Analysis of tip malposition and correction of peripherally inserted central catheters under ultrasound-guidance: 5-year outcomes from a single center

BACKGROUND

Peripherally inserted central catheter (PICC) has become a common procedure. Although ultrasound (US)-guidance has improved success rates, a small percentage of malposition is inevitable. The purpose of our study is to evaluate malposition rates of US-guided bedside PICC catheter insertion, and the clinical factors associated with malposition.

METHODS

This is a retrospective cohort study evaluating 5981 patients who had undergone ultrasound-guided bedside PICC placement from January 2017 to December 2021 at a single tertiary center. Final tip location was confirmed on chest radiograph.

RESULTS

Patients were categorized into optimal, suboptimal, and malposition groups according to final tip location. 4866 cases (81.7%) showed optimal tip position, 790 (13.3%) were suboptimal, and 299 (5.0%) were malpositioned. Logistic regression analysis identified six variables associated with tip malposition; height (odds ratio (OR) 1.044; 95% confidence interval (CI), 1.028-1.061; p < 0.001), body mass index (BMI) (OR 1.051; 95% CI, 1.017-1.087; p = 0.003), prior failure at accessing peripheral intravenous (IV) access (OR 1.718; 95% CI, 1.215-2.428; p = 0.002), side of the arm (OR 3.467; 95% CI, 2.457-4.891; p < 0.001), length of the catheter (OR 0.763; 95% CI, 0.734-0.794; p < 0.001), and number of previous central catheter insertions (OR 1.069; 95% CI, 1.004-1.140; p = 0.038). Malpositioned catheters were corrected by either bedside repositioning, bedside reinsertion, fluoroscopic reinsertion, switching to jugular catheters or catheter removal. No patient related factors were significantly associated with malposition or success of reposition.

CONCLUSION

US-guidance can help reduce catheter malposition during bedside PICC insertion. Patients with risk factors such as multiple previous central vein insertions, failed peripheral line insertions, left arm insertion, or high BMI should undergo thorough sonographic evaluation of the arm vessels to prevent malposition.

Development of in-vitro pulsatile flow generator for evaluating the performance of hemodialysis catheters

Hemodialysis (HD) using an HD catheter is performed widely on renal failure patients. The catheter was evaluated using the recirculation ratio in pre-clinical status, which is a crucial index indicating its performance. However, pre-clinical in-vivo experiments have limitations: high cost, and ethical issues. Hence, computational and in-vitro methods have been developed as alternatives. However, computational methods require fluid dynamic knowledge, whereas in-vitro experiments are complicated and expensive. In this study, we developed a pulsatile flow generator to mimic blood flow achieving cost effectiveness and user convenience. The device used iterative learning control, achieving blood flow in the superior and inferior vena cava within a 3.3% error. Furthermore, the recirculation ratios were measured based on two insertion directions and two different external pipe materials to evaluate the catheter regarding patients' posture and blood vessel stiffness. The results provide a better understanding of cardiovascular device performance without complicated and costly pre-clinical tests.

TcPO2 Value Can Predict Wound Healing Time in Clinical Practice of CLTI Patients

BACKGROUND

Transcutaneous oxygen pressure (TcPO2) is a noninvasive, nonradiological test to measure local oxygen released from capillaries through the skin. Since it reflects the metabolic state of the lower limb, it can predict wound healing in patients with critical limb threatening ischemia (CLTI). The purpose of this study was to determine the effectiveness of TcPO2 test in evaluating wound healing potential of patients with CLTI.

METHODS

This was a retrospective, single-center, nonrandomized, and observational study. A prospectively registered database of patients who visited Vascular Surgery Department of St. Mary's Hospital for CLTI and underwent TcPO2 tests from October 1, 2015 to July 1, 2021 was reviewed. Patients were divided into 2 groups: (1) those who had amputation only; and (2) those who underwent revascularization procedures. Patients whose wound healing status could not be determined were excluded. The clinical characteristics of patients, patient characteristics related to lower TcPO2 value, treatment success rate, and time for the wound to be healed were analyzed.

RESULTS

A total of 84 patients were included in this study. There was no difference in background patient characteristics between the 2 groups despite better survival within 12 months and shorter healing time in the revascularization group. A total of 76 patients survived 12 months after surgery, and 63 patients were healed. Higher HbA1c, higher serum creatinine, history of stroke, and history of coronary artery disease were related to lower TcPO2 value on multiple linear regression. The cutoff value of TcPO2 was determined to be 40 mm Hg for predicting wound healing. This value was similar to those of previous studies. In addition, there was a negative correlation between TcPO2 and wound healing time. Correlations among the anklebrachial index (ABI), toe-brachial index (TBI), and TcPO2 were not determined because ABI and TBI for some patients could not be obtained due to wound condition.

CONCLUSIONS

The TcPO2 value can predict the wound healing process of ischemic lower extremity injury.

Efficacy of blood flow measurement using intraoperative color flow Doppler ultrasound as a predictor of autologous arteriovenous fistula maturation

INTRODUCTION

Hemodialysis vascular access parameters of intraoperative Color flow Doppler ultrasound remain controversial. This study aimed to evaluate the optimal cut-off value and efficacy of intraoperative arteriovenous fistula parameters identified by Color flow Doppler ultrasound for arteriovenous fistula maturation success.

METHODS

This retrospective study consisted of a review of the medical records of 137 consecutive patients who underwent their first autologous arteriovenous fistula formation under local anesthesia for end-stage renal disease from April 9, 2020 to March 19, 2021.

RESULTS

The receiver operating characteristic curve analysis revealed that the optimal cut-off for intraoperative cephalic vein flow volume for brachiocephalic arteriovenous fistula maturation at the 4-week follow-up was 349.53 ml/min (area under the curve, 0.792; p, 0.036; Youden index, 0.514).

CONCLUSION

Intraoperative color Doppler ultrasound outflow cephalic vein flow volume is a useful factor in predicting arteriovenous fistula maturation. Intraoperative Color flow Doppler ultrasound should be performed.

Anatomical feasibility of fenestrated stent graft to treat complex abdominal aortic aneurysms from a Korean single institute database

Purpose

This study aims to investigate the feasibility of Zenith Fenestrated AAA Endovascular Graft (Z-FEN, Cook Medical) from a single Korean institution database by evaluating the vascular anatomy of Korean abdominal aortic aneurysm (AAA) patients with hostile aortic neck.

Methods

This is a retrospective study on patients with AAA who underwent endovascular aortic repair (EVAR) and open surgery repair between January 2012 and December 2021 (n = 211). The anatomic characteristics of the aortic neck were evaluated using 3-dimensional reconstructed computed tomographic scans. For the juxtarenal AAA patients (n = 39), feasibility of fenestrated stent graft was evaluated under the protocol of fenestrated EVAR. For those who were not suitable for the application of Z-FEN, the reasons for unsuitability were analyzed.

Results

Among 211 AAA patients, 108 patients (51.2%) had complex aortic neck, and 39 (18.5%) had insufficient aortic neck length (<15 mm) for conventional EVAR. Of the 39 patients with juxtarenal AAAs, 13 (33.3%) were determined feasible for Z-FEN. Twenty-six patients (66.7%) were noncandidate for Z-FEN due to severe neck angulation, short aortic neck length, inadequate iliac artery anatomy, large aortic neck diameter, and severe calcification and thrombosis. Proximal aortic neck length of the non-feasible group was significantly shorter than that of the feasible group (P = 0.002).

Conclusion

Z-FEN was applicable to 33.3% of the juxtarenal AAA patients. As recent studies confirm, the effectiveness and safety of fenestrated EVAR, Z-FEN can be an option for AAA patients with short aortic neck.

Preliminary outcomes of the LifeStream balloon-expandable stentgraft in Zenith Iliac branch device to preserve pelvic circulation: A Korean multicenter study

BACKGROUND

To evaluate early outcomes of aortoiliac or isolated iliac artery aneurysm repair using the Zenith® Bifurcated Iliac Side (ZBIS) stent graft combined with the LifeStream™ Balloon Expandable Vascular Covered Stent as a bridging stentgraft.

METHODS

Between August 2018 and February 2020, 38 patients (37 male, mean age 72.7 years) received 46 LifeStream stents in conjunction with 38 ZBIS stent grafts to bridge hypogastric arteries for aneurysm repair in six university hospitals in Korea. The primary outcomes were technical success rate and procedure-related complications. Secondary outcomes were bridging stent graft patency and re-intervention.

RESULTS

All procedures were performed as elective standard endovascular aortic aneurysm repair (EVAR) and unilateral iliac branch device (IBD). Mean follow-up was 13.1 months, and patient overall survival rate was 96.7%. Technical success rate was 76.3% (n = 29). Causes of failure included seven total endoleaks; six type Ic and one type IIIc from the IBD junction, one unintentional IIA coverage, and one failure to deploy the IIA stent graft. Procedure-related complications occurred in two patients: one LifeStream migration and one ZBIS stent graft migration. Overall patency rates for the LifeStream and ZBIS stents were 97.4% and 97.2%, respectively.

CONCLUSION

This multicenter preliminary experience with the LifeStream™ Balloon Expandable Vascular Covered Stent in IBD demonstrated good patency; however, an unexpectedly high rate of type Ic endoleaks was observed. Combined use of the LifeStream stent with the ZBIS stent graft is safe and feasible to preserve pelvic circulation with good patency and a low rate of device-related reintervention.

Application of venous thromboembolism prophylaxis program in patients with colorectal cancer using the enhanced recovery after surgery protocol

INTRODUCTION

The incidence of postoperative symptomatic venous thromboembolism (VTE) in western colorectal cancer is 1.1-2.5%. Anticoagulation and mechanical devices are recommended for moderate-to high-risk patients. Hospital stay and immobilization, as risk factors for VTE, are reduced by enhanced recovery after surgery (ERAS). This study aimed to evaluate short- and long-term outcomes for a VTE prophylaxis program after minimally invasive colorectal cancer surgery with ERAS protocol. In addition, predicting factors associated with VTE were investigated.

MATERIALS AND METHODS

We included 1043 patients diagnosed with colorectal cancer who required surgical treatment between January 2017 and December 2019 at a single institution. The patients enrolled followed the VTE prophylaxis program.

RESULTS

Five (0.5%) patients developed symptomatic VTE, and the median follow-up period was 21 months. The Caprini score for all VTE patients was ≤8 points; thus, only mechanical prophylaxis was applied. The incidence rate of postoperative symptomatic VTE was only 0.5%. There was no association between variables considered as associated with VTE onset, such as age, perioperative complication, and length of postoperative day. TNM staging (OR 2.44, 95% CI 1.4-4.16, p = 0.001) and the Caprini score (OR 1.75, 95% CI 1.1-2.8, p = 0.001) were associated with VTE onset.

CONCLUSION

Although pharmacological prophylaxis was only performed for Caprini scores ≥9, the VTE incidence rate of patients with colorectal cancer undergoing VTE prophylaxis program was 0.6%; 0.7% is the incidence criterion of the moderate group recommended for pharmacological prophylaxis. Continuous follow-up is required for patients with advanced-stage colorectal cancer with high-risk Caprini scores.

Successful ABO-incompatible living donor kidney transplantation in a recipient who developed flow cytometry crossmatch-positive donor-specific class I HLA antibodies following COVID-19 vaccination

The effects of COVID-19 vaccination on alloimmunization and clinical impact in transplant candidates remain largely unknown. In a 61-year-old man who had no donor-specific antibodies (DSA) and was planned to undergo ABO-incompatible kidney transplantation (ABOi KT), DSAs (anti-A24, anti-B51, anti-Cw14) developed after COVID-19 vaccination. After desensitization therapy, antibody level was further increased, leading to flow cytometric crossmatch-positive status. Donor-specific T cell immunity using interferon-gamma ELISPOT was continuously negative, whereas SARS-CoV-2 specific T cell immunity was intact. After confirming the C1q-negative status of DSA, the patient received ABOi KT. The patient had stable graft function and suppressed alloimmunity up to two months after KT. COVID-19 vaccination might relate to alloimmunization in transplant candidates, and desensitization through immune monitoring can help guide transplantation. This article is protected by copyright. All rights reserved.

Contrast enhanced duplex ultrasound for early postoperative follow-up after endovascular aneurysm repair: Relation to patient's initial risk of complications

OBJECTIVES

Current guidelines recommend initial postoperative follow-up with computed tomography angiography (CTA) after endovascular aneurysm repair (EVAR). However, CTA has risks associated with ionizing radiations and nephrotoxic contrast agents. We investigated possibilities to replace the initial postoperative CTA with contrast enhanced duplex ultrasound (CE-DUS) in selected patients.

METHODS

Out of the 273 consecutive patients who underwent EVAR, 173 were excluded and the 100 patients who underwent CTA and CE-DUS imaging concurrently (≤1 month interval between CTA and CE-DUS imaging) within 60 days after EVAR were analyzed. Patients who underwent EVAR outside the manufacturer's instructions for use or who had endoleaks discovered on intraoperative angiography were classified as the high-risk group, otherwise, they were classified as the low-risk group. Measurements of diagnostic values of CE-DUS ​​related to the detection of complications were calculated using CTA as the gold standard. McNemar's test was performed to compare these values and Pearson correlation coefficient was derived to compare CE-DUS measurements of sac diameters with CTA.

RESULTS

In the low-risk group, no difference was observed between CE-DUS and CTA in the detection of EVAR-related complications (sensitivity = 0.95, specificity = 0.93). In the high-risk group, CE-DUS was not as accurate as CTA for the detection of overall EVAR-related complications (sensitivity = 0.57, specificity = 0.86, p = 0.04) and for the detection of complications other than endoleaks (p = 0.02). Regarding sac diameter measurement, there was good agreement between CE-DUS and CTA (r = 0.92, p < 0.001).

CONCLUSIONS

First postoperative CE-DUS was reliable for the evaluation of EVAR-related complications compared to CTA in selected patients. Individualized EVAR follow-up strategy using CE-DUS based on the initial risk of EVAR-related complications should be considered.

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.

Effects of hypercholesterolism on expansion of abdominal aortic aneurysm in rat model

Background

Inflammation is recognized as a critical process in expansion of abdominal aortic aneurysm (AAA). A relationship between effects of cholesterol and statin in this process have been suggested, but remain untested. Therefore, current study aimed to examine the effects of hypercholesterolism on expansion of AAA in a rat model.

Methods

A total of 16 male rats were divided into 4 groups as follows: group I, normocholesterol diet and saline infusion, group II, normocholesterol diet and porcine pancreatic elastase (PPE) infusion, group III, hypercholesterol diet and PPE infusion, and group IV, hypercholesterol diet, PPE infusion and statin administration. At the 3rd week, saline was infused intraluminally in group I and PPE in groups II-IV to induce AAA. At the 5th week, blood and aortic tissue were obtained from each rat for evaluation of lipid profiles, aortic diameters (ADs), and characteristics of stains.

Results

Post-procedural aortic diameter (AD3) and AD3/pre-procedural aortic diameter (AD1) were significantly different among four groups (P = 0.042, P = 0.028, respectively). AD3 was significantly larger in group II than group I, and group III than group IV (P = 0.012, P = 0.043, respectively). AD3/AD1 was significantly higher in group II than group I, and group III than group II (P = 0.008, P = 0.030, respectively). Group III showed the highest cellularity for inflammatory cells.

Conclusions

Though larger experimental and clinical studies are necessary, authors suggest that hypercholesterolism can aggravate expansion of AAA, and that statin therapy can reduce it. Therefore, monitoring for hypercholesterolism and instituting statin therapy may be helpful to suppress expansion of AAA.

Retroperitoneal Viscum album extract instillation in patients with a large amount of drainage after kidney transplantation

Purpose

After kidney transplantation (KT), a large amount of drainage can delay postoperative recovery. Viscum album extract is an agent used in pleurodesis, and the purpose of this study was to evaluate the efficacy of this agent in reducing the amount of drainage after KT.

Methods

Medical records of patients with a large amount of drainage (≥ 100 mL/day) on postoperative day (POD) 7 after KT who had undergone V. album extract instillation through drainage tube (n = 115) or conservative management (n = 177) were retrospectively reviewed. The primary endpoint was a decrease in the amount of drainage on POD 14 from POD 7.

Results

A decrease in the amount of drainage on POD 14 from POD 7 was larger in the V. album extract instillation group than in the conservative management group (–228.3 ± 181.6 mL vs. –144.6 ± 202.0 mL, P < 0.001). Duration of hospitalization after operation was shorter in the V. album extract instillation group than in the conservative management group (15.9 ± 3.2 days vs. 18.1 ± 5.3 days, P < 0.001). In multivariate analysis, there was a statistically significant association of V. album extract instillation with lower risk of persistent large amount of drainage (≥ 100 mL/day on POD 14), with an odds ratio of 0.57 (95% confidence interval, 0.35–0.93; P = 0.026).

Conclusion

Retroperitoneal V. album extract instillation could be effective in reducing the amount of drainage and promoting postoperative recovery in patients with a large amount of drainage after KT.

Structural analysis of the dNTP triphosphohydrolase PA1124 from Pseudomonas aeruginosa

dNTP triphosphohydrolase (TPH) belongs to the histidine/aspartate (HD) superfamily and catalyzes the hydrolysis of dNTPs into 2'-deoxyribonucleoside and inorganic triphosphate. TPHs are required for cellular dNTP homeostasis and DNA replication fidelity and are employed as a host defense mechanism. PA1124 from the pathogenic Pseudomonas aeruginosa bacterium functions as a dGTP and dTTP triphosphohydrolase. To reveal how PA1124 drives dNTP hydrolysis and is regulated, we performed a structural study of PA1124. PA1124 assembles into a hexameric architecture as a trimer of dimers. Each monomer has an interdomain dent where a metal ion is coordinated by conserved histidine and aspartate residues. A structure-based comparative analysis suggests that PA1124 accommodates the dNTP substrate into the interdomain dent near the metal ion. Interestingly, PA1124 interacts with ssDNA, presumably as an allosteric regulator, using a positively charged intersubunit cleft that is generated via dimerization. Furthermore, our phylogenetic analysis highlights similar or distinct oligomerization profiles across the TPH family.

Identification of a Novel Antigen for Serological Diagnosis of Scrub Typhus

Scrub typhus is an acute infectious disease caused by the bacterium Orientia tsutsugamushi, which is widely distributed in northern, southern, and eastern Asia. Early diagnosis is essential because the average case fatality rate is usually >10% but can be as high as 45% if antimicrobial treatment is delayed. Although an O. tsutsugamushi 56-kDa type-specific antigen (TSA) is commonly used for serological diagnosis of scrub typhus, the 56-kDa TSA shows variations among O. tsutsugamushi strains, which may lead to poor diagnostic results. Therefore, the discovery of new antigenic proteins may improve diagnostic accuracy. In this study, we identified an O. tsutsugamushi 27 kDa antigen through an immunoinformatic approach and verified its diagnostic potential using patient samples. Compared with the O. tsutsugamushi 56-kDa antigen, the new 27-kDa antigen showed better diagnostic specificity with similar diagnostic sensitivity. Therefore, the O. tsutsugamushi 27-kDa antigen shows potential as a novel serological diagnostic antigen for scrub typhus, providing higher diagnostic accuracy for O. tsutsugamushi than the 56-kDa antigen.

Changes in hemostatic factors after kidney transplantation: A retrospective cohort study

Chronic kidney disease affects hemostasis in complex ways, producing both thrombotic and hemorrhagic diatheses. These changes may impact patient morbidity and mortality pre-transplantation, as well as allograft survival after kidney transplantation (KT). This study was conducted to analyze changes in hemostatic factors in the early post-KT period.We retrospectively analyzed 676 recipients of kidney allografts from December 2009 to December 2014. Patients receiving plasmapheresis pre- or post-KT, experiencing early allograft failure, or receiving anticoagulants or antiplatelet agents pre- or post-KT were excluded.Of the 367 included patients, acute (≤1 month) rejection occurred in 4.1% and delayed graft function occurred in 3.3%. Postoperative bleeding complications occurred in 7.9% of patients and thrombotic complications in 3.3%. Pre-transplantation, recipients had below normal hemoglobin, above normal d-dimer and homocysteine levels, and elevated rates of antiphospholipid antibodies. Hemoglobin increased to almost normal by postoperative day (POD) 28 (P  < .001). d-dimer increased on POD7, 14, and 28, although the values were not significantly different from pre-KT. The pattern of d-dimer changes suggested that they were a nonspecific consequence of major surgery. Homocysteine decreased to normal by POD7 (P  < .001). The percentage of patients with ≥1 prothrombotic factor was 82.0% pre-KT and only 14.2% on POD28 (P  < .001).The most of patients exhibited prothrombotic tendencies, including increased d-dimer and homocysteine, and increased prevalence of antiphospholipid antibodies before transplantation. They also had pre-transplantation anemia, suggesting a concomitant bleeding diathesis. However, most of these abnormal hemostatic factors improved or resolved after KT.

Efficacy of Lymphatic Sealing Using the LigaSure in Kidney Transplantation: A Pilot Study

BACKGROUND

Iliac vessel lymphatic ligation is critical in kidney transplantation, because it is associated with the occurrence of lymphocele. Lymphocele can also affect the renal graft. This study aimed to evaluate the efficacy of lymphatic sealing using LigaSure (an electrothermal bipolar sealing device) in kidney transplantation as compared with conventional silk-tie ligation.

METHODS

This retrospective study included 100 consecutive patients from a prospectively registered database who underwent kidney transplantation at Seoul St. Mary's Hospital, South Korea, between December 1, 2019 and November 12, 2020. Comorbidities, primary renal disease, transplantation variables, surgical variables, and posttransplantation outcomes were compared between conventional and LigaSure lymphatic ligations. Subgroup analyses were performed by anastomosis pattern.

RESULTS

The mean age of patients was 47.4 ± 12.40 (range, 24-73) years. The LigaSure and conventional groups comprised 50 (50%) patients. Hypertension history, number of anastomosed renal arteries, and anastomosis patterns differed significantly between groups (P < .05). No significant difference was found in postoperative outcomes. In the subgroup analysis, greater drain volume was found at postoperative day 1 in the end-to-end internal iliac artery-renal artery anastomosis group (P = .001) because the internal iliac artery dissection results in longer lymphatic ligation. Nevertheless, no differences in drain removal time (P = .528) or lymphocele incidence were found between subgroups.

CONCLUSION

LigaSure is expected to benefit from surgery time and will be identified in subsequent studies. LigaSure can be safely and comfortably used for iliac lymphatic ligation in kidney transplantation. In conclusion, LigaSure lymphatic ligation is superior to conventional lymphatic ligation in kidney transplantation.

Endovascular treatment for transplant renal artery stenosis: A retrospective cohort study

Transplant renal artery stenosis (TRAS) is the most common (1%-23%) vascular complication following kidney transplantation. The aim of this study was to review our experience with an endovascular approach to treat TRAS.We retrospectively reviewed kidney transplant recipients who underwent percutaneous transluminal angioplasty (PTA) due to TRAS in our institute from January 2009 to December 2015. We analyzed the patient's baseline characteristics, postoperative renal function, blood pressure evolution, and the number of pre- and post-procedure antihypertensive drugs.A total of 21 patients (15 men, 6 women) were treated with the endovascular technique. The predominant presentation was graft dysfunction (76.2%). Stenosis or hemodynamic kinking was located at the anastomosis in 7 (33.3%) patients, proximal to the anastomosis in 13 (61.9%) patients, and distal the anastomosis in 1 (4.8%) patient. PTA without stent placement was performed in 7 patients (33.3%), and PTA with stent placement was performed in 14 patients (67.7%). Serum creatinine levels demonstrated no difference between the pre-procedure level and that on discharge day (1.61 mg/dl [0.47-3.29 mg/dl] vs 1.46 mg/dl [0.47-3.08 mg/dl]; P = .33). The glomerular filtration rate also showed no difference between the pre-procedure value and that on discharge day (53.6 ml/min [22.4-145.7 ml/min] vs 57.0 ml/min [17.56 -145 ml/min]; P = .084). Systolic blood pressure and diastolic blood pressure (DBP) varied from 137 mm Hg (120-160 mm Hg) and 84 mm Hg (70-100 mm Hg) pre-procedure to 129 mm Hg (90-150 mm Hg) and 79 mm Hg (60-90 mm Hg) at discharge, respectively (P = .124 and P = .07). The number of antihypertensive medications significantly decreased from 1.5 (0-6) pre-procedure to 0.5 (0-2) at discharge (P = .023). In our study, there were no technical failures, procedure-related complications or deaths. During the follow-up period, the free-from-reintervention rate was 100%, and graft failures occurred in 2 patients (9.5%) due to rejection.Endovascular procedures for TRAS show a high technical success rate with a low complication rate and a low reintervention rate. PTA showed a trend toward a positive impact on lowering serum creatinine, systolic blood pressure, and diastolic blood pressure and improving estimated glomerular filtration rate, and the number of antihypertensive medications could be significantly reduced after this procedure.

Development of New Hemodialysis Catheter Using Numerical Analysis and Experiments

A hemodialysis (HD) catheter, especially one with a symmetric tip design, plays an important role in the long-term treatment of patients with renal failure. It is well known that the design of the HD catheter has a considerable effect on blood recirculation and thrombus formation around it, which may cause inefficiencies or malfunctions during HD. However, hemodynamic analyses through parametric studies of its designs have been rarely performed; moreover, only comparisons between the existing models have been reported. In this study, we numerically analyzed the design of the HD catheter's side hole and distal tip for evaluating their effects on hemodynamic factors such as recirculation rate (RR), shear stress, and blood damage index (BDI). The results indicated that a larger side hole and a nozzle-shaped distal tip can significantly reduce the RR and shear stress around the HD catheter. Furthermore, based on these hemodynamic insights, we proposed three new HD catheter designs and compared their performances with existing catheters using numerical and in vitro methods. These new designs exhibited lower RRs and BDI values, thus providing better performance than the existing models. These results can help toward commercialization of more efficient HD catheters.

Relationships between metabolic syndrome and aspects of abdominal aortic aneurysm

BACKGROUND

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities strongly associated with risks of cardiovascular diseases. However, a relationship between MetS and aneurysmal disease as compared with occlusive disease has not been confirmed. Therefore, correlations of MetS and abdominal aortic aneurysm (AAA) were evaluated.

METHODS

Between March 2011 and February 2020, 354 patients diagnosed with AAA were enrolled and divided into the MetS (n = 164) and the no-MetS (n = 190) groups. Individual components of MetS, characteristics of AAA, rupture rate, and survival rate were evaluated for both groups. Additionally, correlations between MetS and AAA were evaluated with focusing on effects of diabetes mellitus (DM).

RESULTS

The size of AAA was significantly larger in the MetS group compared with the no-MetS group (P < 0.05). The rupture rate was significantly higher in the MetS group compared with the no-MetS group (P < 0.05) and the survival rate was significantly higher in the no-MetS group (P < 0.05). In terms of DM, the size of AAA was significantly larger in the no-DM group compared with the DM group (P < 0.05). MetS was significantly more prevalent in the DM group compared with the no-DM group (P < 0.05). Finally, the rupture and survival rates were not statistically different between the DM and the no-DM groups (P > 0.05).

CONCLUSIONS

Although larger prospective studies are necessary, we suggest that MetS proportionally aggravates the status of AAA and survival rate. Therefore, surveillance for MetS and individual components may help to restrict the expansion of AAA.

Acute allograft dysfunction mimicking thrombotic microangiopathy in kidney transplant recipient with renal infarction: case report and review of literatures

Acute allograft dysfunction is rarely observed in kidney transplantation (KT). We report an unusual case of acute allograft dysfunction mimicking thrombotic microangiopathy (TMA) in recipient with renal infarction. A 65-year-old man underwent KT from his 39-year-old son. Pre-transplant donor evaluation was normal except for the branches of the upper and lower pole renal arteries originating from the aorta in renal computed topographic angiography, respectively. The immediate post-transplant clinical course was uneventful, but serum creatinine (SCr) increased from 2.2 to 4.5 mg/dL, anemia and thrombocytopenia were shown, and serum lactate dehydrogenase increased to 919 U/L on the third day after transplantation. We suspected TMA, because of no evidence of acute bleeding. The laboratory parameters associated with TMA were within normal ranges. Renal magnetic resonance angiography revealed a focal wedge-shaped perfusion defect in the upper pole of the graft and renal Doppler ultrasonography showed decreased perfusion of the lower pole of the graft. Graft function improved with conservative therapy. The patient was discharged with SCr of 1.21 mg/dL. Graft function has been stable after discharge. Acute allograft infarction should be considered in the differential diagnosis of acute allograft dysfunction mimicking TMA in recipients with grafts supplied by multiple renal arteries.

Activation of the Legionella pneumophila LegK7 Effector Kinase by the Host MOB1 Protein

Legionella pneumophila infects alveolar macrophages and can cause life-threatening pneumonia in humans. Upon internalization into the host cell, L. pneumophila injects numerous effector proteins into the host cytoplasm as a part of its pathogenesis. LegK7 is an effector kinase of L. pneumophila that functionally mimics the eukaryotic Mst kinase and phosphorylates the host MOB1 protein to exploit the Hippo pathway. To elucidate the LegK7 activation mechanism, we determined the apo structure of LegK7 in an inactive form and performed a comparative analysis of LegK7 structures. LegK7 is a non-RD kinase that contains an activation segment that is ordered, irrespective of stimulation, through a unique β-hairpin-containing segment, and it does not require phosphorylation of the activation segment for activation. Instead, bacterial LegK7 becomes an active kinase via its heterologous molecular interaction with the host MOB1 protein. MOB1 binding triggers reorientation of the two lobes of the kinase domain, as well as a structural change in the interlobe hinge region in LegK7, consequently reshaping the LegK7 structure into an ATP binding-compatible closed conformation. Furthermore, we reveal that LegK7 is an atypical kinase that contains an N-terminal capping domain and a hydrophilic interlobe linker motif, which play key roles in the MOB1-induced activation of LegK7.

Development of a SARS-CoV-2-specific biosensor for antigen detection using scFv-Fc fusion proteins

Coronavirus disease 2019 (COVID-19) is a newly emerged human infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In a global pandemic, development of a cheap, rapid, accurate, and easy-to-use diagnostic test is necessary if we are to mount an immediate response to this emerging threat. Here, we report the development of a specific lateral flow immunoassay (LFIA)-based biosensor for COVID-19. We used phage display technology to generate four SARS-CoV-2 nucleocapsid protein (NP)-specific single-chain variable fragment-crystallizable fragment (scFv-Fc) fusion antibodies. The scFv-Fc antibodies bind specifically and with high affinity to the SARS-CoV-2 NP antigen, but not to NPs of other coronaviruses. Using these scFv-Fc antibodies, we screened three diagnostic antibody pairs for use on a cellulose nanobead (CNB)-based LFIA platform. The detection limits of the best scFv-Fc antibody pair, 12H1 as the capture probe and 12H8 as the CNB-conjugated detection probe, were 2 ng antigen protein and 2.5 × 10⁴ pfu cultured virus. This LFIA platform detected only SARS-CoV-2 NP, not NPs from MERS-CoV, SARS-CoV, or influenza H1N1. Thus, we have successfully developed a SARS-CoV-2 NP-specific rapid diagnostic test, which is expected to be a simple and rapid diagnostic test for COVID-19.

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SARS-CoV-2 NP-specific scFv-Fc antibodies were generated.

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Antibody pairs for the specific and sensitive detection of SARS-CoV-2 were found.

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Lateral flow immunoassay-based rapid diagnostic tests sensitively detected NP antigen and SARS-CoV-2 virus.

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The COVID-19 biosensor showed no cross-reactivity with other coronaviruses, SARS-CoV and MERS-CoV.

Apo structure of the transcriptional regulator PadR from Bacillus subtilis: Structural dynamics and conserved Y70 residue

PadR is a bacterial transcriptional regulator that controls the expression of phenolic acid decarboxylase (PadC) in response to phenolic acids to prevent their toxic effects. During transcriptional repression, PadR associates with the operator sequence at the promoter site of the padC gene. However, when phenolic acids are present, PadR directly binds the phenolic acids and undergoes an interdomain rearrangement to dissociate from the operator DNA. To further examine the structural dynamics of PadR, we determined the apo structure of Bacillus subtilis PadR. Apo-PadR exhibits significant interdomain flexibility and adopts structures that are similar to the phenolic acid-bound PadR structures but distinct from the DNA-bound structure, suggesting that apo-PadR can bind phenolic acids without substantial structural rearrangement. Furthermore, we identified the Y70 residue of PadR as the most conserved residue in the PadR family. PadR Y70 displays similar conformations irrespective of the associated partners, and its conformation is conserved in diverse PadR family members. The Y70 residue is surrounded by the key DNA-binding entities of PadR and is required to optimally arrange them for operator DNA recognition by PadR. PadR Y70 also plays a critical role in protein stability based on the results of a denaturation assay. These observations suggest that PadR Y70 is a canonical residue of the PadR family that contributes to protein stability and DNA binding.

Long-term mortality of patients with tuberculosis in Korea

BACKGROUND: Long-term mortality following tuberculosis (TB) diagnosis in Korea remains unclear.METHODS: The present study used data from the National Health Insurance Service database, an extensive health-related database including most Korean residents. TB patients were identified using International Classification of Diseases, Tenth Revision coding (A15-19, U88.0-88.1) and the type of anti-TB drug(s) between 2003 and 2016. Long-term mortality and causes of death in TB patients were analysed.RESULTS: A total of 357 211 individuals had TB over the period from 2003 to 2016 and 103 682 died. The mean age of the cohort was 54.7 ± 20.7 years, and 59.8% were male. The survival probability of TB patients at 1, 5, and 10 years after diagnosis was 87.8%, 75.3%, and 63.3%, respectively. High mortality and TB-related death rates were especially prominent in the early stages after TB diagnosis. The overall standardized mortality ratio of TB patients to the general Korean population was 3.23 (95% confidence interval 3.21-3.25).CONCLUSION: Mortality in TB patients was especially high in the early stages of disease after TB diagnosis, and mostly due to TB. This figure was approximately three-times higher than the mortality rate in the general population.

Successful kidney transplantation from an expanded criteria donor with long-term extracorporeal membrane oxygenation treatment: A case report

BACKGROUND

Due to a shortage of donor kidneys, many centers have utilized graft kidneys from brain-dead donors with expanded criteria. Kidney transplantation (KT) from donors on extracorporeal membrane oxygenation (ECMO) has been identified as a successful way of expanding donor pools. However, there are currently no guidelines or recommendations that guarantee successful KT from donors undergoing ECMO treatment. Therefore, acceptance of appropriate allografts from those donors is solely based on clinician decision.

CASE SUMMARY

We report a case of successful KT from a brain-dead donor supported by ECMO for the longest duration to date. A 69-year-old male received a KT from a 63-year-old brain-dead donor who had been on therapeutic ECMO treatment for the previous three weeks. The recipient experienced slow recovery of graft function after surgery but was discharged home on post-operative day 17 free from hemodialysis. Allograft function gradually improved thereafter and was comparatively acceptable up to the 12 mo follow-up, with serum creatinine level of 1.67 mg/dL.

CONCLUSION

This case suggests that donation even after long-term ECMO treatment could provide successful KT to suitable candidates.

Changing pattern and safety of pretransplant malignancy in kidney transplant recipients

Background

Cancer rates are increasing not only in the general population but also in patients with end-stage renal disease. We investigated the changing pattern of pretransplant malignancy in kidney transplant recipients over 5 decades.

Methods

We reviewed 3,748 kidney transplant recipients between 1969 and 2016. We divided patients into three groups (1969-1998, 1999-2006, 2007-2016) based on the era of the cancer screening system used throughout the nation. We analyzed the incidence and pattern of pretransplant malignancy among the three groups. We also evaluated recurrent and de novo malignancy in these patients compared to patients without pretransplant malignancy.

Results

A total of 72 patients exhibited pretransplant malignancy (1.9%). There were no cases of pretransplant cancer until 1998, but the rate of pretransplant malignancy gradually increased to 1.1% during 1999-2006 and further increased to 4.3% thereafter. The most frequent types of pretransplant malignancy changed from the bladder, liver, and stomach cancers to thyroid cancer and renal cell carcinoma. There were no de novo cases, but there were three cases of recurrent cancer in patients with pretransplant malignancy; the recurrence rate among kidney transplant recipients with pretransplant malignancy was not significantly different from the incidence rate of de novo malignancy among kidney transplant recipients without pretransplant malignancy (4.2% vs. 6.9%, P = 0.48).

Conclusion

The incidence of pretransplant malignancy in kidney transplantation candidates is gradually increasing, and recent increases were accompanied by changes in cancer types. Pretransplant malignancy may not be a hindrance to kidney transplantation because of the low incidence of posttransplant recurrence and de novo malignancy.

A Half-Century 3000 Cases of Kidney Transplant Experiences in a Single Hospital: the Longest Registry in Korea

BACKGROUND

This study aims to analyze the entire registry of kidney transplant over the past 50 years and understand the clinical significance.

METHODS

From the data on 3012 kidney transplants performed at our center between March 1969 and September 2018, we analyzed retrospectively clinical variables.

RESULTS

Until September 2018, there have been 3012 kidney transplants performed. The number of primary transplant cases was 2755 (91.8%), which included 16 cases of simultaneous liver-kidney transplant, and the number of repeated transplants was 245 (225 second transplants [7.5%] and 20 third transplants [0.7%]). There were 3 simultaneous pancreas kidney transplants, and 3 small bowel-kidney transplants, one of them being transplanted at the same time. There was a single simultaneous heart-kidney transplant. The viability rates of a transplanted kidney for 1, 5, 10, 20, and 30 years were 97%, 92%, 90%, 51%, and 36%, respectively, and the patient survival rates were 96%, 89%, 82%, 64%, and 52%, respectively. Five-year graft survival rate of the first 1000 cases was 64.6%; those of the 1001st to 2000th cases and 2001^st to 3012th cases were 87.6% and 88.8%, respectively. There are statistically significant differences among the groups.

CONCLUSION

This study has identified the appropriate selection or control of immunotherapy, based on the risk level of kidney transplant recipient, is needed to minimize chronic rejection, which is the key cause of transplanted kidney failure.

Surgical removal of an inferior vena cava filter with duodenal penetration

Complications due to long-term implantation of inferior vena cava (IVC) filters have increased. Among these, IVC wall penetration by struts can lead to penetration of adjacent structures, which can be fatal to the patient. Herein, we report a case of a 63-year-old woman who underwent surgical removal of an IVC filter with duodenal penetration. Oesophagogastroduodenoscopy findings revealed a strut in the duodenal second portion. The IVC filter was inserted 19 months ago but had not been retrieved. On admission, computed tomography showed malposition of the IVC filter with penetration of duodenum by an anterior strut. Therefore, we performed surgical removal of the IVC filter. After surgery, her postoperative course was uneventful.

Long-Term Outcomes of Renal Function After Adult Intestinal Transplantation at a Single Small-Volume Center: 2 Cases of Renal Transplantation

PURPOSE

Renal dysfunction more frequently occurs after intestinal transplantation (ITx) than after heart, lung, or liver transplantation. We provide a clinical analysis of renal function after adult ITx.

METHODS

We retrospectively analyzed 8 adult ITx patients who survived for at least 6 months between 2004 and 2018. Glomerular filtration rate (GFR) measurements were performed at baseline, at 3 and 6 months post-transplantation, and yearly. The median follow-up duration was 53.5 months.

RESULTS

All cases were isolated ITx; 3 received living-donor ITx, and 5 received deceased-donor ITx. The mean baseline GFR was 97 mL/min/1.73 m². The GFR had decreased by more than 50% of baseline at 1 year post-transplant. Renal dysfunction was observed in 4 patients. Two patients developed acute kidney injury due to acute rejection and sepsis. One of these patients fully recovered renal function, but the second patient died. Another 2 patients developed chronic kidney disease and required hemodialysis (HD) within 6 and 3 years, respectively. The first living-donor ITx patient lost renal function progressively over 6 years after ITx. She received a renal graft from the same living donor as for the ITx after 3 years of HD. The other patient (deceased-donor ITx) received a kidney from his daughter at 5 months after HD.

CONCLUSIONS

To obtain an accurate assessment of renal function, frequent direct measurements of GFR should be performed to facilitate early diagnosis of renal impairment and to determine subsequent strategies to improve renal function after ITx.

Antioxidant, antibacterial, and anti-adhesive activities of biosurfactants isolated from Bacillus strains

Biosurfactants are surface-active compounds that display a range of physiological functions. The present study investigated the antioxidant, antimicrobial, and anti-adhesive or anti-biofilm potential of biosurfactants isolated from Bacillus subtilis VSG4 and Bacillus licheniformis VS16. The antioxidant activity of the biosurfactants was studied in vitro using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. At 5 mg/mL of the biosurfactant concentration, the scavenging of DPPH and hydroxyl radicals was found to be between 69.1-73.5% and 63.3-69.8%, respectively. The biosurfactants also displayed significant antibacterial activities against both Gram-positive and Gram-negative bacteria. The anti-adhesive activities of the biosurfactants were evaluated against Staphylococcus aureus ATCC 29523, Salmonella typhimurium ATCC 19430, and Bacillus cereus ATCC 11778. The biosurfactants exhibited anti-adhesive activity, even at concentrations of 3-5 mg/mL. Moreover, both biosurfactants displayed notable anti-biofilm activities with a biofilm eradication percentage ranging from 63.9 to 80.03% for VSG4 biosurfactant, and from 61.1-68.4% for VS16 biosurfactant. Furthermore, VSG4 biosurfactant exhibited emulsification and surface tension stability over a wide range of pH (4-10) and temperature up to 100 °C. These results show that VSG4 and VS16 biosurfactants can be potentially used as natural antioxidants, antimicrobials, and/or anti-adhesive agents for food and biomedical applications.

Analysis of Pre-transplant Resuscitation Factors Influencing Immediate Graft Function After Deceased Donor Kidney Transplantation

BACKGROUND

The management of a deceased donor in the intensive care unit before organ transplantation is important for the outcome of the recipient. Herein, we analyze the pre-transplant resuscitation factors managed before procurement that could influence graft function immediately after deceased-donor kidney transplantation (DDKT).

METHODS

A total of 271 DDKTs performed at Seoul St. Mary's Hospital, Korea, from January 2009 to March 2016 were reviewed. We divided the patients into a delayed graft function (DGF) group and a non-DGF group, and compared postoperative outcomes between the 2 groups. We also analyzed the predisposing factors of DGF using multivariate analysis.

RESULTS

A total of 36 cases developed DGF while 235 patients did not, and the demographic characteristics of the recipients in the two groups had no significant difference. Of the pre-transplant resuscitation factors, preoperative polyuria, the maximal levels of serum sodium and BUN, and transfer times were significantly higher in the DGF group (P < .001). In a multivariable analysis, preoperative polyuria (odds ratio 4.835, P = .036), elevated preoperative level of sodium (odds ratio 1.227, P = .001), and extended transfer times (odds ratio 1.001, P < .001) were the independent risk factors of the donor in pre-transplant resuscitation management associated with DGF.

CONCLUSIONS

Polyuria, high levels of sodium before procurement, and prolonged transfer times are independent risk factors for DGF after a DDKT. Active intervention and early implementation of the intensivist can help in managing these factors effectively and thus ultimately improve graft function.

Kidney transplantation using expanded criteria deceased donors with terminal acute kidney injury: a single center experience in Korea

Purpose

We investigated the clinical outcomes of deceased donor kidney transplantation (KT) using kidneys with terminal acute kidney injury (AKI).

Methods

Between February 2000 and December 2013, we performed 202 deceased donor renal transplants from 159 brain dead donors. According to the expanded criteria donor (ECD) and AKI network criteria, we divided 202 recipients into 4 groups: Group I: Non-AKI & standard criteria donor (SCD) (n = 97); group II: Non-AKI & ECD (n = 15); group III: AKI & SCD (n = 52); and group IV: AKI & ECD (n = 38).

Results

The incidence of delayed graft function (DFG) was significantly higher in patients with AKI than it was in the non-AKI group (P = 0.008). There were no significant differences among the 4 groups in graft survival (P = 0.074) or patient survival (P = 0.090). However, the long-term allograft survival rate was significantly lower in group IV than it was in other groups (P = 0.024).

Conclusion

Allografts from deceased donors with terminal AKI had a higher incidence of DGF than did those from donors without AKI. However, there is no significant difference in graft and patient survival rates among the groups. So, the utilization of renal grafts from ECDs with terminal AKI is a feasible approach to address the critical organ shortage.