Pathological Features of Maternal Death From HELLP Syndrome

Summary

Hemolysis, elevated liver enzymes, low platelet count (HELLP) syndrome is a life-threatening complication of preeclampsia during pregnancy or postpartum. Serious complications occur in 12.5-65% of cases of HELLP syndrome and are associated with a maternal mortality between 1.1 and 3.4%. Despite active research for many years, the etiology of this disorder exclusive to human pregnancy has not been sufficiently clarified. In clinical practice, disseminated intravascular coagulation (DIC) is found in 4-38% of cases with HELLP syndrome. Despite the apparent correlation between the marked degree of DIC in laboratory tests and the extent of laboratory changes in HELLP syndrome and the rate of maternal complications, the manifestation of DIC is neither an initial nor a principal symptom of HELLP syndrome but rather reflects a secondary pathophysiological process of the primary disease state that can be regarded as a result of preeclampsia that was diagnosed and/or treated too late. Hepatic rupture as a sequel of subcapsular liver hematoma in the course of DIC, occurring in 1-1.8% of cases, is considered the most serious and life-threatening maternal complication in HELLP syndrome. Hepatic rupture is located predominantly in the anterior-superior region of the right hepatic lobe and can occur both antepartum and postpartum. The main autopsy findings in HELLP syndrome are petechiae and suffusions in conjunctivae, skin and on mucous and serous surfaces of internal organs, cerebral edema, signs of acute respiratory distress syndrome (ARDS), edema of the lower extremities, hyperemia of the spleen, hydropericardium, and shock kidneys. Since these findings may be initiated by a variety of underlying pathologic conditions, they are highly unspecific. In contrast, liver pathology is a hallmark in the postmortem diagnosis of HELLP syndrome. At autopsy, the liver shows a rigid consistence with yellow-brown cut surfaces and confluent hemorrhagic foci on cross-sections of the liver parenchyma and occasionally subcapsular liver hematoma or hepatic rupture. The histopathological features of hepatic alterations in HELLP syndrome are periportal hepatocellular necrosis, hemorrhages sharply demarcated by an extended fibrin network from the surrounding unaffected liver parenchyma, and leukostasis in the liver sinusoids. In the kidneys, the glomeruli are primarily affected. They are enlarged and appear bloodless as a result of obliteration of the capillary lumina by swollen, vacuolated, and occasionally foamy endocapillary cells. In most cases, two characteristic capillary loop patterns of the glomeruli can be distinguished: (a) the cigar-shaped loop type presenting elongated, stretched, and obstructed loops, and (b) the pouting loop type showing enlarged glomerular tufts filling Bowman’s space with herniation of capillary loops into the proximal tubules. Relevant to medicolegal implications of a fatal outcome of HELLP syndrome is the point that the presenting symptoms of patients are generally highly unspecific. As a result, many of the patients are initially misdiagnosed with other medical or surgical disorders such as gastroenteritis, hepatitis, pyelonephritis, appendicitis, acute fatty liver of pregnancy, (AFLP), idiopathic thrombocytic purpura, and hemolytic uremic syndrome (HUS). Delay in diagnosis or expectant management of HELLP syndrome is implicated in a considerable number of cases with fatal outcome.