Postoperative abdominal bleeding

Preoperative consultation for determining the appropriate transfusion strategy

Surgical patients are at risk of postoperative complications and mortality, necessitating preoperative patient optimization through the identification and correction of modifiable risk factors. Although preoperative platelet transfusions aim to reduce the risk of bleeding, their efficacy remains uncertain. Similarly, red blood cell transfusion in patients with anemia does not reduce the risk of postoperative mortality and may exacerbate complications. Therefore, developing individualized strategies that focus on correcting preoperative complete blood count abnormalities and minimizing transfusion requirements are essential. This review aimed to examine complete blood count abnormalities and appropriate transfusion strategies to minimize postoperative complications.

Usefulness of the hybrid technique of interventional radiology and endoscopic treatment for intestinal bleeding after pancreaticoduodenectomy: a case report

Introduction and importance

In endovascular treatment of ruptured pseudoaneurysm after pancreaticoduodenectomy (PD) with gastrointestinal bleeding, treatment for vasospasm of the culprit vessel from haemorrhagic shock and subsequent reperfusion has not been determined before.

Case presentation

The authors hereby present you with a case of a 59-year-old man with unknown operative method upon arrival at the Emergecy room and who had hematemesis and collapse 6 months post-PD surgery.

Clinical discussion

An initial contrast-enhanced computed tomography (CT) revealed no obvious source of bleeding, so an upper gastrointestinal endoscope was performed. Rebleeding occurred during the examination, and interventional radiology was performed because haemostasis was difficult. Coil embolization was performed for leakage of contrast material from the gastroduodenal artery stump into the gastrointestinal tract. However, because the embolization was uncertain due to vasospasm of the common hepatic artery, endoscopic clipping of the perforation site was also performed to prevent rebleeding due to reperfusion after improvement of vasospasm. A CT scan 5 days later showed reperfusion of the coil-implanted vessel. No rebleeding or hepatic infarction occurred postoperatively.

Conclusion

In this case, the haemostasis by coil embolization was uncertain due to the presence of vasospasm, and clipping was used in combination with the procedure to prevent rebleeding.

An All-In-One Transient Theranostic Platform for Intelligent Management of Hemorrhage

Developing theranostic devices to detect bleeding and effectively control hemorrhage in the prehospital setting is an unmet medical need. Herein, an all-in-one theranostic platform is presented, which is constructed by sandwiching silk fibroin (SF) between two silver nanowire (AgNW) based conductive electrodes to non-enzymatically diagnose local bleeding and stop the hemorrhage at the wound site. Taking advantage of the hemostatic property of natural SF, the device is composed of a shape-memory SF sponge, facilitating blood clotting, with ≈82% reduction in hemostatic time in vitro as compared with untreated blood. Furthermore, this sandwiched platform serves as a capacitive sensor that can detect bleeding and differentiate between blood and other body fluids (i.e., serum and water) via capacitance change. In addition, the AgNW electrode endows anti-infection efficiency against Escherichia coli and Staphylococcus aureus. Also, the device shows excellent biocompatibility and gradually biodegrades in vivo with no major local or systemic inflammatory responses. More importantly, the theranostic platform presents considerable hemostatic efficacy comparable with a commercial hemostat, Dengen, in rat liver bleeding models. The theranostic platform provides an unexplored strategy for the intelligent management of hemorrhage, with the potential to significantly improve patients' well-being through the integration of diagnostic and therapeutic capabilities.

Analysis of the risk factors for secondary hemorrhage after abdominal surgery

Introduction

This study aimed to conduct a clinical review and analysis to recommend options for the prevention and treatment of postoperative hemorrhage.

Patients and Methods

A total of 138 patients who experienced postoperative hemorrhage after abdominal surgery in the period between January 2015 and December 2020 at the Sir Run Run Shaw Hospital, affiliated to Zhejiang University School of Medicine, participated in this study. They were divided into a group with primary bleeding only and a secondary bleeding group. Univariate and multivariate statistical analyses were performed, followed by plotting of cumulative hazard and survival curves for the two groups.

Results

The main factors of interest found to be associated with secondary hemorrhage were duration of the operation, the time of the first bleeding incident, intervention time, performance of combined organ resection, use of surgical intervention, occurrence of abdominal infection, admission to the intensive care unit (ICU), postoperative length of stay, and total hospitalization expenses. Among these, a long operative duration (>5 h) and an extended intervention time (>5 h) were identified as independent predictors of risk of secondary hemorrhage.

Conclusions

Secondary hemorrhage after abdominal surgery is mainly associated with subjective human factors, and it is an important cause of poor prognosis and even death. Proper reductions in operation time and implementation of a quick response to bleeding are the key factors in tackling bleeding. Further reduction in the rates of postoperative hemorrhage and mortality will require a concerted effort by surgeons in terms of both intraoperative surgical techniques and postoperative management.

Study of ultrasound-guided percutaneous microwave ablation combined with portal vein embolization for rapid future liver remnant increase of planned hepatectomy

Purpose

To evaluate the efficacy of ultrasound-guided percutaneous microwave ablation (PMA) combined with portal vein embolization (PVE) for planned hepatectomy.

Methods

We retrospectively reviewed data of 18 patients with multiple right liver tumors or hilar tumor of liver invades the surrounding tissue and insufficient future liver remnant (FLR) for hepatectomy from July 2015 to March 2017. Ultrasound-guided PMA was performed by using PMCT cold circulation microwave treatment apparatus. PVE was performed after PMA. The increase of FLR was evaluated by computed tomography (CT) 6-22 days after PVE. The proportion of FLR, increase in the amplitude of FLR, procedure-related complications, perioperative morbidity and mortality, and overall survival (OS) rates, the median survival time were analyzed.

Results

The median volume of FLR before PMA and PVE was 369.7 ml (range: 239.4-493.1 ml). After a median waiting period of 11.5 days (range: 6-22 days), the median volume of FLR was increased to 523.4 ml (range: 355.4-833.3 ml). The changes in FLR before and after PMA and PVE were statistically significant (p<0.001). No serious perioperative complications or mortality were found. After a median follow-up time of 51.0 months (range: 2-54 months), the 6-month, 1-year, 2-year, 3-year and 4-year survival rates were 88.9%, 72.2%, 44.4%, 33.3%, 22.2%, respectively, and the median survival time was 15.0 ± 7.1 months.

Conclusion

PMA combined with PVE increases FLR rapidly, avoids touching malignant tumors, and produces fewer procedure-related complications. It appears safe and efficacious for planned hepatectomy.

ENDOVASCULAR DIAGNOSTICS AND TREATMENT OF HEMORRHAGES IN MILITARY AND CIVILIAN PATIENTS FOLLOWING ABDOMINAL SURGERY

OBJECTIVE

The aim: The retrospective analysis of the angiographic picture and clinical results of endovascular treatment of patients with postoperative abdominal and gastrointestinal bleeding was carried out.

PATIENTS AND METHODS

Materials and methods: The results of 447 endovascular diagnostic and therapeutic interventions in 391 patients (46 military and 345 civilians) with postoperative bleeding performed from 2012 to 2022 were studied. According to computer tomography with contrast enhancement, the source of bleeding was identified in 216 (67.7%) cases.

RESULTS

Results: In 345 (88.2%) patients, it was possible to reliably identify the source of bleeding on angiography. In 46 (11.8%) patients with an unexplained source of bleeding, the target arterial pool was determined on the basis of localization, volume, and features of surgical intervention and considered as preventive interventions. A total of 447 endovascular hemostatic interventions were performed on 391 patients. A stent graft was installed in 27 patients, 420 embolization were performed in 364 patients. Thus, in 43 (11.0%) patients, embolization was performed repeatedly, in 12 cases - three times, in 1 case - four times. In 16 cases (15 cases of prophylactic embolization), endovascular hemostasis was ineffective and required subsequent surgical intervention.

CONCLUSION

Conclusions: Endovascular interventions are an effective method of diagnosis and treatment of postoperative abdominal bleeding. Prophylactic embolization allows you to prevent the recurrence of postoperative bleeding with an instrumentally undiagnosed source, however, you need to be prepared for the multi-stage treatment aimed at sequentially shutting down the collateral blood supply to the damaged area.

Modulating Nanoparticle Size to Understand Factors Affecting Hemostatic Efficacy and Maximize Survival in a Lethal Inferior Vena Cava Injury Model

Intravenous nanoparticle hemostats offer a potentially attractive approach to promote hemostasis, in particular for inaccessible wounds such as noncompressible torso hemorrhage (NCTH). In this work, particle size was tuned over a range of <100-500 nm, and its effect on nanoparticle-platelet interactions was systematically assessed using in vitro and in vivo experiments. Smaller particles bound a larger percentage of platelets per mass of particle delivered, while larger particles resulted in higher particle accumulation on a surface of platelets and collagen. Intermediate particles led to the greatest platelet content in platelet-nanoparticle aggregates, indicating that they may be able to recruit more platelets to the wound. In biodistribution studies, smaller and intermediate nanoparticles exhibited longer circulation lifetimes, while larger nanoparticles resulted in higher pulmonary accumulation. The particles were then challenged in a 2 h lethal inferior vena cava (IVC) puncture model, where intermediate nanoparticles significantly increased both survival and injury-specific targeting relative to saline and unfunctionalized particle controls. An increase in survival in the second hour was likewise observed in the smaller nanoparticles relative to saline controls, though no significant increase in survival was observed in the larger nanoparticle size. In conjunction with prior in vitro and in vivo experiments, these results suggest that platelet content in aggregates and extended nanoparticle circulation lifetimes are instrumental to enhancing hemostasis. Ultimately, this study elucidates the role of particle size in platelet-particle interactions, which can be a useful tool for engineering the performance of particulate hemostats and improving the design of these materials.

CT of acute abdominopelvic hemorrhage: protocols, pearls, and pitfalls

Abdominal and pelvic hemorrhage may be secondary to a number of causes and is often a medical emergency. Patient presentation ranges from obvious trauma with evidence of hemodynamic instability to vague symptoms. CT has become the imaging modality of choice for identifying abdominopelvic hemorrhage. Recognizing acute hemorrhage as well as identifying its location and severity are key to expediting management. In the Emergency Department, ultrasound often used in the initial evaluation of trauma patients, but is not sensitive for subtle bleeds or injuries. CT is the best first-line imaging tool to identify abdominal hemorrhage and, compared with angiography, has been shown to be superior in detecting intra-abdominal bleeding, especially when the bleeding rate is low. Depending on location and etiology, abdominopelvic hemorrhage may have a characteristic appearance, such as the "sentinel clot" sign associated with blunt trauma to the solid organs or the "triangle sign" of a mesenteric bleed. The following pictorial essay reviews CT technique, study interpretation, and interpretative pearls and pitfalls in the recognition of acute abdominopelvic hemorrhage.

Fatal arterial hemorrhage after pancreaticoduodenectomy: How do we simultaneously accomplish complete hemostasis and hepatic arterial flow?

BACKGROUND

Although arterial hemorrhage after pancreaticoduodenectomy (PD) is not frequent, it is fatal. Arterial hemorrhage is caused by pseudoaneurysm rupture, and the gastroduodenal artery stump and hepatic artery (HA) are frequent culprit vessels. Diagnostic procedures and imaging modalities are associated with certain difficulties. Simultaneous accomplishment of complete hemostasis and HA flow preservation is difficult after PD. Although complete hemostasis may be obtained by endovascular treatment (EVT) or surgery, liver infarction caused by hepatic ischemia and/or liver abscesses caused by biliary ischemia may occur. We herein discuss therapeutic options for fatal arterial hemorrhage after PD.

AIM

To present our data here along with a discussion of therapeutic strategies for fatal arterial hemorrhage after PD.

METHODS

We retrospectively investigated 16 patients who developed arterial hemorrhage after PD. The patients’ clinical characteristics, diagnostic procedures, actual treatments [transcatheter arterial embolization (TAE), stent-graft placement, or surgery], clinical courses, and outcomes were evaluated.

RESULTS

The frequency of arterial hemorrhage after PD was 5.5%. Pancreatic leakage was observed in 12 patients. The onset of hemorrhage occurred at a median of 18 d after PD. Sentinel bleeding was observed in five patients. The initial EVT procedures were stent-graft placement in seven patients, TAE in six patients, and combined therapy in two patients. The rate of technical success of the initial EVT was 75.0%, and additional EVTs were performed in four patients. Surgical approaches including arterioportal shunting were performed in eight patients. Liver infarction was observed in two patients after TAE. Two patients showed a poor outcome even after successful EVT. These four patients with poor clinical courses and outcomes had a poor clinical condition before EVT. Fourteen patients were successfully treated.

CONCLUSION

Transcatheter placement of a covered stent may be useful for simultaneous accomplishment of complete hemostasis and HA flow preservation.

Platelet safety range before splenectomy for hypersplenism: based on 244 cases of splenectomy in hepatolenticular degeneration patients

Background and study aims

To investigate the safety and efficacy of splenectomy for hepatolenticular degeneration (HLD) patients with PLT less than 20 × 10⁹/L.

Patients and methods

A total of 244 HLD patients with hypersplenism underwent splenectomy. According to the preoperative PLT values, the patients were divided into three groups : group A of 53 patients with PLT < 20 × 10⁹/L ; group B of 92 patients with 20 × 10⁹/L ≤ PLT ≤ 30 × 10⁹/L ; group C of 99 patients with PLT > 30 × 10⁹/L. General information including : blood cell counts, liver function , coagulation function 1 day before sugery and 1, 7, 14 days after surgery ; intraoperative blood loss ; operation time ; vital signs at the beginning, at 60 minutes and the end of the operation. Pressure and blood oxygen ; postoperative drainage ; postoperative complications and mortality.

Results

Blood cell counts, liver function, and coagulation function were improved after splenectomy in three groups (P<0.05) ; there was no significant difference in blood loss, operation time, vital signs during the operation, postoperative drainage, postoperative complications and mortality between three groups (P>0.05).

Conclusion

For HLD patients with hypersplenism, it is safe and effective to conduct splenectomy under PLT < 20 × 10⁹/L.

Methane Exhalation Can Monitor the Microcirculatory Changes of the Intestinal Mucosa in a Large Animal Model of Hemorrhage and Fluid Resuscitation

Background: Internal hemorrhage is a medical emergency, which requires immediate causal therapy, but the recognition may be difficult. The reactive changes of the mesenteric circulation may be part of the earliest hemodynamic responses to bleeding. Methane is present in the luminal atmosphere; thus, we hypothesized that it can track the intestinal circulatory changes, induced by hemorrhage, non-invasively. Our goal was to validate and compare the sensitivity of this method with an established technique using sublingual microcirculatory monitoring in a large animal model of controlled, graded hemorrhage and the early phase of following fluid resuscitation.

Materials and Methods: The experiments were performed on anesthetized, ventilated Vietnamese minipigs (approval number: V/148/2013; n = 6). The animals were gradually bled seven times consecutively of 5% of their estimated blood volume (BV) each, followed by gradual fluid resuscitation with colloid (hydroxyethyl starch; 5% of the estimated BV/dose) until 80 mmHg mean arterial pressure was achieved. After each step, macrohemodynamic parameters were recorded, and exhaled methane level was monitored continuously with a custom-built photoacoustic laser-spectroscopy unit. The microcirculation of the sublingual area, ileal serosa, and mucosa was examined by intravital videomicroscopy (Cytocam-IDF, Braedius).

Results: Mesenteric perfusion was significantly reduced by a 5% blood loss, whereas microperfusion in the oral cavity deteriorated after a 25% loss. A statistically significant correlation was found between exhaled methane levels, superior mesenteric artery flow (r = 0.93), or microcirculatory changes in the ileal serosa (ρ = 0.78) and mucosa (r = 0.77). After resuscitation, the ileal mucosal microcirculation increased rapidly [De Backer score (DBS): 2.36 ± 0.42 vs. 8.6 ± 2.1 mm⁻¹], whereas serosal perfusion changed gradually and with a lower amplitude (DBS: 2.51 ± 0.48 vs. 5.73 ± 0.75). Sublingual perfusion correlated with mucosal (r = 0.74) and serosal (r = 0.66) mesenteric microperfusion during the hemorrhage phase but not during the resuscitation phase.

Conclusion: Detection of exhaled methane levels is of diagnostic significance during experimental hemorrhage as it indicates blood loss earlier than sublingual microcirculatory changes and in the early phase of fluid resuscitation, the exhaled methane values change in association with the mesenteric perfusion and the microcirculation of the ileum.

What is the Role of Image-Guided Endovascular Surgery in Postbariatric Surgery Bleeding Complications?

Background: Obesity treatment requires surgical procedures included in bariatric surgery. Bleeding complications are reported in 1%-4%. Image-guided surgery (IGS) includes minimally invasive procedures that have the advantage of less aggression to the patient, fewer complications, and a quick recovery. Endovascular therapy by interventional radiology (IR) is a minimally invasive image-guided procedure widely used in central, peripheral, and splanchnic vascular pathology. Treatment of postoperative bleeding in bariatric surgery can be aided by image-guided endovascular procedures. Objectives: The aim of this study is to carry out an update on the application of IR in bariatric surgery bleeding complications. Bleeding Complications: General rate of postoperative complications in bariatric surgery is 0%-10%. Postoperative bleeding (1%-4%) can be gastrointestinal (endoscopic treatment) or intra-abdominal (surgical treatment/relaparoscopy). In the case of arterial vascular lesions that cannot be resolved either endoscopically or surgically, the option of endovascular treatment with IR should be considered. Conclusions: Endovascular approach through IR and IGS in bleeding complications after bariatric surgery is presented as a valid minimally invasive therapy option in this group of patients.

Saline versus Lactated Ringer’s Solution

Background

Both saline and lactated Ringer’s solutions are commonly given to surgical patients. However, hyperchloremic acidosis consequent to saline administration may provoke complications. The authors therefore tested the primary hypothesis that a composite of in-hospital mortality and major postoperative complications is less common in patients given lactated Ringer’s solution than normal saline.

Methods

The authors conducted an alternating cohort controlled trial in which adults having colorectal and orthopedic surgery were given either lactated Ringer’s solution or normal saline in 2-week blocks between September 2015 and August 2018. The primary outcome was a composite of in-hospital mortality and major postoperative renal, respiratory, infectious, and hemorrhagic complications. The secondary outcome was postoperative acute kidney injury.

Results

Among 8,616 qualifying patients, 4,187 (49%) were assigned to lactated Ringer’s solution, and 4,429 (51%) were assigned to saline. Each group received a median 1.9 l of fluid. The primary composite of major complications was observed in 5.8% of lactated Ringer’s versus 6.1% of normal saline patients, with estimated average relative risk across the components of the composite of 1.16 (95% CI, 0.89 to 1.52; P = 0.261). The secondary outcome, postoperative acute kidney injury, Acute Kidney Injury Network stage I–III versus 0, occurred in 6.6% of lactated Ringer’s patients versus 6.2% of normal saline patients, with an estimated relative risk of 1.18 (99.3% CI, 0.99 to 1.41; P = 0.009, significance criterion of 0.007). Absolute differences between the treatment groups for each outcome were less than 0.5%, an amount that is not clinically meaningful.

Conclusions

In elective orthopedic and colorectal surgery patients, there was no clinically meaningful difference in postoperative complications with lactated Ringer’s or saline volume replacement. Clinicians can reasonably use either solution intraoperatively.

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Effect of Qihuang Decoction Combined with Enteral Nutrition on Postoperative Gastric Cancer of Nutrition and Immune Function

Objective

Early nutritional support in patients with gastric cancer can improve their nutritional status, but the impact on immune function has not been confirmed. This study aimed to analyze the effects of Qihuang decoction combined with enteral nutrition on nutrition and the immune function of postoperative gastric cancer.

Methods

120 patients with postoperative gastric cancer in the study group and 117 in the control group were selected as the study subjects from our hospital at random. Indications of nutrition and immune and the rates of complications were compared the day before surgery and 1, 3, 7, and 14 days after surgery.

Results

Indications of nutrition except hemoglobin (HB) in the study group were significantly higher than those before operation and the albumin (ALB) and prealbumin (TP) were significantly increased 7 and 14 days after surgery (P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 and P < 0.001 versus P < 0.001 and P < 0.001) and the protein (PA) 3, 7, and 14 days after surgery (P=0.011, P=0.002, and P=0.022) in the study group compared to those in the control group. Cellular and humoral immunity indications in the study group are significantly higher than those before operation compared to those in the control group, and the CD3⁺, CD4⁺, and CD4⁺/CD8⁺ were significantly increased 7 and 14 days after surgery (P=0.027 and P < 0.001 versus P=0.008 and P < 0.001 versus P=0.010 and P < 0.001) and IgA, IgG, and IgM 3, 7, and 14 days after surgery in the study group (P < 0.001, P < 0.001, and P < 0.001 versus P < 0.001, P < 0.002, and P < 0.001 versus P < 0.001, P < 0.001, and P < 0.001). The complications such as abdominal, lung, wound, and urinary infection were also significantly decreased (P^χ2=0.017; P < 0.001 and P < 0.001 versus P < 0.001 and P < 0.001) and the protein (PA) 3, 7, and 14 days after surgery (P=0.011, P=0.002, and P=0.022) in the study group compared to those in the control group. Cellular and humoral immunity indications in the study group are significantly higher than those before operation compared to those in the control group, and the CD3⁺, CD4⁺, and CD4⁺/CD8⁺ were significantly increased 7 and 14 days after surgery (P=0.027 and P < 0.001 versus P=0.008 and P < 0.001 versus P=0.010 and P < 0.001) and IgA, IgG, and IgM 3, 7, and 14 days after surgery in the study group (P < 0.001, P < 0.001, and P < 0.001 versus P < 0.001, P < 0.002, and P < 0.001 versus P < 0.001, P < 0.001, and P < 0.001). The complications such as abdominal, lung, wound, and urinary infection were also significantly decreased (P^χ2=0.017; P < 0.001 and P < 0.001 versus P < 0.001 and P < 0.001) and the protein (PA) 3, 7, and 14 days after surgery (P=0.011, P=0.002, and P=0.022) in the study group compared to those in the control group. Cellular and humoral immunity indications in the study group are significantly higher than those before operation compared to those in the control group, and the CD3⁺, CD4⁺, and CD4⁺/CD8⁺ were significantly increased 7 and 14 days after surgery (P=0.027 and P < 0.001 versus P=0.008 and P < 0.001 versus P=0.010 and P < 0.001) and IgA, IgG, and IgM 3, 7, and 14 days after surgery in the study group (P < 0.001, P < 0.001, and P < 0.001 versus P < 0.001, P < 0.002, and P < 0.001 versus P < 0.001, P < 0.001, and P < 0.001). The complications such as abdominal, lung, wound, and urinary infection were also significantly decreased (P^χ2=0.017; P < 0.001 and P < 0.001 versus P < 0.001 and P < 0.001) and the protein (PA) 3, 7, and 14 days after surgery (P=0.011, P=0.002, and P=0.022) in the study group compared to those in the control group. Cellular and humoral immunity indications in the study group are significantly higher than those before operation compared to those in the control group, and the CD3⁺, CD4⁺, and CD4⁺/CD8⁺ were significantly increased 7 and 14 days after surgery (P=0.027 and P < 0.001 versus P=0.008 and P < 0.001 versus P=0.010 and P < 0.001) and IgA, IgG, and IgM 3, 7, and 14 days after surgery in the study group (P < 0.001, P < 0.001, and P < 0.001 versus P < 0.001, P < 0.002, and P < 0.001 versus P < 0.001, P < 0.001, and P < 0.001). The complications such as abdominal, lung, wound, and urinary infection were also significantly decreased (P^χ2=0.017; P^χ2=0.036; P^χ2=0.041; P^χ2=0.004).

Conclusions

Qihuang decoction combined with enteral nutrition can promote the absorption of enteral nutrition with improving the immune and reducing complications of infection.

Identifying emergency pathology on abdominopelvic CT for non-radiologists

Abdominal and pelvic computed tomography (CT) scans can be complex to interpret but sometimes significant abnormalities are relatively easy to recognize. In emergencies it is beneficial if physicians and surgeons can identify significant pathology that may immediately change patient management. Early image interpretation will allow clinicians to alert radiologists to provide prompt urgent reports, facilitate early referral to other specialities or expedite emergency surgery. This article provides non-radiologists with a systematic approach to identifying emergency pathology on abdominal and pelvic CT scans. It reviews the relevant cross-sectional anatomy and discusses the CT appearances of bowel perforation, bowel obstruction, bowel ischaemia (gangrene), bleeding, appendicitis and hydronephrosis using illustrative examples from the authors' clinical practice. Underlying causes for these conditions and the importance of interpreting the radiological appearances in conjunction with the patient's clinical condition and history are discussed. The authors hope that by using the POGBAH acronym and a systematic approach readers will be able to identify emergency pathology on abdominal and pelvic CT which may improve patient care.

Urgent Multidetector Computed Tomography in Colon Cancer: Postsurgical Changes and Early Complications

Complications after surgery for colorectal cancer are common in emergency departments. Multidetector computed tomography plays a fundamental role in the follow-up of patients after surgery, because it enables the detection of relapse and complications. Radiologists need to be familiar with different surgical techniques and the normal postsurgical changes so that we can differentiate them from potential complications and relapse. This article reviews the multidetector computed tomography findings that can be considered normal after surgical intervention for colorectal cancer as well as the most common early complications seen in postsurgical colorectal cancer patients presenting at emergency departments.

Postoperative bleeding risk prediction for patients undergoing colorectal surgery

BACKGROUND

There is limited consensus regarding risk factors for postoperative bleeding. The objective of this work was to investigate the capability of machine learning techniques in combination with practice-based longitudinal electronic medical record data for identifying potential new risk factors for postoperative bleeding and predicting patients at high risk of postoperative bleeding.

METHODS

A retrospective study was conducted for patients who underwent colorectal surgery 1998-2015 at a single tertiary referral center. Various predictors were extracted from electronic medical record. The outcome of interest was the occurrence of postoperative bleeding within 7 days of surgery. Logistic regression and gradient boosting machine models were trained. Area under the receiver operating curve and area under the precision recall curve were used to evaluate the performance to different models.

RESULTS

Of 13,399 cases undergoing colorectal resection, 1,680 (12.5%) experienced postoperative bleeding. A total of 299 variables were evaluated. Logistic regression and gradient boosting machine models returned an area under the receiver operating curve of 0.735 and 0.822 and area under the precision recall curve of 0.287 and 0.423, respectively. In addition to well-known risk factors for postoperative bleeding, nutrition (ranked third), weakness (ranked fifth), patient mobility (ranked sixth), and activity level (ranked eighth) were found to be novel predictors in the gradient boosting machine model based on permutation importance.

CONCLUSION

The study identified measures of functional capacity of patient as novel predictors of postoperative bleeding. The study found that risk of postoperative bleeding can be assessed, allowing for better use of human resources in addressing this important adverse event after surgery.

Transcatheter Arterial Embolization for Postoperative Bleeding Following Abdominal Surgery

PURPOSE

We aimed to estimate the usefulness of transcatheter arterial embolization (TAE) in patients with postoperative abdominal hemorrhage and to evaluate the effects of pancreatic fistula on clinical outcomes and angiographic findings.

MATERIALS AND METHODS

We enrolled 22 patients (20 males and 2 females; mean age 63 years; range 25-86 years), who underwent transarterial angiography for postoperative hemorrhage after abdominal surgery. This group corresponded to 28 procedures. Technical and clinical success rates were calculated, and clinical findings and outcomes were compared between patients with and without a pancreatic fistula.

RESULTS

Pre-interventional CT was performed in all patients before first angiography, and the location of the bleeding was identified in all but one patient. Active arterial bleeding, identified by extravasation of contrast agent (n = 12), pseudoaneurysm formation (n = 12), and arterial wall irregularity (n = 2) were detected in 28 angiographic procedures, and embolization was performed in 26 instances. Various embolization techniques such as isolation, packing, embolization, and stentgraft implantation were performed. The technical and clinical success rates were 96% (25/26 procedures) and 82% (18/22 patients), respectively. In hemodynamically unstable patients (shock index: heart rate/systolic blood pressure > 1), a 92% (12/13 cases) technical success rate was achieved. There were no significant differences in any evaluated parameters between patients with and without pancreatic fistula.

CONCLUSION

TAE is a safe and effective for treating postoperative hemorrhage even in patients with hemodynamic instability and pancreatic fistula. Additionally, pre-interventional CT is useful for effective, consecutive interventions.