False positive aortic dissection on postmortem computed tomography.

UNLABELLED: Post-mortem CT-scan (PMCT) has become increasingly useful as a diagnostic tool. However, certain normal postmortem changes may mimic the appearance of pathologic findings. We report two cases of false positive aortic dissection. METHODS: Non-contrast PMCT was performed on a sixty-four-detector row scanner. Each PMCT examination was assessed and reported by two independent radiologists. Autopsies were performed according European recommendations. CASES: In two corpses, a false positive DeBakey type I aortic dissection was detected. Autopsies confirmed that CT findings were artifactual. For each case the cause of the mistake was individually discussed and mainly based on the abnormalities observed during the autopsy. In fact, in our series (750 PMCT) a true aortic dissection was detected in two corpses during the same period. CONCLUSION: When a PMCT is performed, false positive aortic dissection can occur, which confirms the interest in combining opacification.

Cervical arterial injury after strangulation--different types of arterial lesions.

After strangulation, cervical arterial injuries (CAI) are uncommon. We report three unusual cases where strangulation induced immediate stroke. CAI were examined using brain CT scan and Doppler ultrasonography in the three cases and then by autopsy in one of the victims. One of the two victims who survived the attempted strangulation had a unilateral carotid dissection, whereas in the other victim, no arterial dissection or thrombosis was observed. As regards the deceased victim, the autopsy confirmed the bilateral dissection showed on CT scan and Doppler ultrasonic examination and revealed that both carotid arteries were dilated up to two times the normal diameter. Microscopic examination showed a major bilateral hemorrhagic dissection of the media with obliterating fibrous endarteritis lesions associated with inflammatory damage. CT scan with arteriography does not demonstrate all the different types of arterial injury, particularly atheromatous embolism, direct compression, or prolonged spasm. Thus, traditional autopsy remains an essential forensic tool after strangulation to show the type of CAI.

Post-mortem computed tomography compared to forensic autopsy findings: a French experience.

OBJECTIVES: The principal aim of our study was to establish concordance between post-mortem CT (PMCT) and forensic standard autopsy (SA) in detecting lesions according to different anatomical regions. A secondary aim was to determine the efficacy of PMCT in showing lethal lesions. METHODS: PMCTs were compared with autopsies in 236 cadavers in different contexts of death. PMCT findings were assessed by two independent radiologists. RESULTS: Concordance between PMCT and autopsy was almost perfect in showing skull, basal skull and hyoid bone fractures as well as in detecting facial, vertebral or pelvic fractures. Both examinations were discordant in demonstrating some intracranial injuries, vascular or organ wounds (more findings showed by autopsy), as well in showing free air in anatomical cavities (more findings detected by PMCT). Moreover, PMCT was effective in determining lethal lesions in the context of craniofacial trauma or after a gunshot wound. Concordance between the findings of the two radiologists was almost perfect for each type of lesion. CONCLUSION: PMCT could be considered as effective as SA in determining the cause of death in certain traumatic events. It was also effective in showing lethal lesions and could be a useful tool in reducing the number of SA. KEY POINTS: • Post-mortem CT is increasingly performed as an alternative/adjunct to formal autopsy. • More modern CT systems provide greater anatomical scope. • PMCT can usually determine the cause of most deaths following trauma. • Prospective studies are still required to establish an algorithm for forensic CT.

Suicidal sodium azide intoxication: An analytical challenge based on a rare case.

INTRODUCTION: Intentional absorption of sodium azide is exceptional but remains extremely life-threatening because death rapidly occurs when significant doses are absorbed, either due to the direct effect of sodium azide or an indirect effect due to nitric oxide, cyanide ions or hydrazoic acid production from sodium azide. CASE REPORT: The body of a laboratory assistant, was discovered by his colleagues in the laboratory, seated on a chair located near a digital computer displaying information about sodium azide. Moreover, a half empty 99% sodium azide flask was found near the corpse. The laboratory staff confirmed that the young man was still alive 5h prior to discovery. RESULTS: Postmortem examination did not show any cutaneous signs of injury due to a defensive struggle. Bilateral ungual cyanosis was observed as well as a major cerebral edema and visceral congestion on autopsy. The elevated sodium azide concentration found in the gastric sample and the amount of gastric content allowed to conclude that sodium azide intake was more than 6g which was above the lethal dose, i.e. approximately 1g. Surprisingly, no sodium azide was found either in blood and serum, or in hepatic and renal tissue samplings. However, major concentrations were observed in the gastric contents, bile and urinary samples, as well as in cardiac and cerebral tissues samples. No other toxic element was found. Therefore, the post-mortem findings, the autopsy and the analytical results suggested that the laboratory assistant died after an intentional sodium azide ingestion. CONCLUSION: Sodium azide poisoning by ingestion has to date remained extremely rare and our case highlights the extreme lability of sodium azide as it was absent in the blood, in spite of significant concentrations in stomach content and some tissues. Therefore, the necessity of multiple tissues samples during autopsy should be underlined.

A brain penetration after Taser injury: controversies regarding Taser gun safety.

We report the case of a 27 year old man who was injured by a Taser gun device which penetrated the frontal part of the skull and damaged the underlying frontal lobe. Cerebral penetration was revealed by a brain CT scan. A neurosurgical procedure was required to remove the dart from the skull and brain and the evolution was successful allowing discharge of the patient one week later. There were no additional lesions, particularly electrifying lesion, as only one probe had penetrated the skull. We also observed the length of a Taser dart is sufficient to allow brain penetration. Fortunately, no infection or neurological complication occurred following brain injury. This case study underlines the potential risk induced by the use of Taser stun gun. Although generally regarded as a safe alternative, serious injuries have however been reported and questions regarding the safety of the device still remains unresolved.

An impaired accommodation of the proximal stomach to a meal is associated with symptoms after distal gastrectomy.

OBJECTIVE: The aim of this study was to assess gastric emptying and postprandial proximal gastric tone variations depending on the presence of postoperative symptoms after Billroth II gastrectomy (BII). METHODS: A total of 16 consecutive patients were prospectively studied 10 +/- 3 months after distal gastrectomy for antral cancer. No evidence of cancer recurrence was detected at the time of the study. Ten patients were asymptomatic after surgery, whereas six patients were considered as symptomatic because of at least one weekly epigastric pain, postprandial fullness, nausea, or vomiting. The fasting fundus volume and tone, the onset of a gastric relaxation after a standard 200-kcal liquid meal, and the characteristics of this relaxation (delay of occurrence, amplitude) were determined with a barostat. Patient results were compared to normal values obtained in 12 healthy volunteers. Gastric emptying studies were performed in all patients using the C(13) acid octanoic breath test after a 250-kcal meal. RESULTS: In the patients, both fasting fundus tone (BII 7.0 +/- 0.5, controls 8.4 +/- 2.4 mm Hg) and volume (BII 108 +/- 11, controls 119 +/- 29 ml) were not different from controls. Fasting fundus tone was lower in asymptomatic patients than in symptomatic patients (6.5 +/- 0.4 vs 8.1 +/- 0.5 mm Hg, p < 0.04). Gastric relaxation was observed immediately after the meal in all asymptomatic patients as well as in controls. In contrast, gastric relaxation occurred in only two of six symptomatic patients (p < 0.01); when it occurred it was delayed by the meal and was observed only 23 +/- 1 min after food intake. When a relaxation occurred, its amplitude was higher than that observed in controls both in asymptomatic and symptomatic patients (294 +/- 21 vs 179 +/- 53 ml, p < 0.02). CONCLUSIONS: After distal gastrectomy, gastric accommodation is impaired (i.e., absent or delayed) in symptomatic patients. When relaxation exists in these patients, its amplitude is higher than in control subjects.

Gastric stimulation: influence of electrical parameters on gastric emptying in control and diabetic rats.

BACKGROUND: The aim of this study was to test the effect of different pulse frequencies and amplitudes during gastric stimulation (GS) on gastric emptying in the rat. METHODS: GS was performed in 2 groups of laparotomized rats: healthy control animals, and rats with acute diabetes. The effects of four pulse frequencies (0.5, 1, 10, 20 Hz) and three pulse amplitudes (5, 20, 40 mA) were tested. The volumes emptied from the stomach after the oro-gastric instillation of a nutrient solution were compared to those obtained in animals without GS. Intragastric pH values were assessed under basal conditions and after GS. RESULTS: In both groups, GS increased emptied volumes compared to conditions without stimulation (p < 0.05) for pulse frequencies above 0.5 Hz. Increases in pulse frequencies accelerated gastric emptying (p < 0.01) with a plateau at around 10 Hz. The increase in pulse amplitudes resulted in larger emptied volumes only when the pulse frequency was 1 Hz (p < 0.04) while the opposite effect was observed at 20 Hz (p < 0.04). The most effective combinations to enhance gastric emptying compared to baseline conditions were 10 Hz with 5 or 20 mA. The overall effect of GS on gastric emptying compared to baseline conditions without stimulation, was greater in diabetic than in controls rats (p < 0.05). During stimulation, intragastric pH values were not different from basal conditions during fasting or after a meal in control and diabetic rats. CONCLUSIONS: Although both pulse frequency and amplitude should be considered during GS, frequency appears to be the most critical point. The possibility of increasing gastric emptying by electrical stimulation in diabetic rats suggests potential clinical applications for this method.

The effect of cholecystectomy on duodenojejunal motility in humans.

We hypothesized that certain gastrointestinal symptoms following cholecystectomy could be explained by motor disturbances. To test this hypothesis, we compared pre- and post-operative motor patterns between symptomatic and asymptomatic patients after surgery to evaluate whether some motor changes could be induced by gallbladder removal and associated with symptoms. Twenty-three patients were prospectively evaluated before and 3 months after cholecystectomy. After surgery, 17 patients were asymptomatic and six were symptomatic. Duodenojejunal manometric recordings were performed for 3 h during fasting, then 3 h after a 750-kcal meal. Patient motor results were compared to those obtained in the duodenojejunum of 20 healthy controls. After surgery, only a few modifications in duodenojejunal motility were observed compared to the preoperative period. Motor changes related to cholecystectomy were increase in phase III amplitude and the absence of progressive decrease of the duodenojejunal motor response after the meal. After surgery, symptomatic patients had a lower postprandial duodenal motility index after the meal than asymptomatic patients (P < 0.03) and more frequent propagated clusters of contractions (PCCs) (P < 0.02). Preoperative motor patterns associated with postoperative symptoms were postprandial only and included a low duodenal motility index (P < 0.03), and a higher number of PCCs (P < 0.02). Removal of the gallbladder has a limited effect on duodenojejunal motility. Few motor differences existed between symptomatic and asymptomatic patients after surgery. However, a low duodenal motor response to a meal and PCCs were often associated with symptoms.

Does mechanical massage of the abdominal wall after colectomy reduce postoperative pain and shorten the duration of ileus? Results of a randomized study.

The aim of this study was to determine the effectiveness of mechanical abdominal massage on postoperative pain and ileus after colectomy. We hypothesized that parietal abdominal stimulation could counteract induced pain and postoperative ileus, through common spinal-sensitive pathways, with nociceptive visceral messages. After preoperative randomization, 25 patients (age 52 +/- 5 years) underwent active mechanical massage by intermittent negative pressure on the abdominal wall resulting in aspiration (Cellu M50 device, LPG, Valence, France), and 25 patients (age 60 +/- 6 years) did not receive active mechanical massage (placebo group). Massage sessions began the first day after colectomy and were performed daily until the seventh postoperative day. In the active-massage group, amplitude and frequency were used, which have been shown to be effective in reducing muscular pain, whereas in the placebo group, ineffective parameters were used. Visual analogue scale (VAS) pain scores, doses of analgesics (propacetamol), and delay between surgery and the time to first passage of flatus were assessed. Types and dosages of the anesthetic drugs and the duration of the surgical procedure did not differ between groups. From the second and third postoperative days, respectively, VAS pain scores (P < 0.001) and doses of analgesics (P < 0.05) were significantly lower in patients receiving active massage compared to the placebo group. Time to first passage of flatus was also significantly shorter in the active-massage group (1.8 +/- 0.3 days vs. 3.6 +/- 0.4 days, P < 0.01). No adverse effects were observed. These results suggest that mechanical massage of the abdominal wall may decrease postoperative pain and ileus after colectomy.