Validation of I71.3 code for ruptured abdominal aortic aneurysm in Korea: misplaced diagnosis in claims data

Purpose@#Studies in western countries have shown a decline in the incidence of ruptured abdominal aortic aneurysm (rAAA) with advancements in endovascular repair and screening. However, according to health insurance data in Korea based on rAAA code (I71.3), overall rAAA has been increasing. This study aimed to validate the I71.3 code for rAAA and attempt to define the true incidence of rAAA in Korea. @*Methods@#A 20-year multicenter retrospective review of rAAA was undertaken from the period of January 1, 2000 to December 31, 2020. All patients were diagnosed with the rAAA code I71.3 in each of the 4 hospitals. The CT images and surgical records of these patients were reviewed to differentiate true rAAA and misdiagnosis. Further data on true rAAA patient outcomes including mortality and treatment success were also collected. @*Results@#A total of 305 rAAA (I71.3) codes were identified in the 4 centers. However, medical record review showed true rAAA in only 131 (43.0%). The remaining 174 cases (57.0%) were misdiagnosed. Impending ruptures were the most common misdiagnoses (37.9%). The total in-hospital mortality including deaths before treatment was 38.9% (n = 51), while mortality of treated patients was 24.4% (n = 15). @*Conclusion@#The analysis of I71.3 code for rAAA showed that only 43.0% were true rAAA and the remaining 57.0% were misdiagnosed. This indicates that the I71.3 code is overestimated in National Health Insurance-based data and that the true incidence of rAAA could be much lower.

The Clinical Course and Prognosis of Patients With Nontuberculous Mycobacterial Pulmonary Disease After Solid Organ Transplantation

Background@#Due to impaired cell-mediated immunity, solid organ transplantation (SOT) recipients are at increased risk of developing nontuberculous mycobacterial pulmonary disease (NTM-PD). However, the clinical course of NTM-PD in SOT patients and the impact of SOT on the prognosis of NTM-PD remain unclear. @*Methods@#We analyzed patients who developed NTM-PD after receiving SOT between January 2001 and December 2020, at a tertiary referral hospital in South Korea. Baseline characteristics, clinical course, and prognosis were evaluated. Propensity score-matched analysis was performed to assess the impact of SOT on long-term survival in patients with NTM-PD. @*Results@#Among 4,685 SOT recipients over 20 years, 12 patients (median age, 64 years;interquartile range [IQR], 59–67 years; men, 66.7%) developed NTM-PD. Seven (58.3%) and five (41.7%) patients underwent kidney and liver transplantation, respectively, before the diagnosis of NTM-PD. The incidence of NTM-PD was 35.6 cases per 100,000 person-years among kidney transplant recipients and 28.7 cases per 100,000 person-years among liver transplant recipients. The median time between transplantation and the diagnosis of NTMPD was 3.3 (IQR, 1.5–10.8) years. The most common mycobacterial species was Mycobacterium avium (50.0%). Antibiotic treatment was initiated in five (41.7%) patients, and two patients (40.0%) achieved microbiological cure. Two patients died during a median follow-up of 4.2 (IQR, 2.3–8.8) years and NTM-PD was assumed to be the cause of death in one patient. When matched to patients without a history of SOT, patients with a history of SOT did not show worse survival (P value for log-rank test = 0.62). @*Conclusion@#The clinical course of NTM-PD in SOT recipients was comparable to that of patients without SOT, and SOT did not increase the risk of all-cause mortality in patients with NTM-PD.

Kidney Transplantation From Deceased Donors With Bloodstream Infection: A Multicenter Retrospective Study

Background@#The use of organs from donors with infection is limited because of the possibility of transmission. We aimed to investigate the transmission after deceased donor transplantation with bloodstream infection (BSI). @*Methods@#A retrospective study of patients undergoing kidney or pancreas transplantation at five tertiary centers in Korea from January 2009 and November 2019 was performed. We analyzed the outcomes after transplantation from deceased donors with BSI. @*Results@#Eighty-six recipients received transplantation from 69 donors with BSI. The most common isolated pathogens from donors were Gram-positive bacteria (72.0%), followed by Gram-negative bacteria (22.7%), and fungi (5.3%). Appropriate antimicrobial agents were used in 47.8% of donors before transplantation. Transmission occurred only in 1 of 83 recipients (1.2%) from bacteremic donors and 1 of 6 recipients (16.7%) from fungemic donors. One-year patient and graft survival was 97.5%and 96.3%, respectively. There was no significant difference in graft and patient survival between patients who received organs from infected donors and noninfected donors. @*Conclusion@#Using organs from donors with bacteremia seems to be a safe option with low transmission risk. The overall prognosis of using organs from donors with BSI is favorable.

Flat Pattern Peaks of Tacrolimus Absorption and Associated Pharmacogenomic Variants in Kidney Transplantation Recipients

Background@#Tacrolimus is the most commonly used immunosuppressive drug in solid organ transplantation. After administering a conventional twice-daily dose of tacrolimus, peak levels were achieved within the first 1.5 to 2 hours. A group of patients showed different early absorption phase of tacrolimus after kidney transplantation. @*Methods@#Trough(C0 ) and 1.5-hour blood levels (C1.5 ) of tacrolimus were measured in 95 kidney transplantation recipients. Patients with a C1.5 /C0 1.5 were defined as those having flat pattern peaks and as controls, respectively. Transplantation outcomes were compared between the groups. Whole exome sequencing was performed to investigate the genetic susceptibility to flat pattern peaks. @*Results@#Twenty-eight patients showed flat pattern peaks. The mean C1.5 /C0 values were 1.13 ± 0.22 and 3.78 ± 1.25 in the flat pattern peak and control groups, respectively. In multivariate analysis, flat pattern peak was an independent risk factor for biopsy-proven acute rejection (BPAR) and/or borderline change (P = 0.014). Patients having flat pattern peaks showed significantly lower post-transplant 36-month estimated glomerular filtration rate (P = 0.001). Two single nucleotide variants in ABCB1 genes, rs1922242 and rs2235035, were associated with flat pattern peaks (P = 0.019 and P = 0.027, respectively). @*Conclusion@#Both of C1.5 and C0should be measured to distinguish the patients showing unique initial absorption. A C1.5 /C0 ratio lower than 1.5 was associated with an increased risk of BPAR and/or borderline change. Single nucleotide variants s in ABCB1 gene might influence the flat pattern peaks of tacrolimus absorption.

Surgical Removal of Migrated Atrial Septal Defect Closure Device: A Case Report

Percutaneous closure of atrial septal defects (ASDs) has emerged as an alternative to surgical treatment; however, several early and late complications have been reported. In this report, we present the case of a patient who underwent surgical removal of a migrated ‘Figulla Flex II’ ASD occlusion device at the aortic bifurcation 2 months after ASD occlusion.

Intravascular Fasciitis in the Femoral Vein with Hypermetabolic Signals Mimicking a Sarcoma:The Role of Preoperative Imaging Studies with Review of Literature

Intravascular fasciitis (IVF) is a very rare disease that is difficult to diagnose preoperatively. Frequently, it can be misdiagnosed as a malignancy or deep vein thrombosis. A 26-year-old man presented with a 6-month history of intermittent cramping pain in the right calf. Duplex ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography were performed in various hospitals. The work-up revealed a hypermetabolic mass in the femoral vein, suggestive of a malignancy, such as leiomyosarcoma. The tumor was located inside the femoral vein with no invasion, and the mass was resected en bloc with the vein wall. Intraoperative frozen section biopsy revealed no malignancy, and the final pathological diagnosis was IVF. Herein, we report a case of IVF and discuss the role of imaging studies in its preoperative diagnosis, with an extensive literature review.

Stump Length Changes after Endovenous Cyanoacrylate Closure or Radiofrequency Ablation for Saphenous Vein Incompetence

Purpose@#The aim of this study was to analyze changes in stump length over time in patients with saphenous vein incompetence treated with cyanoacrylate closure (CAC) or radiofrequency ablation (RFA). @*Materials and Methods@#We retrospectively analyzed data collected from patients with saphenous vein incompetence who underwent either CAC or RFA at Seoul National University Hospital between November 2015 and December 2018. The stump lengths were measured using duplex ultrasonography (DUS) within 1 month and 6 months after treatment. The Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ) score were used to assess clinical outcomes. @*Results@#A total of 97 veins (64 great saphenous veins and 33 small saphenous veins) were analyzed. The stump length was not significantly different between the two groups at <1 month (P=0.311). However, the stump length in the CAC group was significantly longer than that in the RFA group at 6 months (P=0.004).At 6 months, the mean change in stump length was 1.41±2.28 cm in the CAC group and 0.51±0.54 cm in the RFA group (P=0.006). The VCSSs and AVVQ scores significantly improved after both procedures but were not significantly different between the two groups. @*Conclusion@#DUS at 6 months after treatment showed that the stump length in the CAC group increased more than that in the RFA group. No other factors affected the changes in stump length.

Better Efficacy of Balloon Assisted Maturation in Radial-Cephalic Arteriovenous Fistula for Hemodialysis

Purpose@#Native arteriovenous fistula (AVF) is the first choice for hemodialysis access; however, the maturation failure rate remains high. Hence, balloon-assisted maturation (BAM) is increasingly being used to overcome maturation failure. This study evaluated the outcomes of BAM and compared the differences between radial-cephalic (RC) and brachial-cephalic (BC) AVF. @*Materials and Methods@#Between January 2013 and December 2017, 1,622 new AVFs were created. BAM was considered if the AVF did not satisfy the criteria for hemodynamic maturation (6-mm diameter and 500-mL/min flow rate within 8 weeks after the operation). @*Results@#Of the 1,622 AVFs, BAM was performed in 142 patients (8.75%). There were 92 RC and 50 BC AVFs. Multivariate analyses revealed that ipsilateral central vein catheter history was the sole risk factor for maturation failure after BAM. Oneyear functional primary patency (FPP) and functional secondary patency (FSP) in RC AVFs were higher than those in BC AVFs without statistical significance (FPP, RC vs. BC: 70.9% vs. 50.9%, P=0.099; FSP, 95.5% vs. 81.1%, P=0.146). Further, based on the multivariate analysis, the independent risk factors for FPP in the RC and BC AVFs were the number of BAMs (odds ratio [OR], 3.05; 95% confidence interval [CI], 1.11-8.37; P=0.03) and age (OR, 1.04; 95% CI, 1.00-1.07; P=0.04), respectively. @*Conclusion@#BAM is a relatively good salvage method with tolerable patency. However, the risk factors for patency and the outcomes of BAM differ between RC and BC AVFs.

Do Not Tunnel the Small Bowel during the Tunneling of a Femoro-Femoral Bypass

A 62-year-old male with a history of femoro-femoral crossover bypass surgery 31 months previously presented with recurrent symptoms of fever and chills, along with a previous positive blood culture. Computed tomography showed vegetation in the bypass graft located in the peritoneal cavity, closely abutting the small bowel and soft tissue lesions in the right proximal thigh and distal calf. Under high suspicion of graft-enteric fistula with metastatic infection, surgery was performed to remove the previous graft and insert a new femoro-femoral bypass graft subcutaneously. Small bowel resection and anastomosis were also performed because the graft penetrated the small bowel mesentery and eroded into the small bowel.The patient had a patent graft without infection for more than 10 years. This case demonstrates the importance of tunneling in femoro-femoral crossover bypass free from the small bowel or other intraperitoneal organs.

Intravascular Fasciitis in the Femoral Vein with Hypermetabolic Signals Mimicking a Sarcoma:The Role of Preoperative Imaging Studies with Review of Literature

Intravascular fasciitis (IVF) is a very rare disease that is difficult to diagnose preoperatively. Frequently, it can be misdiagnosed as a malignancy or deep vein thrombosis. A 26-year-old man presented with a 6-month history of intermittent cramping pain in the right calf. Duplex ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography were performed in various hospitals. The work-up revealed a hypermetabolic mass in the femoral vein, suggestive of a malignancy, such as leiomyosarcoma. The tumor was located inside the femoral vein with no invasion, and the mass was resected en bloc with the vein wall. Intraoperative frozen section biopsy revealed no malignancy, and the final pathological diagnosis was IVF. Herein, we report a case of IVF and discuss the role of imaging studies in its preoperative diagnosis, with an extensive literature review.

Stump Length Changes after Endovenous Cyanoacrylate Closure or Radiofrequency Ablation for Saphenous Vein Incompetence

Purpose@#The aim of this study was to analyze changes in stump length over time in patients with saphenous vein incompetence treated with cyanoacrylate closure (CAC) or radiofrequency ablation (RFA). @*Materials and Methods@#We retrospectively analyzed data collected from patients with saphenous vein incompetence who underwent either CAC or RFA at Seoul National University Hospital between November 2015 and December 2018. The stump lengths were measured using duplex ultrasonography (DUS) within 1 month and 6 months after treatment. The Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ) score were used to assess clinical outcomes. @*Results@#A total of 97 veins (64 great saphenous veins and 33 small saphenous veins) were analyzed. The stump length was not significantly different between the two groups at <1 month (P=0.311). However, the stump length in the CAC group was significantly longer than that in the RFA group at 6 months (P=0.004).At 6 months, the mean change in stump length was 1.41±2.28 cm in the CAC group and 0.51±0.54 cm in the RFA group (P=0.006). The VCSSs and AVVQ scores significantly improved after both procedures but were not significantly different between the two groups. @*Conclusion@#DUS at 6 months after treatment showed that the stump length in the CAC group increased more than that in the RFA group. No other factors affected the changes in stump length.

Better Efficacy of Balloon Assisted Maturation in Radial-Cephalic Arteriovenous Fistula for Hemodialysis

Purpose@#Native arteriovenous fistula (AVF) is the first choice for hemodialysis access; however, the maturation failure rate remains high. Hence, balloon-assisted maturation (BAM) is increasingly being used to overcome maturation failure. This study evaluated the outcomes of BAM and compared the differences between radial-cephalic (RC) and brachial-cephalic (BC) AVF. @*Materials and Methods@#Between January 2013 and December 2017, 1,622 new AVFs were created. BAM was considered if the AVF did not satisfy the criteria for hemodynamic maturation (6-mm diameter and 500-mL/min flow rate within 8 weeks after the operation). @*Results@#Of the 1,622 AVFs, BAM was performed in 142 patients (8.75%). There were 92 RC and 50 BC AVFs. Multivariate analyses revealed that ipsilateral central vein catheter history was the sole risk factor for maturation failure after BAM. Oneyear functional primary patency (FPP) and functional secondary patency (FSP) in RC AVFs were higher than those in BC AVFs without statistical significance (FPP, RC vs. BC: 70.9% vs. 50.9%, P=0.099; FSP, 95.5% vs. 81.1%, P=0.146). Further, based on the multivariate analysis, the independent risk factors for FPP in the RC and BC AVFs were the number of BAMs (odds ratio [OR], 3.05; 95% confidence interval [CI], 1.11-8.37; P=0.03) and age (OR, 1.04; 95% CI, 1.00-1.07; P=0.04), respectively. @*Conclusion@#BAM is a relatively good salvage method with tolerable patency. However, the risk factors for patency and the outcomes of BAM differ between RC and BC AVFs.

Do Not Tunnel the Small Bowel during the Tunneling of a Femoro-Femoral Bypass

A 62-year-old male with a history of femoro-femoral crossover bypass surgery 31 months previously presented with recurrent symptoms of fever and chills, along with a previous positive blood culture. Computed tomography showed vegetation in the bypass graft located in the peritoneal cavity, closely abutting the small bowel and soft tissue lesions in the right proximal thigh and distal calf. Under high suspicion of graft-enteric fistula with metastatic infection, surgery was performed to remove the previous graft and insert a new femoro-femoral bypass graft subcutaneously. Small bowel resection and anastomosis were also performed because the graft penetrated the small bowel mesentery and eroded into the small bowel.The patient had a patent graft without infection for more than 10 years. This case demonstrates the importance of tunneling in femoro-femoral crossover bypass free from the small bowel or other intraperitoneal organs.

Percutaneous Mechanical Thrombectomy of Submassive Pulmonary Embolism and Extensive Deep Venous Thrombosis for Early Thrombus Removal

Traditional treatment with anticoagulation in nonfatal submassive pulmonary embolism can result in serious sequelae of chronic thromboembolic pulmonary hypertension or poor exercise tolerance, and functional impairment. To prevent long-term complications in previously healthy young patients, other treatment options to actively resolve existing thrombi should be considered. Despite recommendations for use in only severe clinical presentations, endovascular interventional techniques could serve as suitable treatment options for such patients. Here we report the case of a previously healthy 23-year-old female with submassive pulmonary embolism and extensive deep vein thrombosis in the inferior vena cava down to the right popliteal vein. The patient was initially treated with catheterdirected thrombolysis. However, she continued to show extensive venous thrombosis and pulmonary embolism. Percutaneous thrombectomy and aspiration using an AngioJet successfully removed the main pulmonary artery embolism and venous thrombus. The patient’s recovery was uneventful, and 3-month follow-up showed no signs of recurrence or discomfort.

Directional Atherectomy for Treating In-Stent Restenosis of the Superficial Femoral Artery

Purpose@#The optimal treatment for in-stent restenosis (ISR) of the superficial femoral artery (SFA) is still in debate. This study aimed to evaluate the safety and effectiveness of directional atherectomy (DA) as a primary treatment modality for ISR in SFA. @*Materials and Methods@#A retrospective single-center analysis was conducted. In total, 617 stents were deployed in 242 limbs for SFA diseases during the study period. ISR was identified in 29 limbs (12.0%); 14 limbs were treated with DA and 15 limbs with balloon angioplasty (BAP) alone. Technical success rate, target lesion revascularization (TLR) and patency rates (PRs) at 12 months, and any complications were evaluated. @*Results@#DA group included complete occlusions in 50% of patients and BAP group included in 40%. Mean improvement in the ankle-brachial index was 0.29 and 0.32, respectively (P=0.638). Technical success was achieved in all patients.The procedural success rates were 85.7% and 73.3%, respectively (P=0.651). There was no significant difference regarding residual stenosis, distal embolization, or flow-limiting dissection. Primary PRs at 1 year were 85.7% and 73.3%, secondary PRs were 100.0% and 93.3%, and TLR rates were 14.3% and 20.0% (P=0.411, 0.326, and 0.684, respectively). @*Conclusion@#Short-term outcomes after DA for ISR were not different from those after BAP but showed a tendency of better primary PR and TLR. Larger multicenter prospective studies are needed to define the role of DA in ISR treatment.

Inconsistent Use of Terminology and Different Treatment Outcomes of Venous Adventitial Cystic Disease: A Proposal for Reporting Standards

Adventitial cystic disease (ACD) is a very rare condition characterized by the accumulation of a cyst filled with gelatinous substance in the adventitia of a vessel adjacent to the joint area. The cyst usually compresses the vessel lumen, causing claudication or leg swelling. The disease usually affects the popliteal artery. However, several cases of venous ACDs particularly in the common femoral or external iliac vein have been reported. The definition, diagnosis, and optimal treatment of ACD remain controversial because of its rarity and the inconsistent use of terminology. The heterogeneity of the reported cases is more prominent in venous ACD. Herein, the accurate terminology of cysts correlated to the joint (synovial cyst, ganglion cyst, and adventitial cyst) and the pathogenesis, anatomy, and optimal therapy of venous ACD are discussed in detail to establish reporting standards for future studies.

Predictive Value of Abnormal and Borderline Ankle-Brachial Index for Coronary Re-Intervention and Mortality in Patients with Coronary Artery Disease: An Observational Cohort Study

Purpose@#This study aimed to investigate the abnormal and borderline ABIs for predicting coronary re-intervention and mortality in patients with coronary artery disease (CAD). @*Materials and Methods@#Data from a previous study were obtained and used to investigate the prevalence of peripheral arterial disease among Korean patients with CAD (n=285) in 2010. All patients underwent follow-up coronary angiography as scheduled (asymptomatic: 2-, 5-, and 7-month intervals) or as clinically indicated (symptomatic). @*Results@#In total, 33 patients had an abnormal ABI (ab-ABI: 1.4), and 252 had a normal ABI (nl-ABI: 1.0≤ABI≤1.4). The mean follow-up was 47 months. The mortality was significantly higher in the ab-ABI group than in the nl-ABI group (18.2% vs. 6.7%, P=0.0233). MACEs were significantly more common in the ab-ABI group (60.6% vs. 34.5%, P=0. 0036). Moreover, the ab-ABI group had a greater CAD progression than the nl-ABI group (48.5% vs. 31.3%, P=0.0496). The incidence of clinically indicated coronary re-intervention was significantly higher in the ab-ABI group than in the nl-ABI group (33.3% vs. 13.1%, P=0.0025). After adjusting for age, diabetes, dyslipidemia, dialysis, smoking, and obesity, the incidence of clinically indicated re-intervention was significantly higher in the ab-ABI group than in the nl-ABI group (HR, 2.80; 95% CI, 1.24 to 6.34). @*Conclusion@#Abnormal and borderline ABI significantly increased the incidence of clinically indicated coronary revascularization and all-cause mortality during a 4-year follow-up among patients with CAD. Hence, ABI could be used to stratify extremely high-risk patients with CAD who may require aggressive surveillance or treatment.

Recanalization of an Occluded Vena Cava Filter and Iliac Veins with Kissing Stents to Treat Postthrombotic Syndrome with a Venous Stasis Ulcer

Inferior vena cava filters (IVCFs) are effective in preventing pulmonary embolism and their usage has rapidly increased over the past decades. However, complications have also significantly increased, as IVCF occlusion causes serious chronic venous insufficiency. Herein, we report a case of infrarenal IVCF occlusion that was successfully treated with the introduction of kissing stents through the IVCF into both iliac veins. A 54-year-old male presented with non-healing ulcers on his left leg. He had undergone IVCF implantation and warfarin medication due to deep vein thrombosis 4 years earlier in another hospital. Computed tomography (CT) revealed the filter-bearing IVC occlusion. Endovascular IVCF removal was attempted but failed. Kissing stents were deployed across the IVCF and extended into both iliac veins. Cone beam CT showed well-deployed stents just behind the occluded IVCF. Venous flow was restored without complications, and the recurrent ulcer healed immediately.

Thrombosis of a Long-Segment Aneurysm from the Iliac to Popliteal Artery Associated with Arteriovenous Malformation and Varicose Veins

A 58-year-old male patient with severe claudication due to thrombosis of the left ilio-femoro-popliteal artery aneurysm. He also had a venous stasis ulcer with a history of multiple embolotherapy of arteriovenous malformation. Duplex sonography revealed reflux and varicose veins of the left great saphenous vein (GSV). A sequential bypass surgery was performed that consisted of excision of the left external iliac and common femoral artery aneurysm, external iliac to deep femoral interposition with an expanded polytetrafluoroethylene graft, and femoro-posterior tibial artery bypass with the reversed left GSV. Symptoms of claudication were alleviated and the chronic ulcer was healed in time. To our knowledge, this is the first report of successful bypass in a patient with arterial aneurysm, arteriovenous malformation, and venous insufficiency that can be diagnosed as an atypical case of Parkes Weber syndrome. Long-term follow-up is needed to define the fate of aneurysms and varicose vein graft.

State-of-the-Art Strategies for the Vascularization of Three-Dimensional Engineered Organs

Engineering three-dimensional (3D) implantable tissue constructs is a promising strategy for replacing damaged or diseased tissues and organs with functional replacements. However, the efficient vascularization of new 3D organs is a major scientific and technical challenge since large tissue constructs or organs require a constant blood supply to survive in vivo. Current approaches to solving this problem generally fall into the following three major categories: (a) cell-based, (b) angiogenic factor-based, and (c) scaffold-based. In this review, we summarize state-of-the-art technologies that are used to develop complex, stable, and functional vasculature for engineered 3D tissue constructs and organs; additionally, we have suggested directions for future research.