PREVALENCE OF HEPATIC ARTERIAL VARIATIONS WITH IMPLICATIONS IN PANCREATODUODENECTOMY.

BACKGROUND: Pancreaticoduodenectomy is the usual surgical option for curative treatment of periampullary cancer and carries a significant mortality. Arterial anomalies of the celiac axis are not uncommon and might lead to iatrogenic lesions or requiring arterial resection/reconstruction in a pancreatoduodenectomy. AIM: Determine the prevalence of arterial variations having implications in pancreatoduodenectomy. METHODS: Celiac trunk and hepatic arterial system anatomy was retrospectively evaluated in 200 abdominal enhanced computed tomography studies. RESULTS: Normal anatomy of hepatic arterial system was found in 87% of cases. An anomalous right hepatic artery was identified in 13% of cases. In 12 cases there was a substitute right hepatic artery arising from superior mesenteric artery and in two cases an accessory right hepatic artery with similar origin. A hepatomesenteric trunk was identified in seven cases and in five there was a right hepatic artery directly from the celiac trunk. All cases of anomalous right hepatic artery had a route was behind the pancreatic head and then, posteriorly and laterally, to the main portal vein before reaching the liver. CONCLUSIONS: Hepatic artery variations, such as anomalous right hepatic artery crossing posterior to the portal vein, are frequently seen (13%). These patients, when undergoing pancreatoduodenectomy, may require a change in the surgical approach to achieve an adequate resection. Preoperative imaging can clearly identify such variations and help to achieve a safer pancreatic head dissection with proper surgical planning.

Prevalence of hepatic arterial variations with implications in pancreatoduodenectomy / Prevalência de variações arteriais hepáticas com implicações em pancreatoduodenectomia

ABSTRACT Background: Pancreaticoduodenectomy is the usual surgical option for curative treatment of periampullary cancer and carries a significant mortality. Arterial anomalies of the celiac axis are not uncommon and might lead to iatrogenic lesions or requiring arterial resection/reconstruction in a pancreatoduodenectomy. Aim: Determine the prevalence of arterial variations having implications in pancreatoduodenectomy. Methods: Celiac trunk and hepatic arterial system anatomy was retrospectively evaluated in 200 abdominal enhanced computed tomography studies. Results: Normal anatomy of hepatic arterial system was found in 87% of cases. An anomalous right hepatic artery was identified in 13% of cases. In 12 cases there was a substitute right hepatic artery arising from superior mesenteric artery and in two cases an accessory right hepatic artery with similar origin. A hepatomesenteric trunk was identified in seven cases and in five there was a right hepatic artery directly from the celiac trunk. All cases of anomalous right hepatic artery had a route was behind the pancreatic head and then, posteriorly and laterally, to the main portal vein before reaching the liver. Conclusions: Hepatic artery variations, such as anomalous right hepatic artery crossing posterior to the portal vein, are frequently seen (13%). These patients, when undergoing pancreatoduodenectomy, may require a change in the surgical approach to achieve an adequate resection. Preoperative imaging can clearly identify such variations and help to achieve a safer pancreatic head dissection with proper surgical planning.

RESUMO Racional: Pancreatoduodenectomia consiste no procedimento cirúrgico usual para tratamento curativo de neoplasias periampulares e apresenta mortalidade significativa. Variações arteriais do tronco celíaco não são incomuns e podem favorecer lesões iatrogênicas ou exigirem realização de ressecção/reconstrução arterial durante pancreatoduodenectomia. Objetivo: Determinar a prevalência de variações arteriais que apresentam implicações durante pancreatoduodenectomia. Métodos: A anatomia do tronco celíaco e sistema arterial hepático foi investigada retrospectivamente em 200 exames tomográficos contrastados do abdome. Resultados: Anatomia normal do sistema arterial hepático foi observada em 87% dos casos. Presença de uma artéria hepática direita anômala foi identificada em 13%. Em 12 casos houve uma artéria hepática direita substituta originária da artéria mesentérica superior, em dois uma artéria hepática direita acessória com origem similar. Tronco hepaticomesentérico foi identificado em sete casos e em cinco houve uma artéria hepática direita originária diretamente do tronco celíaco. Em todos casos de artéria hepática direita anômala seu curso foi por trás da cabeça do pâncreas e com trajeto passando posteriormente ao tronco da veia porta e após percorrendo sua face lateral direita antes de alcançar o fígado. Conclusões: Variações arteriais hepáticas, como artéria hepática direita anômala com trajeto posterior à veia porta, são frequentes (13%). Nestes pacientes, quando submetidos à pancreatoduodenectomia, pode ser necessária alteração na abordagem cirúrgica para ressecção adequada. Exames de imagem pré-operatórios podem claramente identificar estas variações e auxiliar na realização de dissecção segura da cabeça do pâncreas com adequado planejamento cirúrgico.

Extreme liver resections with preservation of segment 4 only.

AIM: To evaluate safety and outcomes of a new technique for extreme hepatic resections with preservation of segment 4 only. METHODS: The new method of extreme liver resection consists of a two-stage hepatectomy. The first stage involves a right hepatectomy with middle hepatic vein preservation and induction of left lobe congestion; the second stage involves a left lobectomy. Thus, the remnant liver is represented by the segment 4 only (with or without segment 1, ± S1). Five patients underwent the new two-stage hepatectomy (congestion group). Data from volumetric assessment made before the second stage was compared with that of 10 matched patients (comparison group) that underwent a single-stage right hepatectomy with middle hepatic vein preservation. RESULTS: The two stages of the procedure were successfully carried out on all 5 patients. For the congestion group, the overall volume of the left hemiliver had increased 103% (mean increase from 438 mL to 890 mL) at 4 wk after the first stage of the procedure. Hypertrophy of the future liver remnant (i.e., segment 4 ± S1) was higher than that of segments 2 and 3 (144% vs 54%, respectively, P < 0.05). The median remnant liver volume-to-body weight ratio was 0.3 (range, 0.28-0.40) before the first stage and 0.8 (range, 0.45-0.97) before the second stage. For the comparison group, the rate of hypertrophy of the left liver after right hepatectomy with middle hepatic vein preservation was 116% ± 34%. Hypertrophy rates of segments 2 and 3 (123% ± 47%) and of segment 4 (108% ± 60%, P > 0.05) were proportional. The mean preoperative volume of segments 2 and 3 was 256 ± 64 cc and increased to 572 ± 257 cc after right hepatectomy. Mean preoperative volume of segment 4 increased from 211 ± 75 cc to 439 ± 180 cc after surgery. CONCLUSION: The proposed method for extreme hepatectomy with preservation of segment 4 only represents a technique that could allow complete resection of multiple bilateral liver metastases.