Pneumatosis intestinalis in abdominal CT: predictors of short-term mortality in patients with clinical suspicion of mesenteric ischemia

Combining clinical and radiological features improves prediction of bowel ischemia in patients with CT findings of pneumatosis intestinalis

BACKGROUND

Pneumatosis intestinalis on CT presents a diagnostic dilemma, because it could reflect bowel ischemia or benign finding.

PURPOSE

To determine radiological and clinical features that can predict bowel ischemia in patients with pneumatosis intestinalis on CT.

MATERIALS AND METHODS

Patients with "pneumatosis" in abdominal CT reports performed between 1/1/2002 and 12/31/2018 were retrospectively included. Pneumatosis intestinalis was confirmed by review of images. Radiological features of pneumatosis, laboratory data, clinical signs and symptoms were collected. Pathologic pneumatosis intestinalis (PPI) was defined as presence of ischemic (viable or dead) bowel on surgery or death during admission or within 30 days of discharge due to ischemia. Univariate statistical analysis was used to identify features associated with PPI, followed by multivariate logistic regression models.

RESULTS

A total of 313 consecutive patients with pneumatosis intestinalis (162 (52%) men, median age 67 years, IQR 55-78 years) were included. Pathologic pneumatosis intestinalis was present in 114/313 (36%) patients. Presence of arterial or venous thrombosis, porto-mesenteric gas, fat stranding, and location in the small bowel were significantly associated with PPI. A combined clinical and radiological model, which included age, WBC, creatinine, abdominal distention, rebound or guarding, shock, presence of porto-mesenteric gas and fat stranding showed an AUC of 0.85 for prediction of PPI, higher than models using clinical (AUC = 0.80, p = 0.005) or radiological factors (AUC = 0.80, p < 0.0001) alone.

CONCLUSION

Improved prediction of pathological pneumatosis intestinalis can be achieved by a model incorporating both clinical and radiological features (AUC = 0.85)rather than by either clinical (AUC = 0.80) or radiological (AUC = 0.80) features alone.

CT evaluation of bowel wall enhancement in pneumatosis intestinalis: preventing non-therapeutic laparotomies

PURPOSE

To evaluate the diagnostic performance of bowel wall enhancement for diagnosing concomitant bowel ischemia in patients with parietal pneumatosis (PI) diagnosed at abdominal CT.

MATERIALS AND METHODS

From January 1, 2012 to December 31, 2021, 226 consecutive patients who presented with PI on abdominal CT from any bowel segment were included. Variables at the time of the CT were retrospectively extracted from medical charts. CT examinations were blindly analyzed by two independent radiologists. The third reader classified all disagreement of bowel enhancement in three categories: (1) normal bowel enhancement; (2) doubtful bowel wall enhancement; (3) absent bowel wall enhancement. Multivariable logistic regression analysis was performed. Concomitant bowel ischemia was defined as requirement of bowel resection specifically due to ischemic lesion in operated patients and death from bowel ischemia in non-operated patients.

RESULTS

Overall, 78/226 (35%) patients had PI associated with concomitant bowel ischemia. At multivariate analysis, Only absence or doubtful bowel wall enhancement was associated with concomitant bowel ischemia (OR = 167.73 95%CI [23.39-4349.81], P < 0,001) and acute mesenteric ischemia associated with PP (OR = 67.94; 95%CI [5.18-3262.36], P < 0.009). Among the 82 patients who underwent a laparotomy for suspected bowel ischemia, rate of non-therapeutic laparotomy increased from 15/59 (25%), 2/6 (50%) and 16/17 (94%) when bowel wall enhancement was absent, doubtful and normal respectively.

CONCLUSION

Absence of enhancement of the bowel wall is the primary feature associated with concomitant bowel ischemia. It should be carefully assessed when PI is detected to avoid non-therapeutic laparotomy.

Hepatic venous gas secondary to pulmonary barotrauma: rat model study

Intrahepatic gas (IHG) is commonly observed during early postmortem examinations of humans with upper or lower airway obstructions. We conducted a study to test the hypothesis that intrapulmonary gas could retrogradely spread to the hepatic vein following pulmonary barotrauma (PB). To establish a rat model of pulmonary barotrauma, we utilized a controllable pressure-vacuum pump to apply airway pressure (40, 60, or 80 mmHg). The rats were dissected directly at the end of the experiment, and histological analysis was performed through microscopic examination of the rats. Additionally, the rats were ventilated with meglumine diatrizoate under pressures of 160 and 250 mmHg to observe the signal dynamic diffusion using X-ray fluoroscopy examination. Rats exhibited classical changes associated with PB, such as alveolar rupture, pulmonary interstitial emphysema, and hemorrhage, as well as IHG characterized by the presence of gas in the hepatic vein and hepatic sinusoids. Air emboli were not observed in the liver in any of the 40 mmHg groups. However, they were observed in the liver in the 60 and 80 mmHg groups, the amount and size of air emboli in the 80 mmHg group were greater than those in the 60 mmHg group (p < 0.05). The 80 mmHg group presented radial grape-like bubbles in the centrilobular portion of the liver accompanied by congestion in the peripheral region of the hepatic lobule. X-ray fluoroscopy examination revealed a gradual enhancement of dynamic contrast medium signals from the lung to the inferior vena cava and then to the liver. Our findings indicate that pulmonary barotrauma can lead to the retrograde spread of intrapulmonary gas to the hepatic vein. When it is clear that no decomposition of the body has occurred, the presence of IHG serves as a novel indicator for the diagnosis of obstructive pulmonary disease or obstruction in the upper or lower airway.

Probabilistic Prediction of Gastrointestinal Ischemia after Cardiothoracic Surgery

BACKGROUND

 Gastrointestinal ischemia (GIisch) is challenging to diagnose in patients after cardiothoracic surgery. Computed tomography angiography (CTA) carries substantial false-negative and false-positive rates. The aim of the study was to evaluate if a combination of readily available variables improves the diagnosis of GIisch after cardiothoracic surgery.

METHODS

 This retrospective study included patients receiving intensive care after cardiothoracic surgery. GIisch was confirmed by surgical and/or endoscopic findings. A GIisch prediction score was developed using the Spiegelhalter-Knill-Jones system in a training cohort then tested in a validation cohort (patients without obvious signs of GIisch on CTA).

RESULTS

 The training cohort comprised 125 consecutive patients with suspected GIisch in 2008 to 2019, including 85 with confirmed GIisch. CTA, performed in 92 patients, had a high false-negative rate of 17/60 (28%) and a lower false-positive rate of 7/32 (22%). The score included cardiopulmonary bypass, negatively associated with GIisch, and six variables positively associated with GIisch: intraoperative mean arterial pressure < 50 mm Hg, aspartate aminotransferase > 15 N, lactate increase in 24 hour > 20%, and 3 CTA findings, namely, bowel dilation, bowel wall thickening, and mesenteric vasoconstriction. The area under the receiver operating characteristic was 0.82 (95% confidence interval [CI], 0.51-0.93) in the training cohort and 0.82 (95% CI, 0.68-0.96) in the validation cohort (n = 34 patients). Reliability of the predicted probabilities was greatest for probabilities ≤ 30% or ≥ 70%.

CONCLUSION

 In patients receiving intensive care after cardiothoracic surgery, GIisch cannot be ruled out based solely on CTA findings. A scoring system combining CTA findings with other variables may improve the diagnosis of GIisch in this population.

Association of Pneumatosis Intestinalis With Surgical Outcomes and Mortality: A Matched, Retrospective Cohort Study and Literature Review

Background

To determine the clinical importance of pneumatosis intestinalis (PI) on surgical decision-making and patient outcomes.

Methods

A matched cohort observational study was conducted including all clinical encounters for both ambulatory and inpatient care at UCLA Health between February 15, 2006 and January 31, 2023. Patients were initially identified using encounter diagnostic codes for "other specified diseases of intestine." A radiologic diagnosis of PI was then assessed using natural language processing techniques followed by confirmation using manual chart review. Patients who did not have PI served as a control group. Patient comorbidity was assessed using Elixhauser comorbidity scores. Logistic regression and Cox hazard analyses were used to assess associations between PI and mortality. The main outcome was 90-day all-cause mortality. Secondary outcomes were the proportion of patients undergoing surgery and, of those, how many required bowel resections.

Results

Of the 16,728 patients identified by diagnostic coding, 315 were confirmed to have a diagnosis of PI. The 90-day mortality rate for all patients with PI was 29%. Surgery was performed for 62 patients (20%), of whom 46 (72%) underwent bowel resection and 16 (28%) underwent abdominal exploration alone. Most patients underwent surgery for peritonitis (37%), bowel obstruction (31%), and/or pneumoperitoneum (23%) in association with PI; whereas only 8% of patients received surgery exclusively for PI. There was no statistically significant association between PI and mortality with logistic regression conditioned on other risk factors for mortality. In contrast, survival analysis of a matched cohort demonstrated a small effect of PI on mortality (hazard ratio = 1.24: 95% confidence interval = 1.16-1.32, P = 0.021).

Conclusions

Most patients with a diagnosis of PI survive without requiring surgery. Of those who undergo surgery, nearly all have indications for laparotomy exclusive of PI. Mortality in patients who have pneumatosis is strongly associated with comorbid disease, with little to no independent association with PI. Our findings suggest that the presence of PI should not be a primary indication for surgical intervention.

Portal venous contrast enhancement ratio of the adrenal glands and spleen as prognostic marker of mortality in patients with acute mesenteric ischemia

PURPOSE

Contrast enhancement of the adrenal gland defined by computed tomography (CT) was previously analyzed as a prognostic factor for critically ill patients in various diseases. However, no study investigated this quantitative parameter in patients with acute mesenteric ischemia. Therefore, the aim of this study was to evaluate the prognostic value of the contrast enhancement of the adrenal glands in patients with clinically suspected AMI.

METHODS

All patients with clinically suspected AMI were retrospectively assessed between 2016 and 2020. All patients underwent surgical exploration after CT imaging. Overall, 134 patients (52 female patients, 38.8%) with a mean age of 69.2 ± 12.4 years were included into the present analysis. For all patients, the preoperative CT was used to calculate the contrast media enhancement of the adrenal glands and the spleen.

RESULTS

A total of 27 patients (18.5%) died within the first 24 h and over the following 30-day 94 patients (68.6%) died. There were statistically significant differences regarding the mean values for adrenal-to-spleen ratio for 24-h mortality (p = 0.001) and 30-day mortality (p = 0.004), whereas the radiodensity of the inferior vena cava and the radiodensity of the spleen was statistically significant between survivors and non-survivors after 30 days (p = 0.037 and p = 0.028, respectively). In Cox regression analysis, mean adrenal radiodensity was associated with 24-h mortality (HR 1.09, 95% CI 1.02-1.16, p = 0.01) but not with 30-day mortality (HR 1.03, 95% CI 0.99-1.07, p = 0.13).

CONCLUSION

The contrast media enhancement of the adrenal gland is associated with the 24-h and 30-day mortality in patients with AMI. However, the prognostic relevance for translation into clinical routine needs to be validated in other cohorts.

[Pneumatosis cystoides intestinalis: a case report and literature review]

Pneumatosis cystoides was first described by Du Vernay in 1783. This is a fairly rare disease with nonspecific symptoms and CT data on pneumoperitoneum. The authors present pneumatosis intestinalis in a patient with systemic connective tissue disorder. Free gas in abdominal cavity and dilated intestinal loops were an indication for emergency surgery with subsequent resection of intestine due to signs of ischemic damage. A review of clinical cases allows us to conclude that pneumoperitoneum requires careful differential diagnosis. Free gas in abdominal cavity in patients with cystic pneumatosis is an indication for emergency surgery only in case of complicated course of disease.

Computed Tomography-Defined Body Composition as Prognostic Parameter in Acute Mesenteric Ischemia

INTRODUCTION

Body composition comprising low-skeletal muscle mass (LSMM) and subcutaneous and visceral adipose tissue (SAT and VAT) can be assessed by using cross-sectional imaging modalities. Previous analyses suggest that these parameters harbor prognostic relevance in various diseases. Aim of this study was to analyze possible associations of body composition parameters on mortality in patients with clinically suspected acute mesenteric ischemia (AMI).

METHODS

All patients with clinically suspected AMI were retrospectively assessed between 2016 and 2020. Overall, 137 patients (52 female patients, 37.9%) with a median age of 71 years were included in the present analysis. For all patients, the preoperative abdominal computed tomography (CT) was used to calculate LSMM, VAT, and SAT.

RESULTS

Overall, 94 patients (68.6%) of the patient cohort died within 30 days within a median of 2 days, range 1-39 days. Of these, 27 patients (19.7%) died within 24 h. According to the CT, 101 patients (73.7%) were classified as being visceral obese, 102 patients (74.5%) as being sarcopenic, and 69 patients (50.4%) as being sarcopenic obese. Skeletal muscle index (SMI) was lower in non-survivors compared to survivors (37.5 ± 12.4 cm2/m2 vs. 44.1 ± 13.9 cm2/m2, p = 0.01). There were no associations between body composition parameters with mortality in days (SMI r = 0.07, p = 0.48, SAT r = -0.03, p = 0.77, and VAT r = 0.04, p = 0.68, respectively). In Cox regression analysis, a nonsignificant trend for visceral obesity was observed (HR: 0.62, 95% CI: 0.36-1.05, p = 0.07).

CONCLUSION

SMI might be a valuable CT-based parameter, which could help discriminate between survivors and non-survivors. Further studies are needed to elucidate the associations between body composition and survival in patients with AMI.