presence of lower limb deep vein thrombosis (DVT) and prognosis in patients with symptomatic pulmonary embolism (PE). MATERIALS AND METHODS A total of 203 consecutive referral patients with PE were included. The distribution of DVT was evaluated with compression ultrasound (CUS), and all patients were then followed for 12 months for investigation of recurrence of venous thromboembolism (VTE) and fatal events as adverse outcome. RESULTS The mean age of the patients was 62.8 years, and 78 (38.4%) were males. DVT was found in 118 (58.1%) patients. Of these patients, 61 (30.0%) had proximal DVT. Multivariate analysis demonstrated that active cancer, inadequate anticoagulation, leg symptoms, male gender, presence of DVT, presence of proximal DVT, and previous DVT were independent risk factors for adverse outcome. A clinical risk score ranging from 0 to 10 points was generated on the basis of multivariate regression coefficients. Receiver operating characteristic curve analysis showed that an appropriate cut-off point for discriminating between the presence and the absence of an adverse event was 4. Using this category, 166 (81.8%) patients were classified as low risk and 37 (18.2%) as high risk for adverse outcome. The adverse event rates were 6.0% for the low-risk group and 59.5% for the high-risk group. CONCLUSIONS This study has confirmed the clinical significance of surveillance CUS in patients with a first episode of PE. Furthermore, a simple risk score on the basis of available variables can identify patients at risk of an adverse outcome in patients with PE.


Journal of Thrombosis and Haemostasis | 2007

High peak reflux velocity in the proximal deep veins is a strong predictor of advanced post-thrombotic sequelae.

Takashi Yamaki; Motohiro Nozaki; Hiroyuki Sakurai; Masaki Takeuchi; Kazutaka Soejima; Taro Kono

Summary.  Background: The presence of reflux in the femoral vein (FV) and popliteal vein (POPV) after acute deep vein thrombosis (DVT) is considered to contribute to the development of advanced post‐thrombotic syndrome (PTS). However, a quantification of reflux has yet to be determined. The purpose of study was to determine the indicative parameters reflecting the progression of PTS. Methods: Venous abnormalities were evaluated in 131 limbs out of 130 patients who completed a six‐year follow‐up after an acute DVT. Clinical manifestations were categorized according to the clinical, etiologic, anatomic, and pathophysiologic (CEAP) classification, and the patients were divided into two groups at a six‐year follow‐up point: group I, C0–3Es,As,d,p,Pr,o, early chronic venous insufficiency (CVI); group II, C4–6Es,As,d,p,Pr,o, advanced CVI. Venous segments were examined whether they were occluded or recanalized. The reflux parameters assessed were the diameter (cm), the reflux time (RT; s), the peak reflux velocity (PRV; cm s−1), and total refluxed volume, and these parameters were assessed especially in the FV and POPV at the two‐year (early phase) and subsequent six‐year (late phase) follow‐up points after DVT. Results: There were 98 limbs in group I and 33 in group II. The frequency of venous reflux was significantly higher in group II (<0.0001). In contrast, the proportion of occlusion did not differ between the groups (P = 0.138). The proportions of FV and POPV incompetence were significantly higher in group II (P < 0.0001 and P < 0.0001, respectively). In these veins, the RT did not improve the discrimination power between the two groups. In contrast, the PRV had significant discrimination power in these veins at both the two‐ and six‐year follow‐up points. In the superficial venous system, there were no significant differences in any of the determined parameters between the groups. In group II, 19 patients (58%), who had early symptoms of CVI at the two‐year follow‐up point, subsequently developed advanced symptoms of PTS. After calculating a suitable cutoff point using receiver operating characteristic curves analysis at the two‐year follow‐up point, multivariable analysis showed that a PRV of >25.4 cm s−1 in the POPV was the strongest independent predictor of advanced CVI [odds ratio (OR) 60.32; 95% confidence interval (95CI) 43.1–1238.97, P < 0.0001]. Similarly, in the FV, a PRV of >24.5 cm s−1 was found to be a strong predictor of advanced CVI (OR 25.77, 95CI 10.56–331.12, P < 0.0001). Conclusions: These findings suggest that the presence of a high PRV in the proximal deep veins is an independent predictor of advanced symptoms of PTS.


Dermatologic Surgery | 2000

Quantitative Assessment of Superficial Venous Insufficiency Using Duplex Ultrasound and Air Plethysmography

Takashi Yamaki; Motohiro Nozaki; Kenji Sasaki

Objective. The purpose of this study was to quantitatively evaluate venous reflux in limbs with isolated superficial venous insufficiency using color duplex ultrasound. In addition, air plethysmography (APG) was used to investigate possible correlations of duplex‐derived peak velocity, duration of reflux, and CEAP classification. Methods. One hundred and forty‐six legs in 109 patients with isolated superficial venous insufficiency refluxing throughout the length of the limb were selected for prospective study by duplex scan. Reflux was defined as duration of reflux ≥0.5 seconds. This study was conducted in a university hospital. Venous reflux was evaluated with the patients standing, by the duration of reflux, retrograde peak velocity, reflux volume at the saphenofemoral and saphenopopliteal junction as well as the greater saphenous vein in the thigh. Values obtained by APG were the venous volume (VV), venous filling index (VFI), ejection fraction (EF), and residual venous fraction (RVF). A significant difference was defined as P < .05. Three groups of limbs were analyzed: group A limbs with a retrograde peak velocity greater than 30 cm/second and a duration of reflux of less than 3 seconds; group B with a retrograde peak velocity ≥30 cm/second and a duration of more than 3 seconds; and group C with a retrograde peak velocity of less than 30 cm/second and a duration of reflux of more than 3 seconds. Results. Groups A and B contained 103 limbs, and 24 of these were in CEAP class 5 and 6. Group C contained 43 limbs, none of which were in class 5 or 6. APG demonstrated significant reflux in group A, and VFI was significantly higher compared to group B and group C (P = .0007 and P = .0064, respectively). A significant correlation was demonstrated between peak retrograde reflux velocity and VFI. Conclusions. Severe chronic venous insufficiency is found in limbs with high reflux velocity (greater than 30 cm/second) and the duration of reflux does not correlate with severe chronic insufficiency.


Dermatologic Surgery | 1998

Color duplex ultrasound in the assessment of primary venous leg ulceration.

Takashi Yamaki; Motohiro Nozaki; Kenji Sasaki

methods. To determine the extent and severelity of venous reflux, color duplex ultrasound was used in 370 limbs of 303 patients with primary varicose veins. The clinical findings were classified according to the CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical classification. results. Of 370 limbs, 32 showed previously healed ulcer (Class 5) and active ulcer (Class 6). Overall reflux in the superficial venous system was seen in 28 limbs (87.5%), and solitary superficial vein incompetence was detected in 13 (40.6%). Reflux was detected throughout the length of the superficial vein system, and the retrograde peak velocity was greater than 30 cm/second in these limbs. Reflux in the perforating veins was detected in 14 limbs (43.8%), but isolated perforating vein incompetence was seen in only one limb (3.1%). Deep vein incompetence was detected in 12 limbs (37.5%). Concomitant superficial and perforating vein reflux was evident in 4 limbs (12.5%) and 2 limbs (6.3%), respectively, but isolated deep vein incompetence was detected in only one limb (3.1%). The operations indicated were selective stripping of the long saphenous vein in the thigh, high ligation of the short saphenous vein, subfascial ligation of perforating veins, and compression sclerotherapy for varicose tributary veins. Healing of the ulcers was achieved within 1 month after surgery, and the postoperative color duplex scanning revealed correction of deep vein incompetence. conclusions. These data suggest that ablation of the superficial vein system and the perforating veins is an appropriate method for the management of patients with primary venous leg ulceration.


Annals of Plastic Surgery | 2007

Comparison study of intense pulsed light versus a long-pulse pulsed dye laser in the treatment of facial skin rejuvenation.

Taro Kono; William Frederick Groff; Hiroyuki Sakurai; Masaki Takeuchi; Takashi Yamaki; Kazutaka Soejima; Motohiro Nozaki

Currently, various nonablative skin resurfacing techniques are being used to rejuvenate facial skin, including lasers and intense pulsed light (IPL). There are few direct comparison studies between IPLs and lasers. The objective of our study is to compare the effectiveness of intense pulsed light versus a long-pulse pulsed dye laser (LPDL) in the treatment of facial skin rejuvenation. Ten Asian patients with Fitzpatrick skin types III–IV were enrolled in this study. One half of the face was treated with IPL (6 treatment sessions) and the other side was treated by LPDL (3 treatment sessions). An LPDL with a wavelength of 595 nm and spot size of 7 mm was used. Utilizing the compression method, lentigines were treated using a PDL with a fluence between 9–12 J/cm2 and a pulse duration of 1.5 ms. Wrinkles were treated with fluences between 10 to 12 J/cm2 and a pulse duration of 20 ms, using a pulse-stacking technique. An IPL with a type B handpiece was used. Lentigines and wrinkles were treated with fluences between 27 to 40 J/cm2 and a pulse duration of 20 ms. The improvement of lentigines was 62.3% and 81.1% for IPL and LPDL respectively. There was no significant difference between IPL and LPDL in wrinkle reduction. There was no scarring or pigmentary change seen with either device. Both IPL and LPDL are effective for facial skin rejuvenation in Asians, but LPDL treatment is significantly better than IPL treatment in the treatment of lentigines. The use of the compression technique may allow this LPDL to be used effectively for facial rejuvenation and with fewer treatment sessions, when compared with the IPL.


Journal of Cosmetic and Laser Therapy | 2009

Long‐pulsed neodymium:yttrium‐aluminum‐garnet laser treatment for hypertrophic port‐wine stains on the lips

Taro Kono; William Frederick Groff; Henry H. Chan; Hiroyuki Sakurai; Takashi Yamaki

Pulsed dye laser (PDL) treatment of hypertrophic port‐wine stains (PWSs) on the lips has demonstrated poor efficacy and a potential risk of dyspigmentation. PDL‐resistant hypertrophic PWS may require treatment with deeper penetrating lasers such as a 1064‐nm neodymium:yttrium‐aluminum‐garnet (Nd:YAG) laser. The objective of this clinical study was to evaluate the efficacy and safety of a Nd:YAG laser for the treatment of hypertrophic PWSs on the lips. Ten patients (four were male and six were female) with hypertrophic PWSs on the lips were recruited in this study. Eight patients showed good to excellent improvement without complications. In conclusion, the Nd:YAG laser is safe and effective for treating hypertrophic PWSs on the lips.

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Atsumori Hamahata

University of Texas Medical Branch

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