Fatal gastric volvulus: forensic pathology considerations and postmortem CT findings

Our case series illustrates that gastric volvulus can present itself to forensic pathology services in several ways. Although rare, it should be in the differential diagnosis of a sudden and unexpected death at home, especially when scene examination or clinical history indicates recent onset of repetitive and severe vomiting. Due to its challenging clinical diagnosis, presentations also include emergency department admissions, especially when death precedes radiological imaging. A special subset of cases may also be post-procedural or post-operative, in which the diagnosis may be established ante-mortem, although a post-mortem examination should still be considered to detect post-surgical or anaesthetic complications.

Our report is the first to present and summarise the post-mortem radiology findings in a series of gastric volvulus. Overall, PMCT proved to be an important, if not essential, diagnostic adjunct in all our cases. Its major benefit was its ability to readily identify the altered epigastric and thoracic anatomy, thereby enabling the pathologist to plan the dissection. PMCT was also helpful to determine the type of volvulus. Clinical literature indicates that strangulation of the stomach is more common in organoaxial volvulus [1], which would suggest that this type of volvulus is more likely to lead to severe complications. In our series, all volvulus that were still present at post-mortem examination were of the organoaxial type, and these were all associated with sudden and unexpected death.

In line with clinical radiology features [13, 14], gastric volvulus on PMCT is characterised by an abnormally orientated stomach, often but not universally in a hiatus hernia, with evidence of severe gastric obstruction i.e. large volume gastric and sometimes oesophageal dilatation proximally, and a collapsed distal gastric and/or duodenal lumen. The stomach and/or adjacent mesenteric vessels may have a “waisted” or “whorl” appearance. PMCT can also help identify complications, such as perforation and displacement of thoracic organs. However, other essential features such as ischemia of the gastric mucosa or aspiration pneumonia require autopsy and histological confirmation for its diagnosis. Due to the complex altered anatomy, help from a radiologist with experience in post-mortem imaging is advised to interpret the images.

By definition, gastric volvulus implies a complex altered anatomy that may have superimposed surgical treatment. Spontaneous resolution prior to death may complicate matters further. These challenges mandate careful dissection and examination to fully understand the type, severity, and complications of the volvulus. For pre-operative cases, the following recommendations are based on our experience:

If gastric volvulus is suspected prior to the autopsy, re-familiarising oneself with its classification, causes, and complications will greatly reduce confusion during the dissection.

It is not recommended to mobilise organs or perform any dissection before the anatomy is fully appreciated and understood. In particular, deflating the stomach or opening the diaphragm in the anterior midline may spontaneously resolve the volvulus, precluding further examination of its anatomy.

Whether the rotation is organoaxial or mesenteroaxial can be determined relatively easily by following the great curvature of the stomach and tracking any torsion that is present. The greater and lesser omentum are also helpful anatomical landmarks. Separate organs such as the liver, lungs, and heart can be removed for better visualisation, especially when there is a large intra-thoracic component.

Once the anatomy of the volvulus is appreciated, the volvulus can usually be resolved by infero-lateral traction on the greater curvature or omentum. Alternatively, opening the diaphragm in the anterior midline will release a gastric volvulus through a diaphragmatic hernia.

Major complications such as necrosis or perforation of the gastric or colonic mucosa are usually readily recognisable at autopsy. However, histology is essential to confirm complications such as aspiration pneumonia, pancreatitis [15, 16], or necrosis of peri-oesophageal tissues. Fibrosis of the latter may indicate previous strangulation due to chronic volvulus.

In peri- and post-surgical cases, the dissection and interpretation of findings are further complicated by treatment effects and its possible complications. Depending on the extent of surgical intervention, the volvulus may be entirely resolved, and death may be essentially unrelated to the gastric volvulus. Clinical and surgical notes are essential to satisfactorily understand these cases.

Toxicology was requested in two of our cases but was not contributory in either. This supports the notion that, ordinarily, the effects of gastric volvulus explain death without contributing factors. Depending on the context of the case, the exclusion of a toxicological contribution to death may however still be required.

Post-mortem biochemistry is generally considered difficult to interpret, but elevated levels of C-reactive protein (CRP), sodium, chloride, urea, and creatinine may help to examine the respective contributions of systemic inflammation, dehydration, vomiting, and renal impairment to the mechanism of death. For instance, in our first two cases, both presenting as sudden and unexpected death, the biochemical results suggested contributions of renal impairment and systemic inflammation. In peri-operative deaths, suspected anaphylaxis may prompt testing for tryptase.

Literature suggests that gastric necrosis and ischemia are the main complications of gastric volvulus [1, 3, 17], but in our series, aspiration pneumonia was an important mechanism by which death occurred. In all our cases that presented as unexpected death at home, severe dilatation of the proximal stomach was noted, furthermore illustrating the risk of massive and lethal aspiration that gastric volvulus carries. Ischemic necrosis of the gastric mucosa was noted in two of our cases, with one further complicated by perforation, peritonitis, and massive mucosal haemorrhage.

A less commonly known complication of gastric volvulus is the displacement of intrathoracic organs, possibly limiting respiration and cardiac output. The known relation between kyphoscoliosis and gastric volvulus is especially relevant in this regard, since these individuals carry a higher risk of gastric volvulus, whilst having a more restricted thoracic cavity [5, 7, 18]. In three of our cases, a substantial intrathoracic portion of the volvulus was noted, with the potential to substantially compromise (cardio)respiratory function. One of these had kyphoscoliosis. Our second case illustrates that the mass effect of the distended, fluid-filled stomach may be compounded by the intra-thoracic presence of other structures, such as the mesentery or colon. Fluid shifts and electrolyte disturbances are more difficult to appreciate at post-mortem but are mentioned as potential complications in a clinical context [1]. Especially in cases of severe vomiting and/or rapid intermittent volvulus, dehydration and electrolyte disturbances are hypothetically relevant.

Our fourth case illustrates that the abovementioned complications may also extend into the post-operative period. A similar case was described by Sleiwah et al. [17]. Peri- and post-operative cases can also include a variety of surgical and anaesthetic complications. In our series, only aspiration at anaesthetic induction was noted, but other complications should nonetheless be considered in all peri- and post-operative deaths. Such complications include anastomosis leaks, vascular injury, ischaemia, infection, drug effects, and anaphylaxis.

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