Conservative fluid resuscitation protocol does not reduce the incidence of reoperation for bleeding after emergency CABG.

Reoperation for bleeding (ROB) after emergency coronary artery bypass grafting (eCABG) has been identified as an independent risk factor for mortality. Consecutively, the influence of fluid intake, fluid output, fluid balance, blood loss, and inotropic demand on ROB were analyzed. This retrospective single-center study included 265 patients undergoing eCABG between 2011 and 2020. From 2018, postoperative hemodynamic management was performed with lower volume administration and higher vasoactive support. The primary outcome measure was the incidence of ROB within 48 h according to altered fluid resuscitation strategy. Consecutively, the influence of fluid intake, fluid output, fluid balance, blood loss, and inotropic demand on ROB were analyzed. Incidence of ROB was independent from the volume resuscitation protocol (P = .3). The ROB group had a higher perioperative risk, which was observed in EuroSCORE II. Fluid intake (P = .021), fluid balance (P = .001), and norepinephrine administration (P = .004) were associated with ROB. Fluid output and blood loss were not associated with ROB (P = .22). Post-test probability was low among all variables. Although fluid management might have an impact on specific postoperative complications, different fluid resuscitation protocols did not alter the incidence of ROB after emergency CABG. TRIAL REGISTRATION: www. CLINICALTRIALS: gov registration number NCT04533698; date of registration: August 31, 2020 (retrospectively registered due to nature of the study); URL: https://classic. CLINICALTRIALS: gov/ct2/show/NCT04533698.

Prediction of immediate bleeding after cold snare polypectomy: A prospective observational study.

The risk factors for immediate post-polypectomy bleeding (IPPB) after cold snare polypectomy (CSP) are not well-known. We sought to define such risk factors and develop a predictive risk-scoring model. This prospective observational study included 161 polyps (4-9 mm in diameter) that were removed via CSP from 118 patients during the period from June to September 2019 in 2 tertiary hospitals. IPPB was defined as post-polypectomy bleeding within 24 hours or grade 3 or 4 intraprocedural bleeding requiring endoscopic hemostasis. IPPB incidences according to grade were 13.0% (21/161) (grade 3) and 0% (grade 4). Univariate analysis showed that the polyp size and morphology, as well as iatrogenic ulcer size and shape, were significantly associated with IPPB. Multivariate analysis showed that polyp size [6-9 mm vs 4-5 mm, odds ratio (OR) 3.72, 95% confidence interval (CI) 1.28-10.79], polyp morphology (polypoid vs non-polypoid, OR: 3.93, 95% CI: 1.22-12.64), and iatrogenic ulcer size (≥10 vs ≤ 9 mm, OR: 3.12, 95% CI: 1.04-9.38) were significantly associated with IPPB. We created a four-marker risk-scoring model to predict IPPB after CSP; we summed the points assigned for the 4 factors. At a cutoff of 2, the sensitivity was 85.7% and the specificity was 65.0%; at a cutoff of 3, the sensitivity was 65% and the specificity was 90.0%. Polyp size and morphology, as well as iatrogenic ulcer size and shape, were associated with IPPB after CSP. The four-marker risk-scoring model appears to effectively predict IPPB after CSP (Clinical Research Information Service: KCT0004375).

Postoperative bleeding complications in breast conserving surgery and the role of antithrombotic medications: retrospective analysis of 4712 operations.

BACKGROUND: This study aimed to evaluate the risk and timing of postoperative bleeding complications following breast-conserving surgery (BCS), with or without axillary surgery, especially in relation to perioperative management of antithrombotic medications. METHODS: Data from all patients who underwent BCS for breast cancer between 2010 and 2022 at a single university hospital were collected. Medical records were reviewed for reoperations, unplanned admissions, and patient characteristics. RESULTS: In total, 4712 breast-conserving surgeries and 3631 axillary surgeries were performed on 3838 patients. The risk of any bleeding complication was 1.1% (40/3571) in breast-conserving surgery, 0.3% (9/2847) in sentinel lymph node biopsy, and 0.5% (4/779) in axillary lymph node dissection. Upon arrival for treatment, 645 (17%) patients were taking antithrombotic medications. The risk of bleeding complications was not elevated in patients whose medication was discontinued at least a day before the surgery (OR 0.84, p = 0.76); but it was almost four-fold (OR 3.61, p = 0.026) in patients whose antithrombotic medication was continued. However, the absolute risk for bleeding complication was low in these patients as well (2.0%, 15/751). The majority of bleeding complications (85%, 47/55) occurred within 24 h after the surgery. CONCLUSION: The risk for bleeding complications was elevated, but still low, after BCS with or without axillary surgery, when antithrombotic medications were continued through the surgical period. Discontinuing antithrombotic medications is not obligatory in these patients.

Application of the pancreatic body suspension technique in laparoscopic splenectomy combined with selective pericardial varicosity dissection: An observational study.

To investigate the safety of pancreatic body suspension (PBS) technique in laparoscopic splenectomy combined with pericardial devascularization for patients. A retrospective study inclusive of 16 patients who underwent laparoscopic splenectomy combined with pericardial devascularization from 2017 to 2022 was performed. A total of 5 patients underwent PBS technique and 11 underwent the traditional technique. There was no significant difference in age, sex, body mass index (BMI), preoperative serum white cell count (WBC), platelets (PLT), hemoglobin (HB), albumin (ALB), prothrombin time (PT), total bilirubin (TBIL), or spleen size between the 2 groups (P > .05). In the PBS group, the operation time was 280 minutes. The estimated intraoperative blood loss (EBL) was 250 mL. The mean postoperative hospitalization length was 11.2 days. There was no conversion to an open procedure or postoperative bleeding. In the traditional method group, the mean operation time was 240.91 minutes. The EBL was 290.91 mL. There were 2 cases of conversion to open, 3 cases of postoperative bleeding, and 1 reoperation. The incidence of postoperative short-term complications (postoperative bleeding, reoperation) was significantly higher in the traditional method group than in the PBS group (36.36% vs 0%, P = .034). PBS technique improved the safety of laparoscopic splenectomy combined with pericardial dissection and is worthy of clinical promotion.

Improving the management of morbidly obese patients with postoperative bleeding undergoing Roux-en-Y gastric bypass.

OBJECTIVE: Aim: To improve the management of morbidly obese patients who undergo gastric bypass surgery to reduce the number of postoperative complications, in particular, bleeding. PATIENTS AND METHODS: Materials and Methods: From 2011 to 2022, a total of 348 patients with morbid obesity (MO) underwent laparoscopic gastric bypass treatment at the clinical base of the Department of General Surgery №2 of Bogomolets National Medical University. The retrospective group included 178 patients who received treatment between 2011 and 2019. 170 patients were enrolled in the prospective group for the period from 2019 to 2022. RESULTS: Results: Retrospective group had 8 episodes of postoperative bleeding, representing a rate of 4.49%, prospective group - 3 episodes of postoperative bleeding, representing a rate of 1.76% Four factor characteristics associated with the probability of bleeding were identified: "number of comorbid conditions", "arterial hypertension", "chronic liver diseases" and "chronic obstructive pulmonary disease". CONCLUSION: Conclusions: The factors responsible for the occurrence of postoperative bleeding in morbidly obese patients after laparoscopic gastric bypass surgery were the number of comorbid conditions, the presence of arterial hypertension, the presence of chronic liver diseases, and chronic obstructive pulmonary disease. A new strategy for the management of morbidly obese patients after laparoscopic gastric bypass was developed. This strategy involves changing cassettes to create gastroentero- and enteroenteroanastomoses, reducing the period of use of the nasogastric tube, drains, and urinary catheter from 3-4 days to 1 day, and resuming the drinking regimen 6 hours after extubation.

Protocol for a phase 3, randomised, active-control study of four-factor prothrombin complex concentrate versus frozen plasma in bleeding adult cardiac surgery patients requiring coagulation factor replacement: the LEX-211 (FARES-II) trial.

INTRODUCTION: Reduced thrombin generation is an important component of post cardiopulmonary bypass (CPB) coagulopathy. To replenish coagulation factors and enhance thrombin generation in bleeding surgical patients, frozen plasma (FP) and four-factor prothrombin complex concentrate (4F-PCC) are used. However, the efficacy-safety balance of 4F-PCC relative to FP in cardiac surgery is unconfirmed. METHODS AND ANALYSIS: LEX-211 (FARES-II) is an active-control, randomised, phase 3 study comparing two coagulation factor replacement therapies in bleeding adult cardiac surgical patients at 12 hospitals in Canada and the USA. The primary objective is to determine whether 4F-PCC (Octaplex/Balfaxar, Octapharma) is clinically non-inferior to FP for haemostatic effectiveness. Inclusion criteria are any index (elective or non-elective) cardiac surgery employing CPB and coagulation factor replacement with 4F-PCC or FP ordered in the operating room for bleeding management. Patients will be randomised to receive 1500 or 2000 international units of 4F-PCC or 3 or 4 units of FP, depending on body weight. The primary endpoint of haemostatic treatment response is 'effective' if no additional haemostatic intervention is required from 60 min to 24 hours after the first initiation of 4F-PCC or FP; or 'ineffective' if any other haemostatic intervention (including a second dose of study drug) is required. An estimated 410 evaluable patients will be required to demonstrate non-inferiority (one-sided α of 0.025, power ≥90%, non-inferiority margin 0.10). Secondary outcomes include transfusions, bleeding-related clinical endpoints, coagulation parameters and safety. ETHICS AND DISSEMINATION: The trial has been approved by the institutional review boards of all participating centres. Trial completion is anticipated at the end of 2024, and results will be disseminated via publications in peer-reviewed journals and conference presentations in 2025. The results will advance our understanding of coagulation management in bleeding surgical patients, potentially reducing the need for allogeneic blood products and improving outcomes in surgical patients. TRIAL REGISTRATION NUMBER: NCT05523297.

A dynamic online nomogram for predicts delayed postoperative bleeding after colorectal polyp surgery.

This study aims to analyze the risk factors associated with delayed postoperative bleeding (DPPB) following colorectal polyp surgery, develop a dynamic nomogram and evaluate the model efficacy, provide a reference for clinicians to identify the patients at high risk of DPPB. Retrospective study was done on patients who underwent endoscopic colorectal polypectomy at the First Hospital of Lanzhou University from January 2020 to March 2023. Differences between the group with and without DPPB were compared, and independent risk factors for DPPB occurrence were identified through univariate analysis and combination LASSO and logistic regression. A dynamic nomogram was constructed based on multiple logistic regression to predict DPPB following colorectal polyp surgery. Model evaluation included receiver operating characteristic (ROC), Calibration curve, Decision curve analysis (DCA). DPPB occurred in 38 of the 1544 patients included. multivariate analysis showed that direct oral anticoagulants (DOACs), polyp location in the right hemi colon, polyp diameter, drink, and prophylactic hemoclips were the independent risk factors for DPPB and dynamic nomogram were established. Model validation indicated area under the ROC curve values of 0.936, 0.796, and 0.865 for the training set, validation set, and full set, respectively. The calibration curve demonstrated a strong alignment between the predictions of the column-line diagram model and actual observations. The decision curve analysis (DCA) displayed a significant net clinical benefit across the threshold probability range of 0-100%. The dynamic nomogram aids clinicians in identifying high-risk patients, enabling personalized diagnosis and treatment.

Effect of epinephrine-mixed fascia iliaca compartment block on bleeding in total hip arthroplasty: A single-center retrospective study.

Fascia iliaca compartment block (FICB) reduces opioid consumption and pain scores after total hip arthroplasty (THA), and has recently been widely applied. We investigated whether FICB could also reduce postoperative bleeding. One hundred and fifteen consecutive patients who underwent elective THA under general anesthesia over 5 months were retrospectively analyzed. They were divided into 2 groups: the FICB group received an epinephrine-mixed FICB procedure and the control group did not receive any block. Using the hematocrit measured at 4 different time points (preoperative and 1, 24, and 48 hours after surgery), the estimated blood loss (EBL) was calculated for 3 different time periods (0-1, 1-24, 24-48 hours after surgery). EBL at 1 to 24 hours (226 vs 398 mL, P = .008) was significantly lower in the FICB group than in the control group. Additionally, the number of packed red cell (PRC) units transfused per patient over 48 hours was 0.38 units in the FICB group, which was significantly lower than the 0.70 units used in the control group (P = .040). Epinephrine-mixed FICB in THA has the potential to reduce postoperative bleeding in the first 24 hours after surgery as well as reduce PRC transfusion requirements.

In situ implantable DNA hydrogel for diagnosis and therapy of postoperative rehemorrhage following intracerebral hemorrhage surgery.

Postoperative rehemorrhage following intracerebral hemorrhage surgery is intricately associated with a high mortality rate, yet there is now no effective clinical treatment. In this study, we developed a hemoglobin (Hb)-responsive in situ implantable DNA hydrogel comprising Hb aptamers cross-linked with two complementary chains and encapsulating deferoxamine mesylate (DFO). Functionally, the hydrogel generates signals upon postoperative rehemorrhage by capturing Hb, demonstrating a distinctive "self-diagnosis" capability. In addition, the ongoing capture of Hb mediates the gradual disintegration of the hydrogel, enabling the on-demand release of DFO without compromising physiological iron-dependent functions. This process achieves self-treatment by inhibiting the ferroptosis of neurocytes. In a collagenase and autologous blood injection model-induced mimic postoperative rehemorrhage model, the hydrogel exhibited a 5.58-fold increase in iron absorption efficiency, reducing hematoma size significantly (from 8.674 to 4.768 cubic millimeters). This innovative Hb-responsive DNA hydrogel not only offers a therapeutic intervention for postoperative rehemorrhage but also provides self-diagnosis feedback, holding notable promise for enhancing clinical outcomes.

Bleeding is associated with severely impaired outcomes in surgery for acute type a aortic dissection.

Background. Surgery for acute type A aortic dissection confers a risk for significant bleeding. We analyzed the impact of massive bleeding on complications after surgery for acute type A aortic dissection. Methods. Patients undergoing surgery for acute type A aortic dissection from the retrospective multicenter Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) database 2005-2014 were eligible. Massive bleeding was defined according to the Universal Definition of Perioperative Bleeding. The primary outcome measure was early mortality and secondary outcome measures were perioperative stroke, mechanical ventilation more than 48 h, new-onset dialysis, and intensive care unit stay. Propensity score matching was performed to adjust for differences in covariates. Results. Nine hundred ninety-seven patients were included, of whom 403 (40.4%) had massive bleeding. In the propensity score-matched cohort (344 pairs), patients with massive bleeding had higher 30-day mortality (17.2 versus 7.6%, p < .001), mechanical ventilation more than 48 h (52.8 versus 22.6%, p < .001), perioperative stroke (24.3 versus 14.8%, p = .002), new-onset dialysis (22.5 versus 4.9%, p < .001), and longer intensive care unit stay (6 versus 3 days, p < .001), compared with patients without massive bleeding. Risk factors for massive bleeding were previous cardiac surgery, preoperative clopidogrel or ticagrelor therapy, DeBakey type I dissection, and localized or generalized malperfusion. Conclusions. Massive bleeding in surgery for acute type A aortic dissection is associated with a markedly increased risk for severe complications as well as early death. Further improvement of surgical technique and pharmacological optimization of coagulation is paramount to possibly improve outcomes in acute type A aortic dissection repair.

Prevention of postpancreatectomy hemorrhage after laparoscopic pancreaticoduodenectomy by wrapping ligamentum teres hepatis surrounding hepatic portal artery.

Postpancreatectomy hemorrhage (PPH) is an important risk factor for postoperative complications after laparoscopic pancreaticoduodenectomy (LPD). Recent studies have reported that the use of ligamentum teres hepatis (LTH) in LPD may reduce the risk of PPH. Therefore, this study aims to investigate whether wrapping the hepatic hilar artery with the LTH can reduce PPH after LPD. We reviewed the data of 131 patients who underwent LPD in our team from April 2018 to December 2023. The patients were divided into Groups A (60 patients) and B (71 patients) according to whether the hepatic portal artery was wrapped or not. The perioperative data of the two groups were compared to evaluate the effect of LTH wrapping the hepatic hilar artery on LPD. The platelet count of Group A was (225.25 ± 87.61) × 10^9/L, and that of Group B was (289.38 ± 127.35) × 10^9/L, with a statistically significant difference (p < 0.001). The operation time of group A [300.00 (270.00, 364.00)] minutes was shorter than that of group B [330.00 (300.00, 360.00)] minutes, p = 0.037. In addition, A set of postoperative hospital stay [12.00 (10.00, 15.00)] days shorter than group B [15.00 (12.00, 19.50)] days, p < 0.001. No PPH occurred in Group A, while 8 patients in Group B had PPH (7 cases of gastroduodenal artery hemorrhage and 1 case of proper hepatic artery hemorrhage), p = 0.019. The new technique of wrapping the hepatic hilar artery through the LTH can effectively reduce the occurrence of PPH after LPD.

The impact of early perioperative heparin-free anticoagulation for extracorporeal membrane oxygenation on bleeding and thrombotic events in lung transplantation: a retrospective cohort study.

BACKGROUND: Perioperative heparin-free anticoagulation extracorporeal membrane oxygenation (ECMO) for lung transplantation is rarely reported. OBJECTIVE: To evaluate the impact of a heparin-free strategy on bleeding and thrombotic events, blood transfusion, and coagulation function during the early perioperative period and on prognosis, and to observe its effect on different ECMO types. DESIGN: A retrospective cohort study. METHODS: Data were collected from 324 lung transplantation patients undergoing early perioperative heparin-free ECMO between August 2017 and July 2022. Clinical data including perioperative bleeding and thrombotic events, blood product transfusion, coagulation indicators and 1-year survival were analysed. RESULTS: Patients were divided in venovenous (VV; n = 251), venoarterial (VA; n = 40) and venovenous-arterial (VV-A; n = 33) groups. The VV group had the lowest intraoperative bleeding and thoracic drainage within 24 h postoperatively. Vein thrombosis occurred in 30.2% of patients within 10 days postoperatively or 1 week after ECMO withdrawal, and no significant difference was found among the three groups. Double lung transplantation, increased intraoperative bleeding, and increased postoperative drainage were associated with vein thrombosis. Except for acute myocardial infarction in one patient, no other serious thrombotic events occurred. The VV-ECMO group had the lowest demand for blood transfusion. The highest prothrombin time and the lowest fibrinogen levels were observed in the VA group during ECMO run, while the highest platelet counts were found in the VV group. Both intraoperative bleeding and thoracic drainage within 24 h postoperatively were independent predictors for 1-year survival, and no thrombosis-related deaths occurred. CONCLUSION: Short-term heparin-free anticoagulation, particularly VV-ECMO, did not result in serious thrombotic events or thrombosis-related deaths, indicating that it is a safe and feasible strategy for perioperative ECMO in lung transplantation.

A case report of a bleeding case after removal of chest drain after lung surgery.

RATIONALE: Postoperative bleeding after lobectomy is relatively rare. By analyzing and discussing the case history and management of hemorrhagic shock caused by chest tube removal after lobectomy, we can achieve the purpose of preventing postoperative bleeding after thoracic surgery and reducing postoperative complications, which can help avoid the risk of second surgery, shorten the patient's hospital stay, reduce the cost of medical care, and improve the patient's quality of life. PATIENT CONCERNS: A case of bleeding from tube removal after lobectomy. The bleeding from chest drain removal on the 3rd day after thoracoscopic lobectomy resulted in hemorrhagic shock, which was stopped by thoracoscopic exploration again under active antishock, and there was no recurrence of bleeding after the operation, and the patient was discharged from the hospital after chest drain removal. DIAGNOSES: Enhanced computed tomography of the chest revealed a space-occupying lesion in the middle lobe of the right lung. INTERVENTIONS: Thoracoscopy was performed again on the condition of active anti-shock. OUTCOMES: On the third day after thoracoscopic lobectomy, the patient underwent removal of the chest drain and subsequently experienced hemorrhagic shock. Given the necessity of maintaining anti-shock measures, the patient was subjected to a second thoracoscopic exploration with the objective of halting the hemorrhage. Following this procedure, the patient did not present with any further episodes of bleeding. Subsequently, a new chest drain was placed, and once the drainage flow had diminished to an acceptable level, the chest drain was removed. The patient subsequently made a full recovery and was discharged from the hospital. LESSONS: Even if the safely inserted drain tube is removed, the thoracic surgeon must be aware of possible vascular bleeding.

Peri-operative Anticoagulation Strategies, Bleeding and Thrombotic Complications in Pediatric Patients Undergoing Intervention for Congenital Portosystemic Shunts.

BACKGROUND: Congenital portosystemic shunts (CPSS) are rare congenital abnormalities causing abnormal blood flow between the portal vein and systemic circulation. This study reports on the peri-operative anticoagulation management of CPSS patients post closure, focusing on the incidence of thrombotic and bleeding complications. METHODS: This is a single-center retrospective analysis of CPSS patients who underwent surgery or endovascular intervention between 2005 and 2021. The protocol included unfractionated heparin (UFH) during and immediately after surgery, followed by either warfarin or low molecular weight heparin (LMWH) postoperatively. Outcomes assessed included postoperative thrombotic and bleeding complications. RESULTS: A total of 44 patients were included. Postoperatively, 89% received treatment-dose UFH, transitioning to warfarin or LMWH at discharge. Thrombotic complications occurred in 16% of patients, predominantly in the superior mesenteric vein. Surgical interventions and continuous infusion of tissue plasminogen activator (tPA) were used for clot resolution. Bleeding complications were observed in 64% of patients, primarily managed with transfusions and temporary UFH interruption. No deaths related to thrombotic, or bleeding events were reported. CONCLUSIONS: Our findings underscore the delicate balance required in anticoagulation management for CPSS patients, revealing an occurrence of both thrombotic and bleeding complications postoperatively. LEVELS OF EVIDENCE: Level II, retrospective study.

Intraarticular TXA Administration with Appropriate Timing of Clamping and Appropriate Dose is More Effective Than IV Administration.

PURPOSE OF THE STUDY: Our aim was to compare the effects of intraarticular and intravenous (IV) tranexemic acid (TXA) application on bleeding and complication rates in patients who underwent total knee arthroplasty (TKA). MATERIAL AND METHODS: Between 2017 and 2021, 406 patients who underwent TKA with 2 g of IV TXA and retrograde 1.5 g of TXA applied through the drain were included in the study. Of the patients, 206 were in the IV TXA group. Preoperative and postoperative hemoglobin levels, drain output, BMI, ASA score, blood loss, and the number of transfused patients were recorded. Complications such as symptomatic venous thromboembolism were also recorded. RESULTS: There was no significant difference between the two groups in terms of age, sex, American Society of Anesthesiologists (ASA) score, or BMI (p = 0.68, 0.54, 0.28, 0.45). Total drain output and blood loss were significantly higher in the IV TXA group than in the intraarticular TXA group (p < 0.0001, p < 0.0001). Eighteen patients in the IV TXA group and 1 patient in the intraarticular TXA group received a blood transfusion (p < 0.0001). There was no difference between the two groups in terms of preoperative hemoglobin or platelet count (p = 0.24). However, postoperative hemoglobin level was higher in the patients who received intraarticular TXA (p=0.0005). More thromboembolism events were seen in the IV TXA group (p < 0.0001). CONCLUSIONS: Intraarticular TXA application reduces blood loss more than IV application, reduces the blood transfusion rate, and causes fewer complications. KEY WORDS: tranexemic acid, total knee arthroplasty, intraarticular injection, blood loss, blood transfusion.

Urinary N-acetyl-D-glucosaminidase can predict bleeding after a percutaneous kidney biopsy.

BACKGROUND: A percutaneous kidney biopsy (PKB) allows nephrologists to make informed decisions for treating various kidney diseases; however, the risk of bleeding complications should be considered, given the vascularity of the kidney. Many studies have reported risk factors for bleeding events after a PKB. However, while urinary N-acetyl-ß-D-glucosaminidase (NAG) is a useful biomarker of kidney disease severity, little is known about whether or not urinary NAG is related to the bleeding risk. METHODS: Medical records of patients who underwent a PKB at the National Defense Medical College Hospital between October 2018 and October 2023 were retrospectively studied. Hemoglobin (Hb) loss ≥ 1 g/dL was defined as a bleeding event. RESULTS: Of the 213 patients, 110 (51.6%) were men, and the median age was 56 years old (interquartile range 40-71). The most frequent diagnosis on a PKB was IgA nephropathy (N = 72; 34.0%). Fifty-four patients (25.3%) experienced Hb loss ≥ 1 g/dL after a PKB, and urinary NAG/Cr levels before the biopsy were able to predict a bleeding event, with an area under the receiver operating characteristic curve of 0.65 (p = 0.005). Using the optimal cutoff value of 35 U/gCr, urinary NAG/Cr was found to be an independent risk factor by multiple logistic regression analysis (odds ratio 3.21, 95% confidence interval 1.42-7.27, p = 0.005). Even after adjusting for previously-reported risk factors, the elevated urinary NAG/Cr ratio remained a statistically significant variable. Compared with the pathological findings, only the severity of multilayered elastic laminae of the small muscular artery was associated with both urinary NAG/Cr levels (p = 0.008) and bleeding events (p = 0.03). CONCLUSION: Urinary NAG successfully predicted not only the severity of kidney disorders but also bleeding events after a PKB. Arteriosclerosis in the kidneys may be the mechanism underlying these increased bleeding events.