Portal venous gas and pneumatosis intestinalis; radiologic signs with wide range of significance in surgery

Chemotherapy-induced pneumatosis intestinalis followed by hepatic portal venous gas. A case report

Pneumatosis intestinalis (PI) is a rare disease, and there are many theories about its pathogenesis. Hepatic portal venous gas (HPVG), is thought to occur secondary to intramural intestinal gas emboli migrating through the portal venous system via the mesenteric veins. PI accompanied by HPVG is usually a sign of bowel ischaemia and is associated with a high mortality rate. We report here, a patient with liver metastases from colorectal cancer who developed PI followed by HPVG after treatment with 5-Fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6). Timely attention and management of gastrointestinal symptoms following chemotherapy are essential in the treatment of this type of patient.

Hepatic portal vein gas detected by point of care ultrasound

Introduction

Portal venous gas is a rare finding in adults and is typically associated with underlying intestinal ischemia. Portal venous gas can be detected by a bedside point of care ultrasound (POCUS) examination in adult patients in critical care units (CCU). Findings include echogenic bubbles flowing centrifugally throughout the portal venous system.

Case presentation

We present the case of a 73-year-old female with advanced ischemic cardiomyopathy and cardiorenal syndrome who was managed in the CCU. She developed vague abdominal pain and respiratory depression requiring intubation and dialysis during her course of treatment in the CCU. Her findings were consistent with portal venous gas upon POCUS, prompting computed tomography of her abdomen and surgical consultation. She was ultimately found to have nonobstructive mesenteric ischemia.

Clinical discussion

PVG is an ominous radiological sign and reflects intestinal ischemia in up to 72% of cases. Acute mesenteric ischemia of the small bowel could be due to occlusive or nonocclusive obstruction of the arterial blood supply or obstruction of venous outflow. Nonocclusive obstruction accounts for 5% to 15% of patients with acute mesenteric ischemia.

Conclusion

With the increasing use of POCUS, critical care physicians should be aware of findings consistent with portal venous gas as a bedside tool for directing the treating physician toward an ominous diagnosis in patients with shock.

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Portal vein gas detected by point-of-care ultrasound in situations of unidentified shock indicates a high likelihood of underlying intestinal ischemia.

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Point-of-care ultrasound plays an important role in detecting the sources of surgical emergencies.

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Nonobstructive mesenteric ischemia can present with nonspecific symptoms in critically ill patients, leading to a delay in diagnosis.

Case Report: A Rare Condition of Abdominal Pain: Chemotherapy Induced Portal Vein Pneumatosis Mimicking the Bowel Necrosis

Portal vein pneumatosis is the presence of air in the portal venous system, which is one of the classic radiologic features of bowel ischemia or necrosis. However, there are several other morbidities that can have portal vein pneumatosis as a complication. This is a case of a 44-year-old man who suffered from severe abdominal pain after chemotherapy for soft tissue sarcoma of his left hip. The physical signs, laboratory findings, as well as the portal venous pneumatosis sign of the CT scan strongly indicated the probability of bowel necrosis and subjected the treatment decision of the patient finally to laparotomy. However, nothing abnormal except a segment of swollen small intestine was detected. Caution should be kept in mind when encountering a patient with suspected bowel necrosis following chemotherapy since several chemotherapeutic agents could cause portal vein pneumatosis. Diagnostic laparoscopy might be a better option for such cases.

Extensive hepatic portal venous gas and gastric pneumatosis in a cat

A 15-year-old female neutered Domestic Long Hair cat was presented for acute hematemesis. Initial diagnostic workup, including serum biochemistry panel, complete blood count and coagulation profile, was unremarkable. Abdominal ultrasound showed gastric mural thickening and non-obstructive gastric foreign material. Endoscopy was performed to remove the foreign matter and obtain biopsies. Significant abnormalities of the upper gastrointestinal (GI) tract were not noted endoscopically. Overnight, the patient required a packed red blood cell transfusion following two episodes of severe hematemesis, hypotension and collapse. Serial radiographs and ultrasound revealed hepatic portal venous gas (HPVG). Computed tomography (CT) scan confirmed massive gas accumulation within the liver and emphysematous gastritis. The patient became increasingly unstable and, given her rapid decline, humane euthanasia was elected. Gastric and duodenal histopathology showed inflammatory changes, spirochetosis and mucosal epithelial degeneration. HPVG is a rarely described finding and prognosis varies drastically depending on aetiology. To the best of our knowledge, this is the first description of portal vein gas documented on multiple imaging modalities, including CT, in a cat. The patient in this report had several potential risk factors including prior endoscopy, compromise of the intestinal barrier and evidence of gastric mural bacterial invasion.

Clinical significance of pneumatosis intestinalis - correlation of MDCT-findings with treatment and outcome

Objectives

To evaluate the clinical significance of pneumatosis intestinalis (PI) including the influence on treatment and outcome.

Method and Materials

Two radiologists jointly reviewed MDCT-examinations of 149 consecutive emergency patients (53 women, mean age 64, range 21-95) with PI of the stomach (n = 4), small (n = 68) and/or large bowel (n = 96). PI extension, distribution and possibly associated porto-mesenteric venous gas (PMVG) were correlated with other MDCT-findings, risk factors, clinical management, laboratory, histopathology, final diagnosis and outcome.

Results

The most frequent cause of PI was intestinal ischemia (n = 80,53.7 %), followed by infection (n = 18,12.1 %), obstructive (n = 12,8.1 %) and non-obstructive (n = 10,6.7 %) bowel dilatation, unknown aetiologies (n = 8,5.4 %), drugs (n = 8,5.4 %), inflammation (n = 7,4.7 %), and others (n = 6,4 %). Neither PI distribution nor extension significantly correlated with underlying ischemia. Overall mortality was 41.6 % (n = 62), mostly related to intestinal ischemia (p = 0.003). Associated PMVG significantly correlated with underlying ischemia (p = 0.009), as did the anatomical distribution of PMVG (p = 0.015). Decreased mural contrast-enhancement was the only other MDCT-feature significantly associated with ischemia (p p < 0.001). Elevated white blood count significantly correlated with ischemia (p = 0.03).

Conclusion

In emergency patients, ischemia remains the most common aetiology of PI, showing the highest mortality. PI with associated PMVG is an alerting sign. PI together with decreased mural contrast-enhancement indicates underlying ischemia.

Key Points

• In emergency patients, PI may be caused by various disorders.

• Intestinal ischemia remains the most common cause of PI in acute situations.

• PI associated with decreased mural contrast-enhancement indicates acute intestinal ischemia.

• PI associated with PMVG should alert the radiologist to possible underlying ischemia.

The prognostic factors of adult patients with hepatic portal venous gas in the ED

OBJECTIVES

This study aimed to investigate the prognostic factors of adult patients with hepatic portal venous gas (HPVG) in the emergency department (ED) to facilitate clinical decision making by emergency physicians.

METHODS

Data from adult patients with HPVG who visited our ED between December 2009 and December 2013 were analyzed. The computed tomographic scan images were reviewed, and the presence of HPVG with or without pneumatosis intestinalis (PI) was confirmed by a certified radiologist. The study end point was mortality or survival upon discharge. The factors associated with mortality were specifically analyzed with multiple logistic regression models.

RESULTS

Among the total of 50 HPVG patients, the overall mortality rate was 56%. No deaths were observed among the patients with neither shock nor PI in the ED. Shock (odds ratio, 17.02; 95% confidence interval, 3.36-86.22) and PI (odds ratio, 5.14; 95% confidence interval, 1.03-25.67) were determined to be significant predictors of patient mortality after adjusting for age and sex. The mortality of the patients with both shock and PI was very high (84%).

CONCLUSIONS

Early resuscitation should be initiated for the prevention of shock in adult patients with HPVG in the ED. To enhance the chance for survival, the prompt consultation of surgeons for emergency operations should be considered for adult ED patients exhibiting both shock and PI, which may indicate true ischemic bowel disease.

Pneumatosis Intestinalis Predictive Evaluation Study (PIPES): a multicenter epidemiologic study of the Eastern Association for the Surgery of Trauma

BACKGROUND

Pneumatosis intestinalis (PI) is associated with numerous adult conditions, ranging from benign to life threatening. To date, series of PI outcomes consist of case reports and small retrospective series.

METHODS

We conducted a retrospective multicenter study, involving eight centers, of PI from January 2001 to December 2010. Demographics, medical history, clinical presentation, and outcomes were collected. Primary outcome was the presence of pathologic PI defined as confirmed transmural ischemia at surgery or the withdrawal of clinical care and subsequent mortality. Forward logistic regression and a regression tree analysis was used to generate a clinical prediction rule for pathologic PI.

RESULTS

During the 10-year study period, 500 patients with PI were identified. Of this number, 299 (60%) had benign disease, and 201 (40%) had pathologic PI. A wide variety of variables were statistically significant predictors of pathologic PI on univariate comparison. In the regression model, a lactate of 2.0 or greater was the strongest independent predictor of pathologic PI, with hypotension or vasopressor need, peritonitis, acute renal failure, active mechanical ventilation, and absent bowel sounds also demonstrating significance. Classification and regression tree analysis was used to create a clinical prediction rule. In this tree, the presence of a lactate value of 2.0 or greater and hypotension/vasopressor use had a predictive probability of 93.2%.

CONCLUSION

Discerning the clinical significance of PI remains a challenge. We identified the independent predictors of pathologic PI in the largest population to date and developed of a basic predictive model for clinical use. Prospective validation is warranted.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Portomesenteric venous gas: is gas distribution linked to etiology and outcome?

PURPOSE

To investigate various anatomical locations of portomesenteric venous gas detected by computed tomography (CT) and their relationship with the underlying etiology and the outcome.

METHODS

The study group consisted of 47 cases with evidence of portomesenteric venous gas detected on abdominal CT examinations, 12 cases were identified through a retrospective PACS search, 35 were prospectively included. The presence of gas at specific anatomical locations in the portomesenteric venous vasculature was assessed according to a pre-defined classification: the arcade vessels close to the bowel segments followed by segmental vessels, the superior mesenteric vein, the extra- and intrahepatic portal vein. The etiology of portomesenteric venous gas and its prognosis were assessed by review of surgical reports, histopathology and medical records. Surgery was performed on 30 patients.

RESULTS

Overall 68.1% of cases were of ischemic etiology. Gas present in the arcade vessels was the best indicator for ischemia (sensitivity 93.8%; specificity 70.0%, positive predictive value 90.9%, negative predictive value 77.8%) compared to other locations and the mere presence of portomesenteric gas independent from the location. The overall mortality rate was 53.2%. Only gas in the arcade and segmental vessels were associated with considerably higher mortality rates (65.8% and 75.0%, respectively) and acceptable frequency (occurrence in 80.9% and 59.6%, respectively).

CONCLUSIONS

The study results indicate that the presence of gas at specific anatomical locations in the portomesenteric venous system, namely the arcade and segmental vessels, may serve as strong indicator for ischemic etiology and poor prognosis in the assessment of individual cases.