What Is the Porta Hepatis?
There are three "H" -shaped grooves in the center of the liver, which are about 5cm in length. The transverse grooves are located in the center of the liver. Branches, nerves and lymphatics of the liver come in and out, so it is called the hilum. These structures that enter and exit the hepatic hilum are called pedicles by the peritoneum. The horizontal groove connecting the left and right longitudinal grooves of the visceral surface of the liver is the hepatic hilum. The hilar is divided into the first hilar, the second hilar, and the third hilar.
- Chinese name
- Hilum
- Foreign name
- Hepatic portal
- Classification
- First, second, third hilum
- Brief introduction
- The left and right longitudinal grooves connecting the dirty side of the liver
- There are three "H" -shaped grooves in the center of the liver, which are about 5cm in length. The transverse grooves are located in the center of the liver. Branches, nerves and lymphatics of the liver come in and out, so it is called the hilum. These structures that enter and exit the hepatic hilum are called pedicles by the peritoneum. The horizontal groove connecting the left and right longitudinal grooves of the visceral surface of the liver is the hepatic hilum. The hilar is divided into the first hilar, the second hilar, and the third hilar.
Anatomy of the second hepatic hilar vessels and its clinical significance
- When dealing with Budd-Chiari syndrome, hepatic trauma and lobectomy, and liver transplantation, the anatomy of the hepatic veins and inferior vena cava veins needs to be accurately grasped. The hepatic vein wall of the hepatic segment is thin, without valves, and there is little surrounding connective tissue. It is fixed in the liver parenchyma and is not easy to contract. The intraluminal pressure is 0 to 0.1 cm of water column. It shows negative pressure when inhaled. Hepatic vein injury and left triangle ligament and coronary ligament separation during surgery can sometimes tear the inferior vena cava, left hepatic vein, or left subphrenic vein, often leading to major bleeding and embolism. The portal vein system and hepatic artery system supplying the liver merge into the hepatic vein through the central vein and the sublobular vein, more than the second hepatic portal and the third hepatic portal meet the inferior vena cava. The diameter of the inferior vena cava that flows into the second hepatic hilum is relatively large, mainly including the right hepatic vein, left hepatic vein, and middle hepatic vein. Most liver blood is drained by it. Hepatic veins are the only veins that drain liver blood. When hepatic or hepatic lobes are removed, damage to the main hepatic vein trunks should be prevented to ensure adequate drainage of residual hepatic vein blood. Obstruction of hepatic vein outflow tract or poor drainage of hepatic vein in Budd-Chiari syndrome can lead to hepatic parenchymal congestion, cirrhosis or portal hypertension. When part of the hepatic vein is blocked, between the unobstructed hepatic vein and the blocked hepatic vein, the subcapsular arch of the liver and the parenchymal sinus space, the iliac vein and the hepatic vein, the hepatic vein and the short hepatic vein, the interlobular and The collateral circulation is widely formed between the perihepatic adhesion bands and the perihepatic ligaments. Studies have shown that at least one major hepatic vein can be kept open before a compensatory collateral circulation can be established between the portal vein and interlobular vein to maintain liver function, otherwise acute or explosive liver failure or acute or explosive Buga syndrome. The third hepatic hilum is a quarter of the inferior vena cava hepatic posterior segment of the right hemilateral wall bordering the liver. There are a large number of hepatic vein branches of different calibers. These small and medium veins are also called short hepatic veins. Reported as many as 30-50, if not handled properly during surgery, often lead to uncontrollable bleeding. There is often a large short hepatic vein in many short hepatic veins. This material occurs on the right posterior side of the inferior vena cava, with a diameter of (8.74-3.1) mm, which we call the right coarse trunk. Mastering these characteristics is of great significance for liver surgery, hepatic venography, manometry, and direct BCS surgery.
Key points of hilar laparoscopic hilar anatomy
The difficulty and key of laparoscopic anatomical liver resection is the dissection of the first and second hepatic hilum. Due to the good visual field and more intuitive exposure, laparoscopy is easier to complete the dissection of the first and second hepatic hilum than traditional open surgery. Laparoscopic hilar anatomical techniques are still based on traditional open hilar anatomical techniques, but they are unique. Based on the experience of 28 cases of laparoscopic anatomical hepatectomy, the author summarizes the main technical points of laparoscopic anatomy of the hilar anatomy: pre-operative analysis of CT or MRI and other imaging data to determine the vascular direction of the hepatic hilar and whether there is vascular variation. Accurate judgment of hilar anatomy during operation is an important prerequisite for successful operation. Laparoscopic surgery lacks the touch of the hand and grasps the depth, and the action is magnified, which is prone to operation errors and accidental injuries. Therefore, the action must be gentle, to avoid excessive amplitude, and it should be dissected layer by layer, from shallow to deep. Try to use an ultrasonic knife to dissect as much as possible. The dissection of the first hepatic portal starts from the left side, the hepatic artery is dissected first, and then the portal vein is dissected. When the dissection of the portal vein is difficult, it is not necessary to skeletalize, and it can be clipped. The anatomy of the blood vessels of the left half of the liver can be dissected separately at the hepatic hilum of the sagittal portion, and the blood vessels of the corresponding liver segment are clamped as required. When the anatomical structure is unclear, the suction device can be used to repeatedly push and flush, and the blunt separation can often reveal the structure gradually. Once an accidental bleeding occurs during the operation, you can use a device or gauze to temporarily compress the bleeding site to reduce bleeding, make a judgment based on the bleeding site and characteristics, and choose the correct hemostasis method under direct vision, and if necessary, block the first hepatic hilum. For difficult-to-control bleeding that occurs in the second and third hilar hilum, the abdomen should be converted in time to avoid accidents. The anatomy of the second hepatic hilum should be free of the perhepatic ligament. Care should be taken to prevent tearing of the hepatic vein. After successful isolation of the hepatic vein, pre-blocking with 1 or 2 titanium clips can be used. It should be avoided in the liver parenchyma as much as possible. External ligation cuts off the hepatic vein. The anatomy of the third hepatic hilum should follow the principle of "bottom to top, from outside to inside", with blunt separation as the main principle, and each short liver vein should be clamped and disconnected one by one. Avoid excessive pulling of the liver to cause liver damage. Short vein tear bleeding.
Laparoscopic liver resection is a high-risk and difficult operation. If you can master the laparoscopic portal anatomy technique, it will be possible to make this operation safe and easy. Because the blood vessels of the left outer lobe and the left hepatic liver travel longer outside the liver than the right liver, anatomical separation is easier under laparoscopy, which is more advantageous than traditional open surgery. Therefore, left external lobe resection may become another gold standard operation for laparoscopy.