Kotaro Wakamatsu

Dr. Kotaro Wakamatsu

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
OTOshiro Takashi
Oshiro Takashi
KWKotaro Wakamatsu
Kotaro Wakamatsu
TNTaiki Nabekura
Taiki Nabekura
YMYuki Moriyama
Yuki Moriyama
NKNatsumi Kitahara
Natsumi Kitahara
Shinichi OkazumiShinichi Okazumi
Shinichi Okazumi
The number of laparoscopic sleeve gastrectomies (LSGs) performed in patients with obesity who are eligible for bariatric and metabolic surgery is currently much lower in Japan than in other countries. Considering the large number of potential patients with obesity and type 2 diabetes and the unique Japanese national health insurance system that guarantees fair healthcare delivery, there is room to increase the number of LSGs in Japan in the near future. However, strict health insurance regulations may limit access to mandatory devices needed to treat postoperative complications, such as staple line leakage, which can cause severe morbidity and even mortality. Therefore, understanding the pathogenesis and treatment options for this complication is crucial. This article examined the current situation in Japan and its impact on staple line leakage management, including the role of endoscopic treatment in reducing reoperation. The authors suggest increasing education and collaboration between healthcare professionals to optimize management and improve patient outcomes.

27 December 2024 in Journal of Clinical Medicine
Verified
Journal Article
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KWKotaro Wakamatsu
Kotaro Wakamatsu
AMAtsushi Maruyama
Atsushi Maruyama
Shinichi OkazumiShinichi Okazumi
Shinichi Okazumi
Background: The dysregulation of microRNAs (miRNAs) has been detected in patients with gastric cancer (GC), which inspired the use of miRNAs as a novel biomarker for GC. In this study, we investigated the previously reported miRNA dysfunction in cancer tissues as a potential plasma biomarker for GC using quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Methods: The published miRNA abnormalities were searched in the microRNA Cancer Association Database. Plasma samples were collected from patients with GC (n = 26) and controls (n = 17). The sensitivity and specificity of polyadenylation RT-PCR (PA-RT) and stem-loop RT-PCR (SL-RT) were compared. Statistical comparisons between patients with GC and controls were performed to identify miRNA biomarkers, and correlation analyses between the threshold cycle (Ct) values of miRNAs and various blood biochemical parameters were performed to elucidate the confounding factors. Results: mir-17, mir-21, mir-31, mir-99b, mir-222, and U6 were selected. PA-RT showed greater sensitivity and lower specificity than SL-RT (PA-RT vs. SL-RT, mean Ct: 19.6 vs. 29.2; coefficient of variation: 0.42 vs. 0.10). Adopting SL-RT owing to its higher specificity, only mir-222 was significantly upregulated in patients with GC (GC vs. control, miRNA expression: 15.4 vs. 5.27, p = 0.0098). Regarding the correlation between blood biochemical parameters and cells with miRNA expression, mir-31 and mir-99b were correlated with blood urea nitrogen, mir-17, mir-21, and mir-99b were negatively correlated with platelets, and mir-21 was correlated with neutrophils. No obvious correlations were noted between mir-222 expression and blood parameters. Receiver operating characteristic (ROC) curve analysis indicated that mir-222 identified GC patients with a maximum area under the curve (0.73, 95% confidence interval 0.57–0.89). Conclusions: Plasma mir-222 was confirmed to be dysregulated in patients with GC, irrespective of blood biochemical parameters.

Verified
Journal Article
Open access
PDF file
TNTaiki Nabekura
Taiki Nabekura
OTOshiro Takashi
Oshiro Takashi
KWKotaro Wakamatsu
Kotaro Wakamatsu
NKNatsumi Kitahara
Natsumi Kitahara
YMYuki Moriyama
Yuki Moriyama
Shinichi OkazumiShinichi Okazumi
Shinichi Okazumi
Piriform fossa and/or esophageal injuries caused by calibration tubes are relatively rare and remain unelucidated. Herein, we report the case of a 36-year-old woman with morbid obesity, sleep apnea, and menstrual abnormalities who was scheduled to undergo laparoscopic sleeve gastrectomy (LSG). We inserted a 36-Fr Nelaton catheter made of natural rubber as a calibration tube during the surgery. However, excessive resistance was observed. We confirmed a submucosal layer detachment approximately 5 cm from the left piriform fossa to the esophagus using intraoperative endoscopy. Additionally, LSG was performed using an endoscope as the guiding calibration tube. We inserted a nasogastric tube under endoscopy with a guidewire before completing the surgery, hoping for a guiding effect on the saliva flow. After 17 months, the patient had successfully lost weight postoperatively without complaints of neck pain or discomfort during swallowing. Therefore, in cases where the damage is limited to the submucosal layer, as in this case, conservative therapy should be considered; this is similar to the concept of endoscopic submucosal dissection not requiring suture closure. This case highlights the risk of iatrogenic injuries to the piriform fossa and/or esophagus during LSG and the importance of careful calibration tube insertion to prevent them.

1 January 2025 in Surgical Case Reports
Verified
Journal Article
Open access
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TNTaiki Nabekura
Taiki Nabekura
OTOshiro Takashi
Oshiro Takashi
KWKotaro Wakamatsu
Kotaro Wakamatsu
INTRODUCTION: Laparoscopic sleeve gastrectomy is the most common metabolic bariatric surgery performed in Japan. Nevertheless, concerns persist regarding its long-term efficacy, which is considered inferior to that of procedures involving gastrointestinal bypass. In response to these concerns, a modified approach known as the “sleeve plus procedure” has been introduced and is now covered by insurance for patients with severe obesity and type 2 diabetes mellitus (T2DM). We successfully performed proximal jejunal bypass with sleeve gastrectomy (PJB-SG), a variant of this approach, marking the first documented case of its kind in Japan. This report presents the clinical outcomes of this procedure along with a review of the relevant literature.CASE PRESENTATION: A 50-year-old female patient with a body mass index of 46.9 kg/m2 presented with obstructive sleep apnea and T2DM. The patient exhibited resistance to pharmacological treatment, including glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors. Fifteen months after the initial consultation, she opted for PJB-SG. The operation lasted 207 min, with 18 mL of blood loss. At 252 days postoperatively, the patient had achieved a total weight loss of 18.0% and a hemoglobin A1c level of 6.0% while continuing a minimal dose of SGLT2 inhibitors. No adverse events related to the bypass procedure, such as diarrhea or liver dysfunction, were observed.CONCLUSIONS: To our knowledge, this is the first reported case of PJB-SG conducted in Japan. This procedure may represent a promising alternative for patients with severe obesity and T2DM in Japan.

15 February 2023 in Asian Journal of Surgery
Verified
Journal Article
Open access
KWKotaro Wakamatsu
Kotaro Wakamatsu
OTOshiro Takashi
Oshiro Takashi

19 April 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
TNTaiki Nabekura
Taiki Nabekura
OTOshiro Takashi
Oshiro Takashi
KWKotaro Wakamatsu
Kotaro Wakamatsu
NKNatsumi Kitahara
Natsumi Kitahara
YMYuki Moriyama
Yuki Moriyama
Shinichi OkazumiShinichi Okazumi
Shinichi Okazumi
Piriform fossa and/or esophageal injuries caused by calibration tubes are relatively rare and re-main unelucidated. Herein, we report the case of a 36-year-old woman with morbid obesity, sleep apnea, and menstrual abnormalities who was scheduled to undergo laparoscopic sleeve gastrectomy (LSG). We inserted a 36-Fr Nelaton catheter made of natural rubber as a calibration tube during the surgery. However, excessive resistance was observed. We confirmed a submuco-sal layer detachment of approximately 5 cm from the left piriform fossa to the esophagus using intraoperative endoscopy. Additionally, LSG was performed using an endoscope as the guiding calibration tube. We inserted a nasogastric tube under endoscopy with a guidewire before com-pleting the surgery, hoping for a guiding effect on saliva flow. After 17 months, the patient suc-cessfully lost weight postoperatively without complaints of neck pain or discomfort during swallowing. Therefore, if the damage is limited to the submucosal layer, as in this case, conserva-tive therapy should be considered, which is similar to the concept of not requiring suture closure in endoscopic submucosal dissection. This case highlights the risk of iatrogenic injuries to the pi-riform fossa and/or esophagus during LSG and the importance of careful calibration tube inser-tion to prevent them.