A case with hepatic portal vein gas who required delayed elective surgery

Highlights • Hepatic portal venous gas (HPVG) is believed to be an indication for emergent surgery because it is associated with high mortality rate.• The recent increase in the use of modern abdominal CT has resulted in the detection of HPVG in more benign conditions.• The decision-making process whether we choose emergent surgery or conservative treatment without surgery is important for the patients with HPVG.• The case with portal hepatic vein gas (HPVG) presented in this article required delayed elective surgery after conservative treatment.• This case show the subtle difference comparing with the other case who were successfully treated without surgery.


Introduction
The presence of hepatic portal venous gas (HPVG) had previously been considered to reflect abdominal severe events, such as intestinal necrosis that required emergent surgery and associated with a high mortality rate [1]. However, the recent increase in the use of modern abdominal CT has resulted in the detection of HPVG in more benign conditions [2]. As a result, there are many reports of patients with HPVG who recovered after conservative treatment [3]. Indeed, in 1978, a review of early studies of HPVG found that HPVG was associated with a mortality rate of 75%, while a survey in 2001 revealed that the overall mortality rate was 39% [4].
The decision-making process whether to choose emergent surgery or conservative treatment without surgery is important for the patients with HPVG. The case presented in this article required delayed elective surgery after conservative treatment show subtle differences in clinical finding and laboratory data from cases who were successfully treated without surgery or cases required emergent surgery. We would like to compare the clinical data of the other 17 cases in our hospital to focus on the subtle differences of clinical finding of this case. This work has been reported in line with the SCARE criteria [5].

Case presentation
An 84-year-old male had visited to a hospital due to the sudden onset of abdominal pain. He had developed massive hepatic portal vein gas on emergent CT and referred to our hospital. He had been treated for the cerebral infarction and atrial fibrillation, and had history of inguinal hernia repair and appendectomy. Physical finding at administration showed slight distension and tenderness of lower abdomen but no tenderness. Vital signs were stable with 130/84 mmHg of blood pressure, 71/min of pulse rate and 36.9 • C of body temperature. Laboratory data showed as follows; white blood cell (WBC) 13,300/l, c-reactive protein (CRP) 37 mg/dl, base excess   II) score was calculated as 17. Enhanced CT on admission revealed hepatic portal vein gas in whole liver and intestinal pneumatosis at ileum ( Fig. 1A and B). We decided to make conservative therapy with heparinization without emergent surgery. The CT on the next day showed small HPVG remained at lateral segment and increased ascites. Intestinal pneumatosis was distinguished and symptoms were improved. Feeding was started on 5 th day after onset and he was discharged on 9 th day. However, he was suffered from right lower abdominal pain and vomiting and admitted our hospital on 23th day (Fig. 2).
CT revealed thickness of intestinal wall which was a same portion of intestinal pneumatosis and fluid collection in oral intestine ( Fig. 3A and B). We decided to perform laparotomy under the diagnosis with bowel obstruction and made partial resection of ileum. The resected ileum was 40 cm of length and had segmental stenosis at three portions (Fig. 4). Pathologic diagnosis was an ischemic intestinal stenosis. Clinical course after the operation was no eventful.

Discussion
The exact etiology of hepatic portal venous gas (HPVG) is still unclear, because only a small number of case reports and systematic reviews are available [1,2,6]. HPVG was first reported by Wolfe and Evance in 1955 [7]. In general, HPVG is caused by intestinal ischemia, but several reports have discussed the development of HPVG in patients with other non-ischemic conditions including ulcerative colitis [8], Crohn's disease [9], enteritis [10] cholangitis [11,12], neobladder obstruction [13] and gastric ulcer [4].
We treated 18 cases with HPVG from January, 2014 to January, 2017, which were divided into four groups according to the severity of HPVG: alive without surgery, alive after elective surgery, alive after emergent surgery; and dead with/without emergent surgery (Table 1). Emergent surgery was required for 6 cases (30%) and two cases died 33 and 46 operative days. While 11 cases (61%) were recovered without surgery. Obvious difference of APCHE II score was seen between cases required emergent surgery and recovered    Indeed, the utility of APACHE II score for determining the treatment for HPVG [14], and correlation with the prognosis of patients who require intensive care [15,16] were reported. Thus, this score, which assesses the whole body condition, could be useful for selecting surgery or conservative treatment [14,17,18].
Most of our cases were associated with intestinal ischemia, which was indicated by the CT finding of intestinal ischemia and mesenteric vein gas or intestinal pneumatosis. If we missed these findings, a correct diagnosis would have been difficult to make.
The role of CT in predicting the prognosis of HPVG has been reported, in a study that emphasize the importance of the extent of hepatic portal gas and the existence of intestinal pneumatosis were emphasized [19]. In addition, we would like to recommend followup CT after a few days seems to be most useful for the management for HPVG. We could find a change of CT finding for 6 cases including presented case (Table 2). Presented case is only one case whose follow up CT showed remained portal hepatic gas, in contrast with other cases whose portal hepatic gas was distinguished at CT on 1-3 days after the onset. When the physical findings associated with the need for emergent surgery are not observed, HPVG or mesenteric vein gas quickly disappeared in a few days.
In summary, presented case was an only one who required elective surgery among 18 cases with HPVG in our experience. This case had subtle differences of clinical findings apart from the other cases. The APACHE II Score was slightly elevated and the PHVG was remained at follow up CT on the next day after onset comparing with the other case who were successfully treated without surgery.
We hope the clinical finding of this case required delayed elective surgery will help the physician's decision-making process for HPVG.

Conclusions
The case presented in this article required delayed elective surgery after conservative treatment show the subtle difference comparing with the other case who were successfully treated without surgery. The APACHE II Score was slightly elevated and the PHVG was remained at follow up CT on the next day after the onset. We hope this report will help the physician's decision-making process for HPVG.

Sources of funding
We did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Ethical approval
The case report was approved by the institutional review board at Yamanashi Prefectural Central Hospital.

Consent
Written Informed Consent was obtained from the patient for publication of this case and any accompanying images. A copy of the written consent is available for review by the Editorial-in-Chief of this journal.

Author contribution
KI, TI, KF, HN, YO, and MO conceived of this case presentation and drafted the manuscript. AT, HW, TN, HN, KM, HM, MY, MI and HM participated in the treatment of this case. All authors read and approved the final manuscript.

Registration of research studies
This is mandatory for human studies only. We obtained written informed consent by the patients, concerning this publication.
We attached the copy of the written informed consent. I obtained UIN "researchregistry5139".

Guarantor
Hiroshi Nakagomi and Masao Omata have accept full responsibility for this work and controlled the decision to publish.

Provenance and peer review
Not commissioned, externally peer-reviewed.

Declaration of Competing Interest
The authors declare no conflicts of interest.