Long-Term Outcomes of a Japanese Prospective Multicenter Registry Using a Heparin-Bonded Expanded Polytetrafluoroethylene Graft for Above-the-Knee Femoropopliteal Bypasses

BACKGROUND

Despite the widespread use of PROPATEN®, a bioactive heparin-bonded expanded polytetrafluoroethylene graft, in bypass surgery, there are only a few reports of long-term results. We evaluated the long-term results of PROPATEN®use for above-knee femoropopliteal bypass (AKFPB).Methods and Results: After PROPATEN®-based AKFPB, patients were prospectively registered at 20 Japanese institutions between July 2014 and October 2017 to evaluate long-term results. During the median follow-up of 76 months (interquartile range 36-88 months) for 120 limbs (in 113 patients; mean [±SD] age 72.7±8.1 years; 66.7% male; ankle-brachial index [ABI] 0.45±0.27; lesion length 26.2±5.7 cm; chronic limb-threatening ischemia in 45 limbs), there were 8 major amputations; however, clinical improvement was sustained (mean [±SD] ABI 0.87±0.23) and the Rutherford classification grade improved in 105 (87.5%) limbs at the latest follow-up. At 8 years, the primary patency, freedom from target-lesion revascularization, secondary patency, survival, and amputation-free survival, as estimated by the Kaplan-Meier method, were 66.3±4.8%, 71.5±4.4%, 86.5±3.4%, 53.1±5.0%, and 47.4±5.3%, respectively.

CONCLUSIONS

This multicenter prospective registry-based analysis showed sustained excellent clinical improvement and secondary patency for up to 8 years following PROPATEN®-based AKFPB. PROPATEN®constitutes a durable and good revascularization option for complex superficial femoral artery lesions, especially when endovascular treatment is inappropriate or an adequate venous conduit is unavailable.

Impact of wound management strategies after revascularization for chronic limb-threatening ischemia

OBJECTIVE

There is no established consensus or guidelines for wound management after revascularization for patients with chronic limb-threatening ischemia (CLTI) without severe infection. This study is designed to evaluate the clinical effect of the wound management strategy on toe wounds after revascularization for CLTI.

METHODS

This retrospective cohort study was performed at eight institutions affiliated with Keio University School of Medicine in Japan and included 261 patients who underwent revascularization for CLTI between April 2019 and July 2021. We identified 132 patients with toe wounds from the database who had restored in-line blood flow to the foot. Patients were divided into two groups by the timing of toe resection after revascularization, which dictated the wound management policy. Group A (62 patients) underwent early toe amputation for suspected osteomyelitis, whereas group B (70 patients) underwent watchful waiting. The primary outcome was wound healing after revascularization; the secondary outcome was major amputation. We compared outcomes between groups A and B after propensity score matching.

RESULTS

Using propensity score matching, each patient in group A (33 patients) was matched with a patient in group B (33 patients). Wound healing in matched group A was significantly better than that in matched group B (respectively: 1-year wound healing rate: 90.0% vs 68.2%, P < .001; median wound healing time: 65 days vs 258 days, P < .01). Although five major amputations were necessary in matched group B, none were required in matched group A (P = .05). The high rate of major amputations in group B was attributed to the sudden exacerbation of infection. Limb salvage rate in matched group A exceeded matched group B (100.0% vs 90.5%: 1-year limb salvage rate, P = .02).

CONCLUSIONS

Early toe amputation for highly suspected osteomyelitis in patients with CLTI with toe wounds may expedite wound healing compared with watchful waiting, potentially avoiding unnecessary major amputation. Considering the wound management strategy is crucial when evaluating wound healing outcomes in patients with CLTI with revascularization.

Noninvasive graft monitoring using donor-derived cell-free DNA in Japanese liver transplantation

AIM

To evaluate the use of donor-derived cell-free DNA (dd-cfDNA) in diagnosing graft injuries in Japanese liver transplantation (LTx), including family-related living donors.

METHODS

A total of 321 samples from 10 newly operated LTx recipients were collected to monitor the early dynamics of dd-cfDNA levels after LTx. Fifty-five samples from 55 recipients were collected during protocol biopsies (PB), whereas 36 samples from 27 recipients were collected during event biopsies, consisting of 11 biopsy-proven acute rejection (AR), 20 acute dysfunctions without rejection (ADWR), and 5 chronic rejections. The levels of dd-cfDNA were quantified using a next-generation sequencer based on single nucleotide polymorphisms.

RESULTS

The dd-cfDNA levels were elevated significantly after LTx, followed by a rapid decline to the baseline in patients without graft injury within 30 days post-LTx. The dd-cfDNA levels were significantly higher in the 11 samples obtained during AR than those obtained during PB (p < 0.0001), which decreased promptly after treatment. The receiver operator characteristic curve analysis of diagnostic ability yielded areas under the curve of 0.975 and 0.897 for AR (rejection activity index [RAI] ≥3) versus PB and versus non-AR (ADWR + PB). The dd-cfDNA levels during AR were elevated earlier and correlated more strongly with the RAI (r = 0.740) than aspartate aminotransferase/alanine aminotransferase. The dd-cfDNA levels were neither associated with graft fibrosis based on histology nor the status of donor-specific antibodies in PB samples.

CONCLUSIONS

Donor-derived cell-free DNA serves as a sensitive biomarker for detecting graft injuries in LTx. Further large-scale cohort studies are warranted to optimize its use in differentiating various post-LTx etiologies.

Protective Effects of Hydrogen Gas Inhalation for Hindlimb Ischaemia-Reperfusion Injury in a Mouse Model

OBJECTIVE

Ischaemia-reperfusion (I/R) injury is a severe post-operative complication that triggers an inflammatory response and causes severe damage. Hydrogen gas has anti-oxidant and anti-apoptotic properties and has been shown to be safe in humans. The study aimed to investigate whether hydrogen gas protects against skeletal muscle I/R injury.

METHODS

Experimental basic research using mice. A total of 160 eight to 10 week old albino laboratory bred strain of house mice (25.8 ± 0.68 g) were used in this study. The mice were cable tied to the hindlimb under anaesthesia and then placed in an anaesthesia box filled with air and 2% isoflurane (control group); 80 mice were additionally subjected to 1.3% hydrogen gas in this mix (hydrogen group). After two hours, the cable ties were removed to initiate reperfusion, and hydrogen inhalation lasted for six hours in the hydrogen group. After six hours, the mice were taken out of the box and kept in cages under standard conditions until time for observation at 16 different time points after reperfusion: zero, two, four, six, eight, and 10 hours and one, two, three, four, five, six, seven, 14, 21, and 28 days. Five mice were sacrificed using excess anaesthesia at each time point, and the bilateral hindlimb tissues were harvested. The inflammatory effects of the I/R injury were assessed by evaluating serum interleukin-6 concentrations using enzyme linked immunosorbent assay, as well as histological and immunohistochemical analyses. Untreated mice with I/R injury were used as controls.

RESULTS

Hydrogen gas showed protective effects associated with a reduction in inflammatory cell infiltration (neutrophils, macrophages, and lymphocytes), a reduced area of damaged muscle, maintenance of normal muscle cells, and replacement of damaged muscle cells with neoplastic myocytes.

CONCLUSION

Inhalation of hydrogen gas had a protective effect against hindlimb I/R injury in mice, in part by reducing inflammatory cell infiltration and in part by preserving normal muscle cells.

Cultural adaptation, content, and protocol of a feasibility study of school-based "Let's learn about emotions" intervention for Finnish primary school children

Introduction

Emotional awareness and emotion regulation are crucial for cognitive and socio-emotional development in children. School-based interventions on socio-emotional skills have the potential to prevent these problems and promote well-being of children. The Japanese school-based program, Universal Unified Prevention Program for Diverse Disorders (Up2-D2), has shown preventive effects on mental health of children in Japan. The aims of this protocol paper are to describe the unique process of adapting the Up2-D2 from Eastern to Western context, and to present a feasibility study of the intervention, conducted in Finland.

Methods

The cultural adaptation process started with the linguistic translation of materials, followed by the modification of language to fit the Finnish context. While the Japanese ideology was saved, some content was adapted to fit Finnish school children. Further modifications were made based on feedback from pupils and teachers. The Finnish version of the program was named "Let's learn about emotions" and consisted of 12 sessions and targeted 8- to 12-year-old pupils. A teacher education plan was established to assist Finnish teachers with the intervention, including a workshop, teachers' manual, brief introductory videos, and online support sessions. A feasibility study involving 512 4th graders in the City of Hyvinkää, South of Finland, was conducted. It assessed emotional and behavioral problems, classroom climate, bullying, loneliness, perception of school environment, knowledge of emotional awareness, and program acceptability.

Discussion

The originality of this study underlies in the East-West adaptation of a cognitive behavioral therapy-based program. If promising feasibility findings are replicated in Finland, it could pave the way for further research on implementing such programs in diverse contexts and cultures, promoting coping skills, awareness, social skills and early prevention of child mental health problems.

Ethics

The ethical board of the University of Turku gave ethics approval for this research. The educational board of the City of Hyvinkää accepted this study.

Five-year outcomes of the bioresorbable peripheral REMEDY stent in the treatment of iliac artery disease

PURPOSE

This study aimed to evaluate the five-year performance of a bioresorbable vascular scaffold, the REMEDY stent, for the treatment of iliac artery atherosclerotic disease.

MATERIALS AND METHODS

This prospective, multicenter, single-arm clinical study evaluated 97 patients (97 lesions) with symptomatic TransAtlantic Inter-Society Consensus II A/B iliac artery lesions for five years after stent placement. The primary efficacy endpoint was 12-month primary patency compared with the prespecified standard derived from historical data with metallic stents, and the primary safety endpoint was the occurrence of major adverse clinical events within five years. All angiography and computed tomography angiography findings were evaluated by an independent core laboratory for quantitative vessel analysis.

RESULTS

The 12-month primary patency rate was 88.6% (95% confidence interval, 80.1%-94.4%), below the prespecified standard. No significant difference was noted between the diameter stenosis at nine and 12 months. There were no device-/procedure-related deaths, major amputation, or distal embolization during the follow-up period. The ankle-brachial index maintained significant improvement through the five-year period compared with that at baseline. The Kaplan-Meier estimates of freedom from target lesion revascularization (TLR), major adverse cardiovascular events, and major adverse cardiovascular and limb events were 95.8%, 91.7%, and 87.5% at 12 months and 85.4%, 72.1%, and 62.5% at five years, respectively.

CONCLUSIONS

The five-year follow-up outcomes, including freedom from TLR, of the REMEDY stent in iliac artery lesions were satisfactory, with a good safety profile. Nevertheless, the 12-month primary patency did not meet the expected standard compared with that of contemporary metallic stents.

Standardized upfront Glissonean approach and liver hanging maneuver reduces bile leakage from the hepatic hilum in living donors

Biliary complications after hepatectomy in living donors have yet to be eradicated. We hypothesized that a standardized upfront Glissonean approach and liver hanging maneuver (GH) would prevent mechanical and thermal injuries to the hilar plate of the remnant liver by determining the point of bile duct division and the final destination of hepatectomy preceding liver parenchymal transection (safety) and facilitate liver transection deep within the parenchyma and allow maximum length of hilar structures (rationality). GH was implemented in 2016 and its incidence of bile leakage was retrospectively compared against the conventional technique. GH comprises six steps: (1) development of the retrohepatic avascular plane between the right hepatic vein (RHV) and the middle hepatic vein (MHV) and isolation of the hepatic vein(s); (2) isolation of the right or left Glissonean pedicle with the corresponding Glissonean pedicles of the caudate lobe; (3) for right liver grafts and left liver grafts with the caudate lobe, passage of the tape for the liver hanging maneuver along the retrohepatic avascular plane and above the hilar plate, and for left liver grafts without the caudate lobe and for left lateral section grafts, passage of the tape from between the RHV and the MHV, along the Arantius ligament, and to the right of the umbilical portion; (4) liver transection; (5) isolation of hilar structures; and (6) graft procurement. Until 2020, 62 consecutive living donors underwent GH (success rate, 100%). The incidence of bile leakage from the hepatic hilum (0%) was significantly lower than that among 59 donors who underwent the conventional technique in 2011-2015 (9%; p = 0.01). In conclusion, GH is highly effective in reducing bile leakage from the hepatic hilum in living donors.

Characteristics, Antithrombotic Patterns, and Prognostic Outcomes in Claudication and Critical Limb-Threatening Ischemia Undergoing Endovascular Therapy

Purpose:

The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study aimed to clarify differences in clinical features and prognostic outcomes between IC and CLTI, and prognostic factors in patients undergoing endovascular therapy (EVT).

Materials and Methods:

A total of 692 patients with 808 limbs were enrolled from 20 institutions in Japan. The primary measurements were the 3-year rates of major adverse cardiovascular event (MACE) and reintervention.

Results:

Among patients, 79.0% had IC and 21.0% had CLTI. Patients with CLTI were more frequently women and more likely to have impaired functional status, undernutrition, comorbidities, hypercoagulation, hyperinflammation, distal artery disease, short single antiplatelet and long anticoagulation therapies, and late cilostazol than patients with IC. Aortoiliac and femoropopliteal diseases were dominant in patients with IC and infrapopliteal disease was dominant in patients with CLTI. Patients with CLTI underwent less frequently aortoiliac intervention and more frequently infrapopliteal intervention than patients with IC. Longitudinal change of ankle-brachial index (ABI) exhibited different patterns between IC and CLTI (pinteraction=0.002), but ABI improved after EVT both in IC and in CLTI (p<0.001), which was sustained over time. Dorsal and plantar skin perfusion pressure in CLTI showed a similar improvement pattern (pinteraction=0.181). Distribution of Rutherford category improved both in IC and in CLTI (each p<0.001). Three-year MACE rates were 20.4% and 42.3% and 3-year reintervention rates were 22.1% and 46.8% for patients with IC and CLTI, respectively (log-rank p<0.001). Elevated D-dimer (p=0.001), age (p=0.043), impaired functional status (p=0.018), and end-stage renal disease (p=0.019) were independently associated with MACE. After considering competing risks of death and major amputation for reintervention, elevated erythrocyte sedimentation rate (p=0.003) and infrainguinal intervention (p=0.002) were independently associated with reintervention. Patients with CLTI merely showed borderline significance for MACE (adjusted hazard ratio 1.700, 95% confidence interval 0.950–3.042, p=0.074) and reintervention (adjusted hazard ratio 1.976, 95% confidence interval 0.999–3.909, p=0.05).

Conclusions:

The CLTI is characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared with IC. Also, CLTI has approximately twice MACE and reintervention rates than IC, and the underlying inflammatory coagulation disorder per se is associated with these outcomes.

Clinical Impact

The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study, JPASSION study found that CLTI was characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared to IC. Also, CLTI had approximately twice major adverse cardiovascular event (MACE) and reintervention rates than IC. Intriguingly, the underlying inflammatory coagulation disorder per se was independently associated with MACE and reintervention. Further studies to clarify the role of anticoagulation and anti-inflammatory therapies will contribute to the development of post-interventional therapeutics in the context of peripheral artery disease.

Prediction of need for bowel resection in acute superior mesenteric artery occlusion: A retrospective study of 48 Japanese patients

Aim

This study aimed to predict cases of acute superior mesenteric artery (SMA) occlusion requiring bowel resection using occlusion site and time from symptom onset to diagnosis at five Japanese institutions. Advances in imaging, endovascular treatment, and perioperative management have improved the clinical outcomes of patients with acute SMA occlusion; however, in clinical practice it remains difficult to effectively determine patients requiring bowel resection.

Methods

We retrospectively analyzed the data of 48 patients (mean age: 82.5 y; male: 37.5%) diagnosed with acute SMA occlusion between June 2009 and August 2018. Background data of patients who required and did not require bowel resection were compared. A multivariable predictive model was developed using the time from symptom onset to diagnosis and whether SMA occlusion was proximal, including the origin of the middle colic artery.

Results

Fifteen patients (31.3%) died during the hospital stay. Atrial fibrillation (83.3%) was the most common comorbidity. The median time from symptom onset to diagnosis was 13.0 (interquartile range, 4.75-24.0) h. Laparotomy, bowel resection, and thrombus embolectomy were performed in 41 (85.4%), 26 (54.2%), and 21 (43.8%) patients, respectively. A logistic regression model achieved 78.6% sensitivity in predicting cases not requiring bowel resection. Proximal occlusion was significantly associated with the requirement for bowel resection (P = .039).

Conclusion

The time from symptom onset to diagnosis and occlusion site contributed to high sensitivity in determining the need for bowel resection in patients with acute SMA occlusion. Further prospective studies are warranted to investigate the clinical impact of this model.

Reappraisal of liver transplantation for erythropoietic protoporphyria: A deadly combination of disease recurrence and biliary complication

BACKGROUND

Erythropoietic protoporphyria (EPP) is a rare inherited disorder that causes the accumulation of protoporphyrin in the erythrocytes, skin, and liver. Severe protoporphyric hepatopathy results in liver failure, requiring both liver and bone marrow transplantation as a life-saving procedure and to correct the underlying enzymatic defect, respectively.

CASE PRESENTATION

We report a 20-year-old man who underwent split liver transplantation using a right trisegment and caudate lobe graft for EPP-induced liver failure, but succumbed to a deadly combination of early relapse of EPP and subsequent, intractable, late-onset bile leakage from the cut surface of segment 4. EPP recurrence most likely created a high-risk situation for bile leakage from the non-communicating bile ducts of segment 4; therefore, this case shed light on the potential relationship between EPP recurrence and biliary complications.

CONCLUSION

Physicians should recognize the potentially rapid and life-threatening progression of protoporphyric hepatopathy that leads to liver failure. For young patients with EPP, LT and sequential BMT should thoroughly be considered by a multidisciplinary team as soon as hepatic reserve deterioration becomes evident. Split liver transplantation should preferably be avoided and appropriate post-transplant management is critical before protoporphyrin depositions to the bile duct and hepatocyte causes irreversible damage to the liver graft.

Long-term Outcomes of the Endurant and Excluder Stent Grafts for Endovascular Aneurysm Repair in a Japanese Cohort

PURPOSE

To compare the long-term outcomes of the most widely used third-generation stent grafts, the Endurant and Excluder stent grafts, in Japanese patients using a multicenter registry.

MATERIALS AND METHODS

A retrospective analysis of endovascular aneurysm repairs for abdominal aortic and iliac artery aneurysms using either the Endurant or the Excluder stent grafts from January 2012 to July 2019 at 10 Japanese hospitals was performed.

RESULTS

A total of 332 and 378 repairs using the Endurant and Excluder stent grafts, respectively, were analyzed. Although the patients' characteristics were generally similar in the two groups, the Endurant group exhibited significantly shorter (Endurant: 31.5±18.6 mm, Excluder: 37.4±21.0 mm; p<0.001), larger (Endurant: 22.4±4.2 mm, Excluder: 21.7±3.8 mm; p=0.029), and more reversed tapered (Endurant: 12.1%, Excluder: 5.8%; p=0.003) proximal necks. The incidence of instructions for use (IFU) violations was similar between the two groups (Endurant: 59.0%, Excluder: 54.5%; p=0.223). However, the Endurant group had significantly more proximal neck-related IFU violations (54.1% and 46.3%, respectively; p=0.039), more access-related IFU violations (8.1% and 4.0%, respectively; p=0.019), and fewer bilateral hypogastric artery embolizations (5.1% and 9.3%, respectively; p=0.035) compared with the Excluder group. The incidence of intraoperative (Endurant: 3.6%, Excluder: 3.7%; p=0.950) and perioperative complications (Endurant: 3.6%, Excluder: 3.4%, p=0.899) was equivalent in the two groups. However, there was a significantly higher incidence of postoperative type II endoleaks in the Excluder group (Endurant: 28%, Excluder: 46.0%, p<0.001). Aneurysm sac regression was more frequent in the Endurant group (Endurant: 40.7%, Excluder: 31.7%, p=0.013). The Endurant group also had significantly higher rates of sac increase (Endurant: 13.0%, Excluder: 7.7%, p=0.020). Kaplan-Meier curve and log-rank analyses revealed no statistical differences in late complications (p=0.868) and overall survival (p=0.926).

CONCLUSIONS

There were no statistically significant differences between the Endurant and the Excluder stent grafts in terms of intraoperative, perioperative, and late complication rates; however, the anatomical characteristics of the patients were significantly different.

Transplantation of bioengineered liver capable of extended function in a preclinical liver failure model

Unlimited organ availability would represent a paradigm shift in transplantation. Long-term in vivo engraftment and function of scaled-up bioengineered liver grafts have not been previously reported. In this study, we describe a human-scale transplantable liver graft engineered on a porcine liver-derived scaffold. We repopulated the scaffold parenchyma with primary hepatocytes and the vascular system with endothelial cells. For in vivo functional testing, we performed auxiliary transplantation of the repopulated scaffold in pigs with induced liver failure. It was observed that the auxiliary bioengineered liver graft improved liver function for 28 days and exhibited upregulation of liver-specific genes. This study is the first of its kind to present 28 days of posttransplant evaluation of a bioengineered liver graft using a preclinical large animal model. Furthermore, it provides definitive evidence for the feasibility of engineering human-scale transplantable liver grafts for clinical applications.

Patients with liver cirrhosis due to nonalcoholic steatohepatitis have lesser chances for liver transplantation

BACKGROUND

The main causes of liver cirrhosis have changed over the past decade. In Japan, the number of deceased donors is increasing but is still insufficient relative to the number of patients awaiting a liver transplant. This study aimed to assess the outcomes of candidates for liver transplantation.

METHODS

This was a retrospective study of adult patients who visited our department for consultation regarding liver transplantation from January 2009 to December 2020. Of a total of 601 patients, 336 were followed-up. The following data were collected and analyzed: patient's characteristics, liver etiology, Child-Pugh and MELD scores, and the eventual outcome, that is, whether liver transplantation was performed.

RESULTS

Only 153 of 336 (45.5%) patients underwent liver transplantation, of which 42 (27.5%) received deceased donor liver transplantation, and 129 (38.4%) died without transplantation. The proportion of patients who underwent liver transplantation was low among patients with nonalcoholic steatohepatitis (NASH) (10.7%) (P<0.001). The rate of qualified living donors was the lowest for patients with NASH (28.6%) and that for the other etiologies ranged from 55.6% to 67.4% (P=0.050).

CONCLUSION

Patients with liver cirrhosis due to NASH may have a lesser chance of undergoing liver transplantation from both living and deceased donors.

The hypotaurine-taurine pathway as an antioxidative mechanism in patients with acute liver failure

The liver has been thought to protect against oxidative stress through mechanisms involving reduced glutathione (GSH) that consumes high-energy phosphor-nucleotides on its synthesis. However, hepatoprotective mechanisms in acute liver failure (ALF) where the phosphor-nucleotides are decreased in remain to be solved. Liver tissues were collected from patients with ALF and liver cirrhosis (LC) and living donors (HD) who had undergone liver transplantation. Tissues were used for metabolomic analyses to determine metabolites belonging to the central carbon metabolism, and to determine sulfur-containing metabolites. ALF and LC exhibited a significant decline in metabolites of glycolysis and pentose phosphate pathways and high-energy phosphor-nucleotides such as adenosine triphosphate as compared with HD. Conversely, methionine, S-adenosyl-l-methionine, and the ratio of serine to 3-phosphoglycerate were elevated significantly in ALF as compared with LC and HD, suggesting a metabolic boost from glycolysis towards trans-sulfuration. Notably in ALF, the increases in hypotaurine (HTU) + taurine (TU) coincided with decreases in the total amounts of reduced and oxidized glutathione (GSH + 2GSSG). Plasma NH₃ levels correlated with the ratio of HTU + TU to GSH + 2GSSG. Increased tissue levels of HTU + TU vs total glutathione appear to serve as a biomarker correlating with hyperammonemia, suggesting putative roles of the HTU-TU pathway in anti-oxidative protective mechanisms.

Adipose-Derived Mesenchymal Stromal/Stem Cell Line Prevents Hepatic Ischemia/Reperfusion Injury in Rats by Inhibiting Inflammasome Activation

Mesenchymal stromal/stem cells (MSCs) have shown potential in the treatment of degenerative diseases, including ischemia/reperfusion injury (IRI), which occurs during organ transplantation and represents the main cause of post-transplant graft dysfunction. However, MSCs have heterogeneous characteristics, and studies of MSCs therapy have shown a variety of outcomes. To establish a new effective MSCs therapy, we developed an adipose-derived mesenchymal stromal/stem cell line (ASCL) and compared its therapeutic effects on primary adipose-derived MSCs (ASCs) using a hepatocyte co-culture model of hypoxia/reoxygenation in vitro and a rat model of hepatic IRI in vivo. The results showed that both ASCL and ASCs protect against hypoxia by improving hepatocyte viability, inhibiting reactive oxygen species release, and upregulating transforming growth factor-β in vitro. In vivo, ASCL or ASCs were infused into the spleen 24 h before the induction of rat hepatic IRI. The results showed that ASCL significantly improved the survival outcomes compared with the control (normal saline infusion) with the significantly decreased serum levels of liver enzymes and less damage to liver tissues compared with ASCs. Both ASCL and ASCs suppressed NOD-like receptor family pyrin domain-containing 3 inflammasome activation and subsequently reduced the release of activated IL-1β and IL-18, which is considered an important mechanism underlying ASCL and ASCs infusion in hepatic IRI. In addition, ASCL can promote the release of interleukin-1 receptor antagonist, which was previously reported as a key factor in hampering the inflammatory cascade during hepatic IRI. Our results suggest ASCL as a new candidate for hepatic IRI treatment due to its relatively homogeneous characteristics.

Diagnostic Utility of Presepsin in Infections After Liver Transplantation: A Preliminary Study

BACKGROUND Infectious complications after solid organ transplantation can be fatal, and early diagnosis and intervention are important. To the best of our knowledge, no study has examined the diagnostic utility of presepsin, a known accurate biomarker, for infectious complications after liver transplantation. This study aimed to evaluate the utility of presepsin for detecting infection and perioperative kinetics of presepsin after liver transplantation. MATERIAL AND METHODS This single-institutional prospective, observational study included 13 patients who underwent living-donor or deceased-donor liver transplantation. Perioperative serum presepsin level was measured 6 times within a week to evaluate its association with infectious complications and compare it with procalcitonin and C-reactive protein levels and leukocyte count. Postoperatively, patients were followed up for 15 days for infectious complications. RESULTS Five of the 13 patients developed infectious complications after liver transplantation. The median time for infection diagnosis was 9 postoperative days (25th-75th percentile, 7-10). Presepsin levels on 5 and 7 postoperative days were significantly higher in patients with infection than in those without (P=0.019 and P=0.011, respectively). In receiver operating characteristic analysis, area under the curve values of presepsin on 5 and 7 postoperative days (0.881 and 0.905, respectively) were higher than those of other biomarkers. The optimal cut-off value of presepsin was 1361 pg/mL on postoperative day 5 and 1375 pg/mL on postoperative day 7. CONCLUSIONS Although this study included a small number of patients, presepsin levels on postoperative days 5 and 7 may be useful indicators for infectious complications after liver transplantation.

Maintenance treatment with infliximab for ulcerative ileitis after intestinal transplantation: A case report

BACKGROUND

Evidence has been published on the successful applications of the anti-tumor necrosis factor alpha antibody infliximab, such as induction therapy, salvage treatment for acute cellular rejection, and treatment for chronic ulcerative inflammation, in intestinal transplant recipients. However, the optimal protocol for the effective use of infliximab remains largely undetermined due to scarcity of available clinical data. We report a continuative application of infliximab as maintenance therapy for recurrent chronic ulcerative ileitis in a recipient of isolated intestinal transplantation (ITx).

CASE SUMMARY

The patient was a 11-year-old boy with intestinal motility disorder classified as a hypogenic type of intestinal dysganglionosis. The patient underwent living-donor related intestinal transplant. His immunosuppression regimen consisted of daclizumab, tacrolimus, and steroids. Although he did not show rejection while on tacrolimus monotherapy, routine screening endoscopy showed several ulcerative lesions in the distal end of the graft 2 years after the intestinal transplant. Endoscopic work up to evaluate the progression of anemia revealed stenosis with ulcerative inflammatory changes and multiple longitudinal ulcers in the graft. Since the endoscopic findings suggested ulcerative lesions in Crohn’s disease, infliximab treatment was considered. Treatment with infliximab and a small dose of oral prednisolone afforded successful withdrawal of total parenteral nutrition and maintenance of a well-functioning graft without infectious complications for 5 years since the administration of the first dose of infliximab.

CONCLUSION

Infliximab is effective as maintenance therapy for recurrent chronic ulcerative ileitis in an isolated ITx patient.

Effects of Rice Wine Lees on Cognitive Function in Community-Dwelling Physically Active Older Adults: A Pilot Randomized Controlled Trial

BACKGROUND

Rice wine lees (RWL), a Japanese traditional fermented product, is a rich source of one-carbon metabolism-related nutrients, which may have beneficial effects on cognitive function.

OBJECTIVES

We aimed to examine the effect of the RWL on cognitive function in community-dwelling physically active older adults.

DESIGN

Double-blind, randomized, placebo-controlled study (clinical trial number: UMIN 000027158).

SETTING

Community-based intervention including assessments conducted at the University of Hyogo and a public liberal arts school in Himeji City, Japan.

PARTICIPANTS

A total of 35 community-dwelling older adults (68-80 years) who performed mild exercise before and during the trial were assigned to either the RWL (n=17) or the placebo group (n=18).

INTERVENTION

Daily consumption of 50 g RWL powder, which contained one-carbon metabolism-related nutrients, or the placebo powder (made from soy protein and dextrin) for 12 weeks. Both supplements included equivalent amounts of energy and protein.

MEASUREMENTS

Montreal Cognitive Assessment, computerized cognitive function test, and measurements of serum predictive biomarkers (transthyretin, apolipoprotein A1, and complement C3) were conducted at baseline and follow-up.

RESULTS

Visual selective attention and serum transthyretin significantly improved in the RWL group, whereas there was no significant change in the placebo group. No significant group difference was observed in the remaining cognitive performance tests.

CONCLUSIONS

RWL supplements seem to have a few effects on cognitive function in community-dwelling physically active older adults. However, the impact was limited; therefore, further studies with sufficient sample size are warranted to elucidate this issue.

Assembly and Function of a Bioengineered Human Liver for Transplantation Generated Solely from Induced Pluripotent Stem Cells

The availability of an autologous transplantable auxiliary liver would dramatically affect the treatment of liver disease. Assembly and function in vivo of a bioengineered human liver derived from induced pluripotent stem cells (iPSCs) has not been previously described. By improving methods for liver decellularization, recellularization, and differentiation of different liver cellular lineages of human iPSCs in an organ-like environment, we generated functional engineered human mini livers and performed transplantation in a rat model. Whereas previous studies recellularized liver scaffolds largely with rodent hepatocytes, we repopulated not only the parenchyma with human iPSC-hepatocytes but also the vascular system with human iPS-endothelial cells, and the bile duct network with human iPSC-biliary epithelial cells. The regenerated human iPSC-derived mini liver containing multiple cell types was tested in vivo and remained functional for 4 days after auxiliary liver transplantation in immunocompromised, engineered (IL2rg^-/-) rats.

Infected abdominal aorta aneurysm secondary to streptococcal toxic shock syndrome due to Streptococcus pyogenes: a case report from Japan

Background

Infected aortic aneurysm secondary to streptococcal toxic shock syndrome caused by Streptococcus pyogenes is uncommon and associated with high mortality.

Case presentation

A 75‐year‐old man with metastatic lung cancer and an abdominal aortic aneurysm presented with high fever for 3 days. He was diagnosed with septic shock and was admitted to our hospital. The blood culture was positive for S. pyogenes, and streptococcal toxic shock syndrome was diagnosed. During treatment, enhanced computed tomography revealed an increase in the size of the abdominal aortic aneurysm, leading to the diagnosis of an infected aortic aneurysm. Replacement of the aneurysm with a synthetic graft was carried out successfully. The patient gradually recovered after the surgery.

Conclusion

We successfully managed an infected aortic aneurysm secondary to streptococcal toxic shock syndrome. Infected aortic aneurysms should be considered in patients with a medical history of aortic aneurysms and presenting with streptococcal toxic shock syndrome.

First Successful Delivery after Uterus Transplantation in MHC-Defined Cynomolgus Macaques

Delivery following uterus transplantation (UTx)—an approach for treating uterine factor infertility—has not been reported in nonhuman primate models. Here, six female major histocompatibility complex (MHC)-defined cynomolgus macaques that underwent allogeneic UTx were evaluated. Antithymocyte globulin and rituximab were administered to induce immunosuppression and a triple maintenance regimen was used. Menstruation resumed in all animals with long-term survival, except one, which was euthanized due to infusion associated adverse reaction to antithymocyte globulin. Donor-specific antibodies (DSA) were detected in cases 2, 4, and 5, while humoral rejection occurred in cases 4 and 5. Post-transplant lymphoproliferative disorder (PTLD) developed in cases 2 and 3. Pregnancy was attempted in cases 1, 2, and 3 but was achieved only in case 2, which had haploidentical donor and recipient MHCs. Pregnancy was achieved in case 2 after recovery from graft rejection coincident with DSA and PTLD. A cesarean section was performed at full-term. This is the first report of a successful livebirth following allogeneic UTx in nonhuman primates, although the delivery was achieved via UTx between a pair carrying haploidentical MHCs. Experimental data from nonhuman primates may provide important scientific knowledge needed to resolve unsolved clinical issues in UTx.

Experimental techniques for the development of a uterus transplantation model in cynomolgus macaques

Uterus transplantation (UTx) is now a treatment for women with uterine factor infertility to have a child. However, UTx is still largely at the experimental stage, and many medical issues remain unsolved. Therefore, adequate studies in large animals including non-human primates are required for validation of these issues. UTx research, especially in non-human primates, can provide important information for its full establishment in humans due to the anatomical and physiological similarities between the two. We accumulated data from UTx studies using cynomolgus macaques since 2009 and established autologous and allogeneic UTx models which led to deliveries after performing the procedure. In this paper, we summarized key points to develop UTx models in cynomolgus macaques based on our experience. UTx models in non-human primates can surely contribute new and beneficial knowledge in this field and can be useful for the further development of UTx in humans.

Aneuploid rescue precedes X-chromosome inactivation and increases the incidence of its skewness by reducing the size of the embryonic progenitor cell pool

STUDY QUESTION

Do monosomy rescue (MR) and trisomy rescue (TR) in preimplantation human embryos affect other developmental processes, such as X-chromosome inactivation (XCI)?

SUMMARY ANSWER

Aneuploid rescue precedes XCI and increases the incidence of XCI skewness by reducing the size of the embryonic progenitor cell pools.

WHAT IS KNOWN ALREADY

More than half of preimplantation human embryos harbor aneuploid cells, some of which can be spontaneously corrected through MR or TR. XCI in females is an indispensable process, which is predicted to start at the early-blastocyst phase.

STUDY DESIGN, SIZE, DURATION

We examined the frequency of XCI skewness in young females who carried full uniparental disomy (UPD) resulting from MR or TR/gamete complementation (GC). The results were statistically analyzed using a theoretical model in which XCI involves various numbers of embryonic progenitor cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We studied 39 children and young adults ascertained by imprinting disorders. XCI ratios were determined by DNA methylation analysis of a polymorphic locus in the androgen receptor gene. We used Bayesian approach to assess the probability of the occurrence of extreme XCI skewness in the MR and TR/GC groups using a theoretical model of 1-12 cell pools.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 12 of 39 individuals (31%) showed skewed XCI. Extreme skewness was observed in 3 of 15 MR cases (20%) and 1 of 24 TR/GC cases (4.2%). Statistical analysis indicated that XCI in the MR group was likely to have occurred when the blastocyst contained three or four euploid embryonic progenitor cells. The estimated size of the embryonic progenitor cell pools was approximately one-third or one-fourth of the predicted size of normal embryos. The TR/GC group likely had a larger pool size at the onset of XCI, although the results remained inconclusive.

LIMITATIONS, REASONS FOR CAUTION

This is an observational study and needs to be validated by experimental analyses.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides evidence that the onset of XCI is determined by an intrinsic clock, irrespectively of the number of embryonic progenitor cells. Our findings can also be applied to individuals without UPD or imprinting disorders. This study provides a clue to understand chromosomal and cellular dynamics in the first few days of human development, their effects on XCI skewing and the possible implications for the expression of X-linked diseases in females.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Grants-in-aid for Scientific Research on Innovative Areas (17H06428) and for Scientific Research (B) (17H03616) from Japan Society for the Promotion of Science (JSPS), and grants from Japan Agency for Medical Research and Development (AMED) (18ek0109266h0002 and 18ek0109278h0002), National Center for Child Health and Development and Takeda Science Foundation. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Clinical features of irreversible rejection after allogeneic uterus transplantation in cynomolgus macaques

Uterus transplantation (UTx) is a potential option for women with uterine factor infertility to have a child. The clinical features indicating irreversible rejection of the uterus are unknown. In our experimental series of allogeneic UTx in cynomolgus macaques, six female macaques were retrospectively examined, which were unresponsive to treatment with immunosuppressants (i.e. irreversible rejection). Clinical features including general condition, hematology, uterine size, indocyanine green (ICG) fluorescence imaging by laparotomy, and histopathological findings of the removed uterus were evaluated. In all cases, general condition was good at the time of diagnosis of irreversible rejection and thereafter. Laboratory evaluation showed temporary increases in white blood cells, lactate dehydrogenase and C-reactive protein, then these levels tended to decrease gradually. In transabdominal ultrasonography, the uterus showed time-dependent shrinkage after transient swelling at the time of diagnosis of irreversible rejection. In laparotomy, a whitish transplanted uterus was observed and enhancement of the transplanted uterus was absent in ICG fluorescence imaging. Histopathological findings in each removed uterus showed hyalinized fibrosis, endometrial deficit, lymphocytic infiltration and vasculitis. These findings suggest that uterine transplantation rejection is not fatal, in contrast to rejection of life-supporting organs. Since the transplanted uterus with irreversible rejection atrophies naturally, hysterectomy may be unnecessary.

Myelopathy due to human T-cell leukemia virus type-1 from the donor after ABO-incompatible liver transplantation

We report the case of a 53-year-old-man who developed human T-cell leukemia virus type-1-associated myelopathy (HAM) after ABO-incompatible liver transplantation for alcoholic liver cirrhosis. The living donor was seropositive for human T-cell leukemia virus type-1 (HTLV-1) and the recipient was seronegative for HTLV-1 before transplantation. After transplantation, the recipient developed steroid-resistant acute cellular rejection, which was successfully treated using anti-thymocyte globulin, and he was eventually discharged. He underwent spinal surgery twice after the transplantation for the treatment of cervical spondylosis that had been present for a period of 9 months before the transplantation. The surgery improved his gait impairment temporarily. However, his gait impairment progressed, and magnetic resonance imaging revealed multiple sites of myelopathy. He was diagnosed with HAM 16 months after the transplantation. Pulse steroid therapy (1000mg) was administered over a period of 3 days, and his limb paresis improved. Presently, steroid therapy is being continued, with a plan to eventually taper the dose, and he is being carefully followed up at our institution. Our case suggests that liver transplantation involving an HTLV-1-positive living donor carries the risk of virus transmission and short-term development of HAM after transplantation.

Midterm Results of a Japanese Prospective Multicenter Registry of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Above-the-Knee Femoropopliteal Bypass

BACKGROUND

This study prospectively analyzed the midterm results of above-the-knee femoropopliteal bypass (AKb) using bioactive heparin-bonded expanded polytetrafluoroethylene (HB-ePTFE) graft in patients with femoropopliteal occlusive disease.Methods and Results:This prospective, multicenter, non-randomized study reviewed limbs undergoing AKb with HB-ePTFE graft for femoropopliteal lesion in 20 Japanese institutions between July 2014 and October 2017. Primary efficacy endpoints were primary, primary assisted, and secondary graft patency. Safety endpoints included any major adverse limb event and perioperative mortality. During the study period, 120 limbs of 113 patients (mean age, 72.7 years) underwent AKb with HB-ePTFE grafts. A total of 45 patients (37.5%) had critical limb ischemia and 17 (15.0%) were on hemodialysis (HD). Median duration of follow-up was 16 months (range, 1-36 months). Estimated 1- and 2-year primary, primary assisted, and secondary graft patency rates were 89.4% and 82.7%, 89.4% and 87.2%, and 94.7% and 92.5%, respectively. On univariate analysis of 2-year primary graft patency, having 3 run-off vessels, cuffed distal anastomoses, no coronary artery disease, and no chronic kidney disease requiring HD were significantly associated with favorable patency.

CONCLUSIONS

AKb using HB-ePTFE grafts achieved favorable 2-year graft patency. AKb using HB-ePTFE grafts may therefore be an acceptable, highly effective treatment option for femoropopliteal artery lesions.

Methicillin-resistant Staphylococcus aureus carriers are vulnerable to bloodstream infection after living donor liver transplantation

BACKGROUND

Bloodstream infection (BSI) is a life-threatening complication after living donor liver transplantation (LDLT). We aimed to explore the incidence and predisposing factors of BSI at our institution.

METHODS

We conducted a retrospective cohort analysis on all consecutive adults with BSI within 6 months after LDLT performed between 2005 and 2016. For antimicrobial prophylaxis, ampicillin/sulbactam, cefotaxime, and micafungin were administered. From 2011, methicillin-resistant Staphylococcus aureus (MRSA) carriers were decolonized using mupirocin ointment and chlorhexidine gluconate soap. Risk factors for BSI were identified by uni- and multivariate logistic regression.

RESULTS

Of a total of 106 LDLTs, 42 recipients (40%) suffered BSI. The BSI group demonstrated significantly higher in-hospital mortality rates compared with the non-BSI group (24% vs. 7%, P = .01). We identified MRSA carrier (odds ratio [OR], 19.1; P < .001), ABO incompatibility (OR, 2.9; P = .03), and estimated glomerular filtration rate <30 mL/min/1.73m² (OR, 15.8; P = .02) as independent risk factors for BSI. Decolonization treatment for MRSA carriers did not reduce the incidence of all-cause BSI but reduced the frequency of BSI caused by MRSA.

CONCLUSION

To our knowledge, for the first time, MRSA carriers were revealed to be highly vulnerable to BSI after LDLT.

Impact of Stent Graft Design on External Iliac Artery Limb Occlusion Rates After Endovascular Aneurysm Repair: Post-hoc Analysis of a Japanese Multicentre Database

OBJECTIVE/BACKGROUND

It was hypothesised that a helical stent with expanded polytetrafluoroethylene (ePTFE) grafts could provide a preventive effect for external iliac artery (EIA) limb occlusion following endovascular aortic aneurysm repair (EVAR). Therefore, a post-hoc analysis of a Japanese multicentre database was conducted to assess the impact of the stent graft design on EIA limb occlusion rates.

METHODS

Patients who underwent EVAR with EIA limb deployment between 2008 and 2016 were evaluated. The stent graft limbs were divided into two groups: group A comprised stent graft limbs made of a helical stent with ePTFE grafts (Excluder; n = 255), and group B comprised stent graft limbs made of a Z stent with polyester grafts (Zenith, Flex and Endurant; n = 173). The main outcome was the incidence of limb occlusion and severe limb stenosis (EIA related limb complications). The risk factors for EIA related limb complications were analysed and the midterm results between groups A and B compared. Fine-Gray generalisation of the proportional hazards model was used after propensity score matching to calculate the hazard ratio (HR).

RESULTS

One complication occurred in group A and 10 complications occurred in group B. The risk factors for EIA related limb complications for the entire group were a stent graft limb size ≤10 mm (HR 5.41; p = .01) and inclusion in group B (HR 14.9; p = .009). After propensity matching, group A (n = 159) was matched with group B (n = 159). The cumulative incidence function of EIA related limb complications at five years was 0.66% in group A and 7.8% in group B (HR 8.67; p = .039).

CONCLUSION

Stent graft design can affect limb patency in EIA limb deployment. When EIA limb deployment is necessary for patients with a small EIA, such as Japanese patients, stent graft limbs made of a helical stent with ePTFE should be used to reduce the risk of limb occlusion.

Long-Term Outcome and Rejection After Allogeneic Uterus Transplantation in Cynomolgus Macaques

Uterus transplantation (UTx) is an option for women with uterine factor infertility to have a child, but is still in the experimental stage. Therefore, allogeneic animal models of UTx are required for resolution of clinical issues. In this study, long-term outcomes were evaluated in four recipients (cases 1-4) after allogeneic UTx in cynomolgus macaques. Immunosuppression with antithymocyte globulin induction and a triple maintenance regimen was used. Postoperative ultrasonography and biopsy of the transplanted uterus and immunoserological examinations were performed. All four recipients survived for >3 months after surgery, but continuous menstruation did not resume, although temporary menstruation occurred (cases 1 and 2). All animals were euthanized due to irreversible rejection and no uterine blood flow (cases 1, 2 and 4) and post-transplant lymphoproliferative disorder (case 3). Donor-specific antibodies against MHC class I and II were detected in cases 1, 2 and 4, but not in case 3. Peripheral lymphocyte counts tended to elevate for CD3⁺, CD20⁺ and NK cells in conjunction with uterine rejection, and all animals had elevated stimulation indexes of mixed lymphocyte reaction after surgery. Establishment of allogeneic UTx in cynomolgus macaque requires further exploration of immunosuppression, but the clinicopathological features of uterine rejection are useful for development of human UTx.

Living Donor Liver Re-Transplantation for Recurrent Hepatoblastoma in the Liver Graft following Complete Eradication of Peritoneal Metastases under Indocyanine Green Fluorescence Imaging

The curability of chemotherapy-resistant hepatoblastoma (HB) largely depends on the achievement of radical surgical resection. Navigation techniques utilizing indocyanine green (ICG) are a powerful tool for detecting small metastatic lesions. We herein report a patient who underwent a second living donor liver transplantation (LDLTx) for multiple recurrent HBs in the liver graft following metastasectomy for peritoneal dissemination with ICG navigation. The patient initially presented with ruptured HB at 6 years of age and underwent 3 liver resections followed by the first LDLTx with multiple sessions of chemotherapy at 11 years of age. His alpha-fetoprotein (AFP) level increased above the normal limit, and metastases were noted in the transplanted liver and peritoneum four years after the first LDLTx. The patient underwent metastasectomy of the peritoneally disseminated HBs with ICG navigation followed by the second LDLTx for multiple metastases in the transplanted liver. The patient has been recurrence-free with a normal AFP for 30 months since the second LDLTx. To our knowledge, this report is the first successful case of re-LDLTx for recurrent HBs. Re-LDLTx for recurrent HB can be performed in highly select patients, and ICG navigation is a powerful surgical tool for achieving tumor clearance.

Colon perforation due to antigenemia-negative cytomegalovirus gastroenteritis after liver transplantation: A case report and review of literature

BACKGROUND

Cytomegalovirus (CMV) remains a critical complication after solid-organ transplantation. The CMV antigenemia (AG) test is useful for monitoring CMV infection. Although the AG-positivity rate in CMV gastroenteritis is known to be low at onset, almost all cases become positive during the disease course. We treated a patient with transverse colon perforation due to AG-negative CMV gastroenteritis, following a living donor liver transplantation (LDLT).

CASE SUMMARY

The patient was a 52-year-old woman with decompensated liver cirrhosis as a result of autoimmune hepatitis who underwent a blood-type compatible LDLT with her second son as the donor. On day 20 after surgery, upper and lower gastrointestinal endoscopy (GE) revealed multiple gastric ulcers and transverse colon ulcers. The biopsy tissue immunostaining confirmed a diagnosis of CMV gastroenteritis. On day 28 after surgery, an abdominal computed tomography revealed transverse colon perforation, and simple lavage and drainage were performed along with an urgent ileostomy. Although the repeated remission and aggravation of CMV gastroenteritis and acute cellular rejection made the control of immunosuppression difficult, the upper GE eventually revealed an improvement in the gastric ulcers, and the biopsy samples were negative for CMV. The CMV-AG test remained negative, therefore, we had to evaluate the status of the CMV infection on the basis of the clinical symptoms and GE.

CONCLUSION

This case report suggests a monitoring method that could be useful for AG-negative CMV gastroenteritis after a solid-organ transplantation.

The effectiveness of bismuth breast shielding with protocol optimization in CT Thorax examination

BACKGROUND

Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding.

OBJECTIVE

This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from CT thorax examination.

METHODS

Five protocols comprising the standard CT thorax clinical protocol (CP1) and four modified protocols (CP2 to CP5) were applied in anthropomorphic phantom scans. The phantom was configured as a female by placing a breast component on the chest. The breast component was divided into four quadrants, where 2 thermoluminescence dosimeters (TLD-100) were inserted into each quadrant to measure the absorbed dose. The bismuth shield was placed over the breast component during CP4 and CP5 scans.

RESULTS

The pattern of absorbed doses in each breast and quadrant were approximately the same for all protocols, where the 4th quadrant > 3rd quadrant > 2nd quadrant > 1st quadrant. The mean absorbed dose value in CP3 was reduced to almost 34% of CP1's mean absorbed dose. It was reduced even lower to 15% of CP1's mean absorbed dose when the breast shield was used in CP5.

CONCLUSION

This study showed that CT radiation exposure on the breast could be reduced by using a bismuth shield and low tube potential protocol without compromising the image quality.

Acute Limb Ischemia

Acute limb ischemia (ALI) is a rapid decrease in lower limb blood flow due to acute occlusion of peripheral artery or bypass graft, and in ALI not only limbs but also life prognosis will be poor unless quick and appropriate treatment is given. The etiology is broadly divided into embolism and thrombosis with various comorbidities. The symptoms of ALI are abrupt with pain, numbness, and coldness of lower limb, and paresthesia, contracture, and irreversible purpura will appear with the exacerbation of ischemia. Severity and treatment strategy should be determined based on physical findings and image findings. Considering life prognosis, limb amputation should be done without hesitation when the limb was diagnosed as irreversible. ALI can be treated by means of open surgical revascularization, endovascular, or hybrid approach with rapid systemic administration of heparin. In any cases, evaluating the lesions by intraoperative angiography and appropriate additional treatment are important. ALI is a serious disease requiring urgent treatment, and it is essential to promptly perform the best initial treatment that can be performed at each facility. (This is a translation of Jpn J Vasc Surg 2018; 27: 109–114.)