Inferior Hepatic Fissures: Anatomic Variants in Trinidad and Tobago.

Classic descriptions of the visceral surface of the human liver only define three fissures: transverse, sagittal and umbilical fissures. Any additional fissures that are present on the visceral surface of the liver are considered variant inferior hepatic fissures (IHFs). This study was carried out to document the prevalence of IHFs in the Eastern Caribbean. Knowledge of these variants is important to clinicians who treat liver disorders in persons of the Caribbean diaspora. In this study, two independent researchers observed all consecutive autopsies performed at the facility over a period of 10 weeks. They examined the visceral surface of the unfixed liver in situ. Any specimen with variant IHFs was selected for detailed study. We documented the relation of the variant IHFs to nearby viscera and then explanted the livers using a standardized technique. The following details were recorded for each liver: number, location, depth, length, and width of IHFs. All measurements were checked independently by two researchers and the average measurement was used as the final dimension. Each liver was then sectioned in 1 cm sagittal slices to document the relationship of intraparenchymal structures. We observed 60 consecutive autopsies in unselected cadavers. Variant IHFs were present in 21 (35%) cadavers at a mean age of 68.25 years (range: 61 - 83; median 64.5; standard deviation (SD) ± 8.45). The variants included a deep fissure in the coronal plane between segments V and VI in 19 (31.7%) cadavers (related to the right branch of the portal vein in 63.2% of cases), a well-defined segment VI fissure running in a sagittal plane in four (6.7%) cadavers, a well-defined fissure incompletely separating the caudate process from the caudate lobe proper in five (8.3%) cadavers, a consistent fissure that arose from the left side of the transverse fissure and coursed between segments II and III in three (5%) cadavers, and a deep coronal fissure dividing the quadrate to form an accessory quadrate lobe in one (1.7%) cadaver. Almost one in three unselected persons in this population have anatomically variant fissures on the visceral surface of the liver. The variants include Rouvière's sulci (31.7%), caudate notches (8.3%), segment VI fissures (6.7%), left medial segment fissures (5%), and quadrate fissures (1.7%). The clinical relevance of these variants is discussed. Any clinician treating liver diseases in persons of Caribbean extract should be aware of their presence.