笹沼 英紀

Background: Osteopenia is a well-known risk factor for survival in patients with hepatocellular carcinoma; however, it is unclear whether osteopenia can apply to both genders and how osteopenia is associated with cancer progression. The aim of this study was to elucidate whether osteopenia predicts reduced survival in regression models in both genders and whether osteopenia is associated with the pathological factors associated with reduced survival. Methods: This study included 188 consecutive patients who underwent hepatectomy. Bone mineral density was assessed using computed tomography (CT) scan images taken within 3 months before surgery. Non-contrast CT scan images at the level of the 11th thoracic vertebra were used. The cutoff value of osteopenia was calculated using a threshold value of 160 Hounsfield units. Overall survival (OS) curves and recurrence-free survival (RFS) were constructed using the Kaplan–Meier method, as was a log-rank test for survival. The hazard ratio and 95% confidence interval for overall survival were calculated using Cox’s proportional hazard model. Results: In the regression analysis, age predicted bone mineral density. The association in females was greater than that in males. The OS and RFS of osteopenia patients were shorter than those for non-osteopenia patients. According to univariate and multivariate analyses, osteopenia was an independent risk factor for OS and RFS. The sole pathological factor associated with osteopenia was microvascular portal vein invasion. Conclusion: Models suggest that osteopenia may predict decreased OS and RFS in patients undergoing resection of hepatocellular carcinoma due to the mechanisms mediated via microvascular portal vein invasion.

Abstract Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.

Abstract It is important to assess the prognosis and intervene before and after surgery in patients with hepatocellular carcinoma. This study aims to elucidate the association of outcomes and residual liver function after hepatectomy. A total of 176 patients who underwent the initial resection for hepatocellular carcinoma between January 2011 and March 2021 at Jichi Medical University were included. Hepatic clearance of the remnant liver was measured using 99mTc-galactosyl serum albumin scintigraphy. The log-rank test was used to analyze survival using the Kaplan–Meier method. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival were calculated using Cox’s proportional hazard model. In multivariate analysis, microvascular invasion, intraoperative blood loss, and hepatic clearance of the remnant liver were independently associated with overall survival. Hepatic clearance of the remnant liver was independently associated with recurrence free survival. This is the first report to show that lower residual liver function is associated with shorter survival in patients with hepatocellular carcinoma undergoing hepatectomy. Preoperative determination of remnant liver function may allow assessment of prognosis in patients planned to undergo resection of hepatocellular carcinoma. Preservation of liver functional reserve may be crucial for improved long-term outcomes after hepatectomy.

【背景】2019年3月から腹部開放創用ABTHERAドレッシングキットが本邦で使用可能となった。本邦にABTHERAが導入されてからのopen abdominal management(以下,OAM)の実態や予後に関連する因子は明らかになっていない。【目的】本研究の目的は,連続35例のOAMの特徴,治療成績を明らかにし,短期予後にかかわる因子を検討することである。【対象および方法】2019年6月から2021年6月までのABTHERAを用いた連続35例を外傷・非外傷群,生存・死亡群に分け各因子を比較した。【結果】非外傷群は有意に高齢で,死亡率は外傷群16.7%,非外傷群43.5%,筋膜閉鎖率は91.4%であった。APACHE IIスコアは平均19.7,非外傷群・死亡群で有意に高く,予後因子であった。【結論】APACHE IIスコアは非外傷群,死亡群で有意に高く,短期予後予測に有用な可能性がある。(著者抄録)

BACKGROUND: Acute superior mesenteric artery (SMA) occlusion is an uncommon condition associated with high mortality. If extensive bowel resection is performed for patients with acute SMA occlusion and the patient survives, long-term total parenteral nutrition (TPN) may be needed due to short bowel syndrome. This study examined factors associated with the need for long-term TPN after the treatment of acute SMA occlusion. METHODS: We retrospectively analyzed 78 patients with acute SMA occlusion. Patients were abstracted from a Japanese database from institutions with at least 10 patients with acute SMA occlusive disease from January 2015 through December 2020 RESULTS: Among the initial cohort there were 41/78 survivors. Of these, 14/41 (34%) required permanent TPN who were compared with those who did not require long-term TPN (27/41, 66%). Compared to patients in the non-TPN group, those in the TPN group had significantly shorter remaining small intestine (90.7 cm vs. 218 cm, P<0.01), more patients with time from onset to intervention >6 hours (P=0.02), pneumatosis intestinalis on enhanced computed tomography scan (P=0.04), ascites (Odds Ratio 11.6, P<0.01), and a positive smaller superior mesenteric vein sign (P= 0.03). These were considered significant risk factors for needing long-term TPN. Age, gender, underlying disease, presence of peritoneal sign, presence of shock requiring vasopressors, site of obstruction (proximal vs. distal), and initial treatment (surgery vs. interventional radiology vs. thrombolytic therapy) were not significantly different between the two groups. Long-term TPN was significantly associated with longer hospital stay (52 vs. 35 days, P=0.04). Multivariate analysis identified the presence of ascites as an independent risk factor for needing long-term TPN. CONCLUSION: The need for permanent TPN after treatment of acute SMA occlusion is significantly associated with longer hospital stay, longer time to intervention, and characteristic imaging findings (pneumatosis intestinalis, ascites, Smaller SMV sign). Ascites is an independent risk factor. LEVEL OF EVIDENCE: III.

PURPOSE: The safety of acoustic radiation force impulse (ARFI) elastography, which applies higher acoustic power with a longer pulse duration (PD) than conventional diagnostic ultrasound, is yet to be verified. We assessed the ARFI-induced lung injury risk and its relationship with peak rarefactional pressure amplitude (PRPA) and mechanical index (MI). METHODS: Eighteen and two rabbits were included in the ARFI (0.3-ms push pulses) and sham groups, respectively. A 5.2-MHz linear probe was applied to the subcostal area and aimed at both lungs through the liver for 30 ARFI emissions. The derated PRPA varied among the six ARFI groups-0.80 MPa, 1.13 MPa, 1.33 MPa, 1.70 MPa, 1.91 MPa, and 2.00 MPa, respectively. RESULTS: The occurrence of lung hemorrhage and the mean lesion area among all samples in the seven groups were 0/6, 0/6, 1/6 (1.7 mm2), 4/6 (8.0 mm2), 4/6 (11.2 mm2), 5/6 (23.8 mm2), and 0/4 (sham), respectively. Logistic regression analysis showed that derated PRPA was significantly associated with lung injury occurrence (odds ratio: 207, p < 0.01), with the threshold estimated to be 1.1 MPa (MI, 0.5). Spearman's rank correlation showed a positive correlation between derated PRPA and lesion area (r = 0.671, p < 0.01). CONCLUSION: This study demonstrated that the occurrence and severity of ARFI-induced lung hemorrhage increased with a rise in PRPA under clinical conditions in rabbits. This indicates a potential risk of lung injury due to ARFI elastography, especially when ARFI is unintentionally directed to the lungs during liver, heart, or breast examinations.

Background: The prognostic importance of osteopenia in patients with intrahepatic cholangiocarcinoma (ICC) undergoing hepatectomy is unclear. The aim of this study was to evaluate the impact of osteopenia on survival in patients with ICC. Methods: A total of 71 patients who underwent hepatectomy at Jichi Medical University between July 2008 and June 2022 were included in this study. Non-contrast computed tomography scan images at the eleventh thoracic vertebra were used to assess bone mineral density. The cutoff value was calculated using a threshold value of 160 Hounsfield units. Overall survival curves were made using the Kaplan–Meier method and the log-rank test was used to evaluate survival. The hazard ratio (HR) and 95% confidence interval (CI) for overall survival were calculated using Cox’s proportional hazard model. Results: In multivariable analysis, osteopenia (HR 3.66, 95%CI 1.16–14.1, p = 0.0258) and the platelet–lymphocyte ratio (HR 6.26, 95%CI 2.27–15.9, p = 0.0008) were significant independent factors associated with overall survival. There were no significant independent prognostic factors for recurrence-free survival. Conclusions: Preoperative osteopenia is significantly associated with postoperative survival in patients with ICC undergoing hepatectomy.

BACKGROUND: Estimation of the functional reserve of the remnant liver is important to reduce morbidity and mortality. AIM: To estimate the functional reserve of the remnant liver in patients with hepatocellular carcinoma (HCC). METHODS: We reviewed the medical records of 199 patients who underwent resection of HCC. Hepatic clearance of the remnant liver was calculated using fusion images of 99mTc-labelled galactosyl-human serum albumin liver scintigraphy and computed tomography. Posthepatectomy liver failure (PHLF) was classified according to the International Study Group of Liver Surgery. Complications was classified according to Clavien-Dindo classification. We analyzed by the risk factors for PHLF, morbidity and mortality with multivariate analysis. RESULTS: Twenty-seven (30%) patients had major complications and 23 (12%) developed PHLF. The incidence of major complications increased with increasing albumin-bilirubin (ALBI) grade. The area under the curve values for hepatic clearance of the remnant liver, liver to heart-plus-liver radioactivity at 15 min (LHL15), and ALBI score predicting PHLF were 0.868, 0.629, and 0.655, respectively. The area under the curve for hepatic clearance of the remnant liver, LHL15, and ALBI score predicting major complications were 0.758, 0.594, and 0.647, respectively. The risk factors for PHLF and major complications were hepatic clearance of the remnant liver and intraoperative bleeding. CONCLUSION: The measurement of hepatic clearance may predict PHLF and major complications for patients undergoing resection of HCC.

BACKGROUND: Osteopenia is defined as low bone mineral density (BMD) and has been shown to be associated with outcomes of patients with various cancers. The association between osteopenia and perihilar cholangiocarcinoma is unknown. The aim of this study was to evaluate osteopenia as a prognostic factor in patients with perihilar cholangiocarcinoma. METHODS: A total of 58 patients who underwent surgery for perihilar cholangiocarcinoma were retrospectively analyzed. The BMD at the 11th thoracic vertebra was measured using computed tomography scan within one month of surgery. Patients with a BMD &lt; 160 HU were considered to have osteopenia and b BMD ≥ 160 did not have osteopenia. The log-rank test was performed for survival using the Kaplan-Meier method. After adjusting for confounding factors, overall survival was assessed by Cox's proportional-hazards model. RESULTS: The osteopenia group had 27 (47%) more females than the non-osteopenia group (p = 0.036). Median survival in the osteopenia group was 37 months and in the non-osteopenia group was 61 months (p = 0.034). In multivariable analysis, osteopenia was a significant independent risk factor associated with overall survival in patients with perihilar cholangiocarcinoma (hazard ratio 3.54, 95% confidence interval 1.09-11.54, p = 0.036), along with primary tumor stage. CONCLUSIONS: Osteopenia is associated with significantly shorter survival in patients with perihilar cholangiocarcinoma.

BACKGROUND/PURPOSE: Metal stents (MS) are recommended for preoperative biliary drainage (PBD) in patients with periampullary cancer, but whether MS are superior in terms of re-intervention and direct cost is debatable. This study aimed to compare the effects of MS and PS on the outcomes of patients with periampullary cancer. METHODS: For this random-effects meta-analysis, electronic databases were screened for randomized controlled trials (RCTs) published until January 2022. Subgroup analyses were performed basis on the center type and presence of NAC. RESULTS: In this meta-analysis, seven RCTs (440 participants) were included. MS reduced re-interventions (risk ratio [RR] = 0.42, 95% confidence interval [CI] = 0.25-0.72) and direct costs (mean difference = -474 USD, 95% CI = -656 to -292). PBD-related complications (RR = 0.74, 95% CI = 0.32-1.71) and postoperative complications (RR = 0.73, 95% CI = 0.45-1.17) did not differ between MS and PS. Compared PS, MS reduced postoperative complications in high-volume centers (RR = 0.64, 95% CI = 0.49-0.84) and PBD-related complications in patients receiving NAC (RR = 0.29, 95% CI = 0.08-1.08). CONCLUSIONS: Metal stents likely reduces re-interventions and direct costs. Further studies are needed to confirm the effects of MS on the outcomes.

INTRODUCTION AND IMPORTANCE: Intussusception is invagination of the bowel and is rare in adults, representing only 5% of all cases of intussusception. Duodenal intussusception is also very rare. To the best of our knowledge, there is only one previous report of a malignant tumor in the fourth portion of the duodenum as the lead point of intussusception (Vaibhav et al., 2021 [1]). This reports a duodenal-duodenal intussusception caused by a malignant tumor in the third portion of the duodenum. CASE PRESENTATION: A 36-year-old woman with abdominal pain was diagnosed with duodenal intussusception by abdominal ultrasonography and computed tomography scan. Double balloon endoscopy showed that the intussusception had spontaneously reduced, and a tumor was found in the third portion of the duodenum. Open resection was performed because of the tumor location. Pathologic examination revealed adenocarcinoma with an adenoma of the duodenum. The patient had no evidence of recurrence for 4 years after resection. CLINICAL DISCUSSION: This patient had a primary duodenal malignancy and presented with intussusception, Duodenal intussusception is a rare condition requiring prompt intervention, usually requiring surgery. In this patient, since endoscopic resection was difficult, partial resection of duodenum was performed by open surgery assisted by double balloon enteroscopy. The pathological diagnosis of the resected specimen was primary duodenal malignancy. CONCLUSION: This is a report of adult duodenal intussusception caused by a primary duodenal malignancy. This rare condition posed an intriguing challenge for the optimal operative approach.

Acoustic radiation force impulse (ARFI) imaging and shear wave elastography use a "push pulse." The push pulse, which is referenced as an ARFI in this study, has a longer duration than that of conventional diagnostic pulses (several microseconds). Therefore, there are concerns regarding thermal safety in vivo. However, few in vivo studies have been conducted using living animals. In this study, to suggest a concept for deciding an ARFI output and cooling time while considering thermal safety, the liver (with and without an ultrasound contrast agent) and femur bone surface of living rabbits were exposed to an ARFI, and the maximum temperature rise, temperature rise for 5-min duration, and cooling time were measured via a thermocouple. While testing within the regulation limits of diagnostic ultrasound outputs, a maximum temperature rise on the femur bone surface exceeded the allowable temperature rise (1.5°C) in the British Medical Ultrasound Society (BMUS) statement. However, using the linear relationships between the pulse intensity integral (PII) of a single pulse and the above three temperature parameters, PII may be determined so that the maximum temperature rise is within the allowable temperature rise in the BMUS statement. The cooling time can be estimated from the PII.

BACKGROUND/PURPOSE: Previous systematic reviews have shown that radical antegrade modular pancreatosplenectomy (RAMPS) had favorable outcomes including prognosis. However, recent large studies have shown opposite results, thus necessitating clarification of RAMPS efficacy. We aimed to update existing evidence on the clinical outcomes of RAMPS for left-sided pancreatic cancer by comparing them to those of the conventional approach. METHODS: Electronic databases and registries were searched until August 2021 to perform random-effect meta-analysis. Methodological quality was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. The protocol was registered at protocols.io (https://doi.org/10.17504/protocols.io.bxhfpj3n). RESULTS: Thirteen cohort studies (1641 patients) and four ongoing randomized controlled trials (RCTs) were identified. RAMPS increased disease-free survival (hazard ratio [HR] 0.62, 95% confidence interval [CI] = 0.42-0.91), but it had little effect on overall survival (HR 0.92, 95% CI = 0.79-1.09) and recurrence-free survival (HR 0.72, 95% CI = 0.37-1.38) with low certainty of evidence. CONCLUSION: The meta-analysis of recent studies suggests that RAMPS may have little effect on clinical outcomes. These findings highlight the necessity of further studies, including RCTs to determine the efficacy and subsequent indication of RAMPS in clinical cases.

Acoustic radiation force impulse (ARFI) elastography has been used to diagnose acute pancreatitis (AP). The present study aimed to assess the effectiveness of ARFI elastography in the diagnosis of AP. Studies examining the efficacy of ARFI elastography in AP were selected by searching MEDLINE, EMBASE, CENTRAL, ICTRP, and ClinicalTrial.gov. until September 2021. Meta-analyses were performed using random effects models. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the certainty of the evidence. Eight case-control studies (994 patients) were included in the meta-analysis. The ARFI-Virtual Touch Quantification value (or ARFI shear wave propagation velocity) of the AP patient group was 0.83 m/s higher (95% confidence interval [CI]: 0.36-1.3) than that in the control group (95% CI: 1.0-1.28). The sensitivity and specificity of ARFI elastography for diagnosing AP were 98.3% (95% CI: 92.6-96.6%) and 95.5% (95% CI: 87.5-98.5%), respectively. The results showed that physicians could use ARFI elastography to accurately diagnose patients with AP. Additional well-designed studies are necessary to validate the efficacy of ARFI elastography in patients with AP.

BACKGROUND: Sarcopenia, as assessed by body composition, can affect morbidity and survival in several gastrointestinal cancer. However, the impact of sarcopenia, referring to both quantity and quality of skeletal muscle, in biliary tract cancer (BTC) is debatable. We aimed to investigate the impact of sarcopenia on morbidity and mortality in patients with BTC. METHODS: Electronic databases and trial registries were searched through July 2021 to perform random-effects meta-analyses. Study selection, data abstraction and quality assessment were independently performed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. RESULTS: Twenty-nine studies (4443 patients) were included; 28 used computed tomography and one used dual-energy X-ray absorptiometry to assess body composition. Eighteen studies reported the impact of pre-operative sarcopenia on postoperative outcomes; namely, sarcopenia increased postoperative complications (risk ratio = 1.23, 95% confidence interval [CI] = 1.07 to 1.41; I2 = 2%), and decreased recurrence-free survival (hazard ratio [HR] = 2.20, 95% CI = 1.75 to 2.75; I2 = 0%) in multivariable analyses. Low muscle quantity (HR = 2.26, 95% CI = 1.75 to 2.92; I2 = 66%) and quality (HR = 1.75, 95% CI = 1.33 to 2.29; I2 = 50%) decreased overall survival in multivariable analyses. The certainty of the evidence was low because of heterogeneity and imprecision. CONCLUSIONS: In sarcopenia, low muscle quantity and quality by body composition conferred an independent risk of morbidity and mortality in patients with BTC. Further studies are needed to confirm these findings and mitigate risk.

症例は57歳男性.検診で膵体部の嚢胞性病変が指摘され,当院を紹介された.造影CTでは膵体部に17mm大の中心部に嚢胞成分を伴う充実性腫瘤が認められた.3年後の造影CTでは,嚢胞成分を伴いながら23mm大に腫瘍径が増大し,MRIでは中心部の嚢胞成分はT1WI,T2WIともに高信号を示し,辺縁は拡散低下を伴う充実成分として観察された.超音波内視鏡検査でも同様に,中心に嚢胞成分を伴う充実性腫瘤として観察された.膵体尾部切除が施行され,病理学的にmixed acinar-neuroendocrine carcinoma(MAcNEC)と診断された.腫瘍中央の嚢胞成分は壊死によるものが疑われ,その周囲にsynaptophysin陽性の領域が,更にその周囲にBCL10,trypsin陽性の領域が分かれて確認された.本症例はMAcNECの発生様式を考察する上で示唆に富む症例であり,文献的考察を加え報告する.(著者抄録)

大腸癌の血行性転移には、肝転移、肺転移、その他(脳、骨、副腎など)がある。肝転移と肺転移は、治癒切除により予後改善効果が報告されており、多発転移であっても他臓器に転移を認めない場合は、治癒切除可能かどうかを注意深く見極めることが重要である。また近年の化学療法の進歩により、初診時には切除不能な肝転移であっても、化学療法後の縮小により切除可能となる場合がある。切除後の予後ははじめから切除可能な肝転移のそれとほぼ同等とされ、このconversion therapyは多発肝転移を有する進行大腸癌に対する治療戦略のひとつとして確立されている。肺転移についても、一定の条件を満たす症例では切除により予後の改善が報告されており、近年の胸腔鏡手術の技術や器機の進歩により、両葉や多発病変の切除も可能となっている。ただし肺転移切除の治療成績については大規模研究の報告が少なく、ほとんどが後ろ向き研究であることから、今後の研究結果の集積が待たれる。(著者抄録)

症例は48歳の男性で,約1ヵ月前に左手外傷に対して鼠径部より採皮,植皮術を施行され,退院後より腹部違和感を自覚していた.腹部症状が増悪し意識障害も出現したため前医を受診し,造影CTで広範な門脈血栓症を認め,入院となった.翌日,下部消化管出血を認め,当院転院となった.転院時造影CTで上腸間膜静脈血栓症と診断された.小腸壊死は明らかでなく,抗凝固療法を開始し,約40日の経過で血栓はほぼ消失した.経口摂取開始後に嘔吐が出現したため,小腸造影および小腸3D-CTを撮影したところ上部空腸の器質的狭窄を認めた.転院後第59病日に小腸部分切除術を施行した.病理学的には血栓形成を伴う虚血性腸炎の診断であった.術後20日目に退院し,現在も再発は認めていない.本症例では,3D-CTが遅発性小腸狭窄の範囲の推定と切除範囲の決定に有用であった.(著者抄録)

Long-acting somatostatin analogs, including lanreotide slow release (LAN-SR) and octreotide long-acting release (OCT-LAR), can improve hypoglycemia in insulinoma. LAN-SR may be more beneficial in some patients with insulinoma than OCT-LAR.

胆膵領域に発生する腫瘍は、しばしば画像診断に難渋する。画像診断精度を向上させるためには、術前画像で異常所見を拾い上げる所見のための根拠を病理組織学的に検証していくことが重要である。当施設では、詳細な術前画像と病理像の対比のために、臨床医と病理医が協力して「検体造影検査」に加え「術後検体超音波検査」を行っている。とくに、「術後検体超音波検査」は、簡便で、病理像・画像対比に適した病理組織標本を作ることができ、画像所見へのフィードバックや診療科横断的なコミュニケーションツールとしても有意義な検査である。(著者抄録)

症例は37歳,女性.25歳で偶発的に膵体尾部に嚢胞性病変を指摘され,精査目的に当院消化器内科に紹介された.腹部造影CTとMRI検査では膵尾部に約5cmの嚢胞性腫瘤を認め膵粘液性嚢胞腫瘍(mucinous cystic neoplasm:MCN)が疑われたが,経過観察の方針となった.32歳時の第2子妊娠を契機に経過観察が一時中断となり,5年後の37歳に再診した.嚢胞性腫瘤は多房化し,大きさ6cmへの増大を認め,血清CA19-9の上昇を伴ったことから手術目的に消化器外科紹介となった.腹腔鏡下膵体尾部脾摘術を施行し,術後経過は良好で術後11日目に退院した.病理組織像では卵巣様間質を認め,微小浸潤を伴った膵粘液性嚢胞腺癌の診断であった.MCNの自然史を解明するには長期経過観察例の集積が必要である.(著者抄録)

PURPOSE: We previously reported that acoustic radiation force impulse (ARFI) with concomitant administration of perfluorobutane as an ultrasound contrast agent (UCA)-induced arrhythmias at a mechanical index (MI) of 1.8 or 4.0 in a rabbit model. The present study identified the location of arrhythmias with a MI < 1.8 using a new system that can transmit ARFI with B-mode imaging. METHODS: Under general anesthesia, six male Japanese white rabbits were placed in a supine position. Using this system, we targeted ARFI to the exact site of the heart. ARFI exposure with MI 0.9-1.2 was performed to the right or left ventricle of the heart 2 min after UCA injection. RESULTS: ARFI with a MI lower than previously reported to rabbit heart evoked extrasystolic waves with single UCA infusion. Arrhythmias were not observed using ARFI without UCA. Extrasystolic waves were observed significantly more frequently in the right ventricle group than in the left ventricle group, with arrhythmias showing reversed shapes. No fatal arrhythmias were observed. CONCLUSION: ARFI applied to simulate clinical conditions in rabbit heart evoked extrasystolic waves with single UCA infusion. The right ventricle group was significantly more sensitive to ARFI exposure, resulting in arrhythmias, than the left ventricle group. The shapes of PVCs that occurred in the right ventricle group and the left ventricle group were reversed. Ultrasound practitioners who use ARFI should be aware of this adverse reaction, even if the MI is below the previously determined value of 1.9.

症例は37歳,女性.25歳で偶発的に膵体尾部に嚢胞性病変を指摘され,精査目的に当院消化器内科に紹介された.腹部造影CTとMRI検査では膵尾部に約5cmの嚢胞性腫瘤を認め膵粘液性嚢胞腫瘍(mucinous cystic neoplasm:MCN)が疑われたが,経過観察の方針となった.32歳時の第2子妊娠を契機に経過観察が一時中断となり,5年後の37歳に再診した.嚢胞性腫瘤は多房化し,大きさ6cmへの増大を認め,血清CA19-9の上昇を伴ったことから手術目的に消化器外科紹介となった.腹腔鏡下膵体尾部脾摘術を施行し,術後経過は良好で術後11日目に退院した.病理組織像では卵巣様間質を認め,微小浸潤を伴った膵粘液性嚢胞腺癌の診断であった.MCNの自然史を解明するには長期経過観察例の集積が必要である.(著者抄録)