Variant Anatomy of the Hepatic Vasculature: Importance in Hepatobiliary Resections.

A variant anatomy of the hepatic vasculature has a clinically significant role in hepatobiliary transplantation, resection, tumour embolisation as well as in extrahepatic abdominal surgeries involving the stomach, pancreas or gall bladder. During routine cadaveric dissection, we observed a case of unusually small calibre hepatic artery proper. An accessory hepatic artery was seen emerging from the superior mesenteric artery to the right hepatic lobe along with an accessory hepatic vein from the right hepatic lobe that drained directly into the inferior vena cava. Such accessory hepatic vessels complicate and necessitate an alteration of surgical methodology during resection of hepatic lobes. Preoperative knowledge of variant hepatic vasculature is crucial for minimising the iatrogenic injury and facilitating successful abdominal surgeries.

Congenital Partial Absence of Trapezius with Variant Pattern of Rectus Sheath.

Musculocutaneous pedicled/free flaps are an essential prerequisite for reconstructive surgery. Amongst the trunk muscles commonly harvested for flaps, the trapezius and rectus abdominis provide satisfactory coverage for cranial and trunk defects. unilateral/bilateral or partial congenital absence of trapezius muscle is well documented and may result in muscular imbalances compromising posture and limb movements. During routine cadaveric dissection, we encountered a case of bilateral partial absence of occipital part of the trapezius muscle. Concurrently, the ventral abdominal musculature displayed the aponeurosis of transversus abdominis muscle solely forming the posterior wall of the rectus sheath. These conjointly occurring anomalies advocate a compensatory strengthening of the anterior wall of rectus sheath in response to the congenital absence of occipital part of the trapezius, probably to counteract the postural instability. The present study focuses on recognition of compensatory mechanisms resulting from congenital variations as identification of such processes may prevent chronic debilitating conditions.

Unusual communications of the brachial plexus.

The knowledge of innervation of pectoral muscles is important to surgeons performing breast surgeries, axillary lymph node dissection, harvesting pectoralis major/minor for flaps, and during neurotization procedures where the pectoral nerves are particularly at risk. The present case describes the innervation of the pectoral muscles solely by a nerve trunk arising from the ansa pectoralis (AP) - the loop of medial and lateral pectoral nerves. Interestingly, there was also a communication between the AP and roots forming the median nerve. It is imperative for the operating surgeons to be aware of these rare variations in order to prevent denervation and subsequent atrophy of the pectoral musculature.

Retroportal proper hepatic artery with malrotated gut.

he celiac trunk is the artery supplying the upper abdominal organs, mainly the lower part of esophagus, stomach, parts of duodenum, liver, gallbladder, spleen and pancreas. It normally trifurcates into the left gastric artery (LGA), the common hepatic artery (CHA) and the splenic artery (SA) at the superior border of the pancreas. This 'normal variant' of the vessel has been observed in 89.8 % cadaveric dissections in the Japanese population by Chen et al. (2009). Prakash et al. (2012) reported a normally trifurcating celiac trunk in 86 % of the south Indian population. The CHA branches from the celiac trunk, forms the gastroduodenal artery (GDA) and a proper hepatic artery (PHA), which further divides distally into right and left hepatic arteries. This normal origin and branching of CHA has been observed in 52­80 % of individuals (Michels 1966; Nelson et al. 1988; Hiatt et al. 1994; Koops et al. 2004; Chen et al. 2009). In a large series of 604 selective celiac and superior mesenteric angiographies, aberrant or anomalous vasculature was reported in 20.9 % of individuals by Koops et al. (2004). This knowledge and recognition of anomalous/aberrant or accessory vasculature in the upper abdomen, occurring in about one-fifth of the population is of vital importance to the hepatico-biliary-pancreatic surgeon to avoid iatrogenic injuries and complications, as well as to the interventional radiologist performing trans-arterial chemo-ablative procedures.