Abdominal Complications After Heart Surgery

Characteristics, incidence, and outcomes of gastrointestinal complications post cardiac surgery in a quaternary referral centre: A retrospective study

BACKGROUND

Gastrointestinal (GI) complications after cardiac surgery are associated with high morbidity and mortality. Early identification and treatment of GI complications could improve patient outcomes.

OBJECTIVES

The objective of this study was to ascertain the incidence, risk factors, and clinical outcomes of GI complications following cardiac surgery.

METHODS

A retrospective single-centre cohort study of adult patients undergoing cardiac surgery in an Australian quaternary cardiothoracic surgical referral centre was conducted from November 2012 to March 2020. Preoperative, intraoperative, and postoperative characteristics were compared between patients who did and did not develop GI complications. Data are presented as n (%). Between-group comparisons were analysed using Chi-square and Fisher's exact tests (where n < 6) for categorical variables and Wilcoxon rank-sum test for continuous variables.

RESULTS

Of the 4417 patients who underwent cardiac surgery, 95 (2.2%) patients developed a total of 100 GI complications, with the most common being paralytic ileus (n = 22/100, 22%). Baseline characteristics and preoperative factors associated with GI complications included an age of >70 years (GI complication vs no GI complication: 55.8% vs 37.6%; p = 0.000), preexisting diabetes (49.5% vs 34.5%; p = 0.002), and a creatinine level >200 mcg/ml (11.6% vs 3.7%; p = 0.000). Intra-operative factors included a cardiopulmonary bypass time >120 min (28.4% vs 15.5%; p < 0.01). Postoperatively, developing a GI complication was associated with return to theatre (36.8% vs 13.9%; p < 0.01) and new stroke, pneumonia, and acute kidney injury (all p < 0.01). Patients with a GI complication had a higher intensive care unit and hospital mortality (7.4% vs 1.1%, and 13.6% vs 1.4%, respectively), and a longer intensive care unit and hospital stay (5.5 vs 2.3 days, and 24.0 vs 10.3 days).

CONCLUSIONS

Multiple risk factors associated with GI complications in cardiac surgery patients were identified. These provide potential targets to support the early detection and management of GI complications to reduce morbidity and mortality in these patients.

Predictors and outcomes of gastrointestinal complications after cardiac surgery: A systematic review and meta-analysis

Background

In this systematic review, we aimed to examine the risk factors and surgical outcomes of gastrointestinal complications using the meta-analysis techniques.

Methods

Studies involving patients with and without gastrointestinal complications after cardiac surgery were electronically searched using the PubMed database, Cochrane Library and Scopus database, between January 2000 and May 2022. Some studies on gastrointestinal complications examined only single gastrointestinal complication (only intestinal ischemia, only gastrointestinal bleeding or only liver failure). Studies evaluating at least three different gastrointestinal complications were included in the meta-analysis to reduce the heterogeneity. Cohort series that did not compare outcomes of patients with and without gastrointestinal complications, studies conducted in a country"s health system databases, review articles, small case series (<10 patients) were excluded from the meta-analysis.

Results

Twenty-five studies (8 prospective and 17 retrospective) with 116,105 patients were included in the meta-analysis. The pooled incidence of gastrointestinal complications was 2.51%. Patients with gastrointestinal complications were older (mean difference [MD]=4.88 [95% confidence interval [CI]: 2.85-6.92]; p<0.001) and had longer cardiopulmonary bypass times (MD=17.7 [95% CI: 4.81-30.5]; p=0.007). In-hospital mortality occurred in 423 of 1,640 (25.8%) patients with gastrointestinal complications. In-hospital mortality was 11.8 times higher in patients with gastrointestinal complications (odds ratio [OR]=11.8 [95% CI: 9.5-14.8]; p<0.001).

Conclusion

The development of gastrointestinal complications after cardiac surgery is more commonly seen in patients with comorbidities. In-hospital mortality after cardiac surgery is 11.8 times higher in patients with gastrointestinal complications than in patients without.

The role of computed tomography in the diagnostic pathway of acute mesenteric ischemia: a nested case-control study

BACKGROUND

Computed tomography (CT) can be used as the primary screening modality for the evaluation of patients suspected of having acute mesenteric ischemia known to show high sensitivity and specificity rates.

PURPOSE

To prove the value of CT in patients with pathological abdominal findings following cardiac surgery.

MATERIAL AND METHODS

In a retrospective case-control study, 12 different CT scan parameters of patients with or without mesenteric ischemia following cardiac surgery were compared using univariate and logistic regression analyses.

RESULTS

Of 14,176 patients, 133 (0.9%) received an abdominal CT scan during postoperative care due to pathological abdominal findings. Sixty-eight patients were diagnosed with acute mesenteric ischemia. In-hospital mortality was 73.5% for this group. CT parameters with the highest specificity for indicating colonic ischemia were intestinal (99%) or porto-venous (96%) pneumatosis, abnormal contrast medium enhancement (89%), and occlusion of the proximal inferior mesenteric artery (81%). All of those parameters showed low sensitivity levels in the range of 15%-23%. A statistically significant association between acute mesenteric ischemia and CT appearance was obtained for contrast medium enhancement (odds ratio [OR] 12.2, 95% confidence interval [CI] 1.5-99.2) and intestinal pneumatosis (OR 21.0, 95% CI 2.7-165.2) only.

CONCLUSION

The typical CT criteria indicating mesenteric ischemia lose their accuracy in patients under critical clinical conditions. As CT remains the first-line diagnostic imaging modality for abnormal abdominal findings following cardiac surgery, negative signs should not prevent early laparotomy if clinical suspicion remains high.

Feasibility of measuring superior mesenteric artery blood flow during cardiac surgery under hypothermic cardiopulmonary bypass using transesophageal echocardiography: An observational study

Background:

Abdominal complications being rare but results in high mortality, commonly due to splanchnic organ hypoperfusion during the perioperative period of cardiac surgery. There are no feasible methods to monitor intraoperative superior mesenteric artery blood flow (SMABF). Hence, the aim of this study was to evaluate the feasibility and to measure SMABF using transesophageal echocardiography (TEE) during cardiac surgery under hypothermic cardiopulmonary bypass (CPB).

Methodology:

Thirty-five patients undergoing elective cardiac surgery under CPB were enrolled. Heart rate, mean arterial pressure (MAP), cardiac output (CO), SMABF, superior mesenteric artery (SMA) diameter, superior mesentric artery blood flow over cardiac output (SMA/CO) ratio and arterial blood lactates were recorded at three time intervals. T0: before sternotomy, T1: 30 min after initiation of CPB and T2: after sternal closure.

Results:

SMA was demonstrated in 32 patients. SMABF, SMA diameter, SMA/CO, MAP and CO decreased significantly (P < 0.0001) between T0 and T1, increased significantly (P ≤ 0.001) between T0 and T2. Lactates increased progressively from T0 to T2.

Conclusion:

Study shows that there is decrease in SMABF during CPB and returns to baseline after CPB. Hence, it is feasible to measure SMABF using TEE in patients undergoing cardiac surgery under hypothermic CPB. TEE can be a promising tool in detecting and preventing splanchnic hypoperfusion during perioperative period.

Gastrointestinal complications associated with the surgical treatment of heart disease in children

BACKGROUND/PURPOSE

The gastrointestinal system is prone to complications following heart surgery. We sought to determine the incidence and factors associated with gastrointestinal complication after cardiac surgery in children.

METHODS

A retrospective review of patients aged <16years that underwent cardiac surgery between 2009 and 2013. Primary outcome was occurrence of gastrointestinal complication within 30days. Multivariable logistic regression was performed to identify variables related to occurrence of gastrointestinal complication. Patients with gastrointestinal complication were matched with controls and postoperative lengths of stay compared.

RESULTS

Eight hundred eighty-one children underwent 1120 cardiac surgical procedures. At time of operation, 18% were neonates and 39% were infants. Cardiopulmonary bypass was used in 79%. Of 1120 procedures, 31 (2.8% [95% CI 2.0-3.9%]) had gastrointestinal complication. Necrotizing enterocolitis accounted for 61% of complications. Of patients with gastrointestinal complication, 87% survived to hospital discharge. Gastrointestinal complication was associated with preoperative co-morbidity (OR 2.2 [95% CI 1.02-4.8]) and univentricular disease (OR 2.5 [95% CI 1.1-5.5]). Neonates had the highest risk of gastrointestinal complication. Patients with gastrointestinal complications had longer hospital stays than controls (median difference, 13days [95% CI 3-43]).

CONCLUSIONS

Serious gastrointestinal complications are uncommon but associated with longer hospital stay. Neonates with univentricular disease and preoperative comorbidity are at highest risk.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

II.

Acute bowel ischemia after heart operations

Acute bowel ischemia is a perioperative complication that is frequently unrecognized as a cause of death after cardiac surgical procedures, with an in-hospital mortality of 50% to 100%. In recent years, controversy regarding the most appropriate approach to resolve clinical or laboratory suspicion and the limited therapeutic options have led to very little improvement in patient prognosis. This article reviews the related literature examining the actual prevalence, pathophysiologic mechanisms, predisposing factors, diagnostic tests, and therapeutic approaches providing a glance at new promising tools in diagnostic workup.

Postoperative abdominal complications after cardiopulmonary bypass

Background

To summarize the diagnostic and therapeutic experiences on the patients who suffered abdominal complications after cardiovascular surgery with cardiopulmonary bypass(CPB).

Methods

A total of 2349 consecutive patients submitted to cardiovascular surgery with CPB in our hospital from Jan 2004 to Dec 2010 were involved. The clinical data of any abdominal complication, including its incidence, characters, relative risks, diagnostic measures, medical or surgical management and mortality, was retrospectively analyzed.

Results

Of all the patients, 33(1.4%) developed abdominal complications postoperatively, including 11(33.3%) cases of paralytic ileus, 9(27.3%) of gastrointestinal haemorrhage, 2(6.1%) of gastroduodenal ulcer perforation, 2(6.1%) of acute calculus cholecystitis, 3(9.1%) of acute acalculus cholecystitis, 4(12.1%) of hepatic dysfunction and 2(6.1%) of ischemia bowel diseases. Of the 33 patients, 26 (78.8%) accepted medical treatment and 7 (21.2%) underwent subsequent surgical intervention. There were 5(15.2%) deaths in this series, which was significantly higher than the overall mortality (2.7%). Positive history of peptic ulcer, advanced ages, bad heart function, preoperative IABP support, prolonged CPB time, low cardiac output and prolonged mechanical ventilation are the risk factors of abdominal complications.

Conclusions

Abdominal complications after cardiovascular surgery with CPB have a low incidence but a higher mortality. Early detection and prompt appropriate intervention are essential for the outcome of the patients.

Clinico-pathological particularities of the shock-related pancreatitis

Acute pancreatitis can develop in patients with shock due to the underlying diseases, surgical interventions or because of severe hypoperfusion. The aim of our work was to study the histological alterations of the pancreas in patients dying after cardiogenic, hypovolemic or septic shock, to demonstrate the presence and severity of pancreatic injury. We performed a retrospective study which included patients who died and who were autopsied after different types of shock, hospitalized between 2007-2009 in general and cardiac intensive care units. We excluded the patients with known pancreatic diseases. From 223 patients included in our study 39 presented necrotising hemorrhagic alteration of the pancreatic tissue. There were no differences in histological and immunohistochemical findings between the different etiopathogenetic types of shock. None of the patients had characteristic clinical signs for acute pancreatitis. The digestive symptoms, they presented, could be related to the underlying disease or to postoperative state. The common findings in these patients were prolonged and severe hypotension, associated renal dysfunction, leucocytosis, hyperglycemia and hypocalcemia. Pancreatitis can occur in patients with shock, due to prolonged hypoperfusion of the pancreas. It is difficult to diagnose it because clinical signs are altered due to severity of underlying disease or analgo-sedation commonly used in intensive care. We therefore recommend in patients with shock to consider the possible development of ischemic pancreatitis for prompt and efficient treatment.

Minimized and conventional cardiopulmonary bypass damage intestinal mucosal integrity

OBJECTIVES

Previous studies have suggested that gastrointestinal integrity is compromised after cardiopulmonary bypass (CPB). We compared the effects of prolonged minimized (MCPB) and conventional CPB (CCPB) on intestinal mucosal integrity by determining mucosal damage, epithelial cell proliferation rate and distribution of tight junction proteins in a porcine model.

DESIGN

Fourteen animals were randomly assigned to undergo 240 minutes of mild hypothermic MCPB or CCPB. Ileal and colonic biopsies were obtained prior and at the end of CPB. Mucosal damage was determined under light microscopic evaluation. Immunohistochemistry was used to investigate epithelial expression of Ki-67 as a measure of cell proliferation rate and claudin-1, 2, 3, 4, 5, and 7 as elements of tight junctions.

RESULTS

In colonic biopsies, independent of the circuit type used, moderate mucosal damage was observed as indicated by focal epithelial damage, increased epithelial cell proliferation and decreased expression of tight junction protein claudin-4.

CONCLUSIONS

Colonic mucosal damage was observed similarly in MCPB and CCPB. Based on these results, the effects of MCPB on intestinal mucosal stability are similar to those of CCPB.

Salmonella sepsis simulating gastrointestinal ischaemia following cardiopulmonary bypass

Cardiac surgery is commonly associated with gastrointestinal complications. The incidence of severe abdominal pathology ranges from 0.5% to 3% and is associated with a 30% risk of mortality. Frequently occurring complications include splanchnic infarction, perforated bowel, pancreatitis, upper intestinal bleeding and diverticulitis. Systemic and localised infections are also common after open heart surgery. Plasma proteins, neutrophils, monocytes, endothelial cells and lymphocytes are all altered by cardiopulmonary bypass (CPB). Cell mediated immunity is depressed following exposure to the extra-corporeal circuit leading to an increased susceptibility and vulnerability to pathogens. Typhoid fever is the systemic manifestation of Salmonella typhi septicaemia. Its presentation can be similar to that of abdominal ischaemia making the diagnosis of this potentially fatal multi-systemic illness challenging. We report a fatal case of salmonella septicaemia convincingly masquerading as mesenteric ischaemia following routine CPB.

Case control study of gastrointestinal complications after cardiopulmonary bypass heart surgery

Background: Gastrointestinal complications (GIC) after cardiopulmonary bypass (CPB) surgery are rare, but, nevertheless, extremely dangerous.The identification of risks for GIC may be helpful in planning appropriate perioperative management strategies. The aim of the present study was to analyze perioperative factors of GIC in patients undergoing CPB surgery. Methods: We retrospectively analysed 206 patients who underwent GIC after cardiopulmonary bypass surgery from 2000 to 2007 and compared them with 206 matched control patients (matched for surgery, temperature, hemodilution and date). Univariate analysis and multiple logistic regression analysis were performed on 12 risk factors. Result: Sex and types of cardioplegia perfusate did not significantly influence the GIC after CPB surgery. Multiple logistic regression revealed that CPB time, preoperative serum creatinine (PSC) ≥ 179 mg/dL, emergency surgery, perfusion pressure ≤40mmHg, low cardiac output syndrome (LCOS), age ≥ 61, mechanical ventilation ≥96 h, New York Heart Association (NYHA) class III and IV were predictors of the occurrence of GIC after CPB surgery. Perfusion pressure and aprotinin administration were protective factors. Conclusion: Gastrointestinal complications after CPB surgery could be predictive in the presence of the above risk factors. This study suggests that GIC can be reduced by maintenance of higher perfusion pressure and shortening the time on CPB and ventilation.

Bedside diagnostic laparoscopy to diagnose intraabdominal pathology in the intensive care unit

Introduction

Delayed diagnosis of intraabdominal pathology in the intensive care unit (ICU) increases rates of morbidity and mortality. Intraabdominal pathologies are usually identified through presenting symptoms, clinical signs, and laboratory and radiological results; however, these could also delay diagnosis because of inconclusive laboratory tests or imaging results, or the inability to safely transfer a patient to the radiology room. In the current study we evaluated the safety and accuracy of bedside diagnostic laparoscopy to confirm the presence of intraabdominal pathology in an ICU setting.

Methods

This retrospective study, carried out between January 2006 and June 2008, evaluated the diagnostic accuracy of bedside diagnostic laparoscopy performed on patients with a suspicion of ongoing intraabdominal pathology. Clinical indications for bedside diagnostic laparoscopy were: ultrasonography (US) images of gallbladder distension or wall thickening of more than 3 to 4 mm, with or without pericholecystic fluid; elevation of laboratory tests (bilirubin, transaminases, myoglobin, lactate dehydrogenase, creatine phosphokinase, gamma-glutamyltransferase); high level of lactate/metabolic acidosis; CT images inconclusive for intraabdominal pathology; or inability to perform a CT scan. Patients did not undergo bedside diagnostic laparoscopy if they presented clear indications for open surgery, coagulopathy, abdominal wall infection or high intraabdominal pressure.

Results

Thirty-two patients underwent bedside diagnostic laparoscopy (Visiport Plus, Autosuture, US), 14 of whom had been admitted to the ICU for major trauma, 12 for sepsis of unknown origin and 6 for complications after cardiac surgery. The procedure was performed on an average of eight days after ICU admission (95% confidence interval = 5 to 15 days) and mean procedure duration was 40 minutes. None of the procedures resulted in complications. Bedside diagnostic laparoscopy was diagnostic for intraabdominal pathology in 15 patients, who subsequently underwent surgery, except in two cases of diffuse gut hypoperfusion. Diagnosis of cholecystitis was obtained in seven cases: two were treated with laparotomic cholecystectomy and five with percutaneous gallbladder drainage positioning.

Conclusions

Bedside diagnostic laparoscopy represents a safe and accurate technique for diagnosing intraabdominal pathology in an ICU setting and should be taken into consideration when patient transfer to radiology or the operating room is considered unsafe, or when routine radiological examinations are not conclusive enough to reach a definite diagnosis.