[Abstract] Objective To investigate the clinical significance of hepatectomy under selective hemihepatic blood flow complete blockade. Methods Retrospective analysis of clinical data of 100 patients who underwent regular hepatectomy with no more than half liver for primary hepatocellular carcinoma from 2006 to 2007 in the Department of Special Needs Treatment, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University. Among them, 35 patients underwent complete hepatectomy with selective hemihepatic flow block (group A), and the remaining 65 patients underwent hepatectomy with total hepatic flow block (group B), comparing the intraoperative hepatic flow block time, intraoperative bleeding volume, blood transfusion volume, hepatic resection volume, postoperative liver function recovery, complication rate and other indexes between the two groups. Results The mean intraoperative bleeding volume and the mean transfusion volume of transfused patients in group A were significantly less than those in group B (P < 0,05). In the case that the duration of hepatic blood flow blockage was significantly longer in group A than in group B (P < 0, 05) and there was no significant difference in the amount of hepatic resection between the two groups, the serum pre-albumin level was significantly higher in group A than in group B at the 3rd and 7th postoperative d (P < 0, 05), while the serum alanine transaminase levels were significantly lower in group A than in group B at the 1st, 3rd and 7th postoperative d (P < 0, 01). The total complication rate during postoperative hospitalization was 34%, and there was no significant difference in the complication rate between the two groups (P > 0, 05). Conclusion Selective hemihepatic flow complete blockade hepatectomy can significantly reduce bleeding during hepatectomy and mitigate liver function damage.
The amount of blood loss during hepatectomy is one of the most important factors affecting the operative mortality and postoperative complication rate. Currently, the commonly used methods of hepatic blood flow blockage have shortcomings such as incomplete blood flow blockage, ischemia-reperfusion injury to the remaining liver tissue, and altered systemic hemodynamics. How can we effectively control blood loss during hepatic resection while avoiding ischemic damage to the remaining liver tissue and stasis of the kidney and gastrointestinal tract, and at the same time prevent the occurrence of air embolism? In this paper, we introduce selective hemihepatic hemipelvectomy under complete blockage of blood flow, and report as follows.
1.Data and methods
1.1 General data: From February 2006 to February 2007, 35 cases (Group A) of regular hepatectomy under selective hemihepatic flow complete blockade without more than half liver were performed in our department for primary hepatocellular carcinoma, including 29 males and 6 females, aged 30-72 years, with a median age of 53 years. The preoperative liver function was all Child-Pugh grade A. The pathological diagnosis was hepatocellular carcinoma in 30 cases and cholangiocarcinoma in 5 cases. The tumor diameters ranged from 2,3 to 15,5 cm, with a mean of (7,04±5,33) cm. 12 cases (34,29%) were combined with post-hepatitis cirrhosis, and 6 cases (17,14%) were combined with portal vein carcinoma embolism. During the same period, 65 cases (group B) underwent regular hepatectomy with no more than half of the liver under whole liver into liver blood flow blockage for primary liver cancer, including 51 men and 14 women, aged 27-68 years, with a median age of 52 years. Preoperative liver function was Child-Pugh grade A in all cases. The pathological diagnosis was hepatocellular carcinoma in 50 cases, bile duct cell carcinoma in 11 cases, and mixed hepatocellular carcinoma in 4 cases. The tumor diameters ranged from 2,5 to 20,5 cm, with a mean of (8,75±6,65) cm. 29 cases (44,62%) were combined with post-hepatitis cirrhosis, and 20 cases (30,77%) were combined with portal vein carcinoma thrombosis. In both groups, the tumors were single, and the surgery was performed by the same surgeon, with additional cholecystectomy in 20 cases in group A and 29 cases in group B. No other additional surgery was performed in either group. There was no statistically significant difference between the two groups in terms of gender composition, liver function classification, tumor diameter, cirrhosis rate, incidence of portal vein carcinoma embolism and pathological type. 10 cases of right hemicolectomy, 7 cases of left hemicolectomy, 2 cases of right upper hemicolectomy, 4 cases of right lower hemicolectomy, 6 cases of right posterior hepatic lobectomy and 6 cases of left outer hepatic lobectomy were performed in group A, while 21, 12, 2 and 5 cases were performed in group B, respectively. The difference between the two groups was not statistically significant (chi-square value = 1,3047, P>0,05).
1, 2 Hepatic blood flow blocking methods: (1) complete hepatic blood flow blocking method: firstly, the gap between the right hepatic vein and the middle hepatic vein was revealed at the second hepatic portal after fully freeing the affected hepatic half, the peritoneum of the anterior wall of the inferior hepatic inferior vena cava was cut, and a long curved vascular clamp was used to blindly separate upward between the anterior wall of the inferior vena cava and the liver tissue along the midline of the anterior wall of the posterior hepatic inferior vena cava until the tip of the vascular clamp passed between the right hepatic vein and the combined trunk of the left and middle hepatic veins The tip of the vascular forceps is passed between the root of the right hepatic vein and the combined left and middle hepatic veins, clamped at the midpoint of a 60 cm long umbilical cord line, pulled downward through this posterior hepatic tunnel, and cut into two at the midpoint. One upper end is wound anteriorly downward from the hepatic diaphragm in the plane of the median hepatic fissure, and the lower end is passed posteriorly and anteriorly from the superior edge of the hepatic portal plate, ready to tighten the upper and lower ends in order to block bleeding from the traffic branch vessels on the healthy side of the hepatic section. The other upper end is wound posterior to the affected hepatic vein and tightened with the other end to block the affected hepatic vein and short hepatic vein. A vascular clamp is placed immediately outside the Glisson sheath at the superior edge of the transverse hepatic sulcus on the affected side and separated posteriorly and inferiorly with the fingers of the left hand guiding behind the hepatic hilum, and the vascular clamp is passed posteriorly through the Glisson sheath with a latex tube for blocking the inflow to the liver on the affected side. The order of blocking was left and right interhepatic traffic branch vessels, the first hepatic portal on the affected side, the hepatic vein on the affected side, and the short hepatic vein; (2) whole hepatic inflow blocking method: the hepatic artery and portal vein were blocked by tying the hepatoduodenal ligament with latex tubes.
1, 3 Statistical methods: SPSS v11, 0 software was selected for statistical analysis. The t-test was used for the measurement data, and the chi-square test was used for the count data.
2, Results
2.1 Intraoperative vital signs were stable in both groups, and invasive arterial pressure monitoring kept systolic pressure above 90 mmHg (1 mm Hg = 0.133 kPa) and oxygen saturation was 100%. no intraoperative hepatic vein air embolism occurred in group A, while 3 cases (4.62%) occurred in group B. Due to the small amount of air embolism and timely detection and treatment by anesthesiologists, no serious consequences were caused. No surgical deaths in either group.
2, 2
Intraoperative hepatic flow block time: 10 to 48 min in group A, mean (31, 47±10, 25) min; 12 to 32 min in group B, mean (24, 70±6, 53) min. intraoperative first hepatic portal block was once in all cases, and intraoperative hepatic flow block time was significantly longer in group A than in group B (t=3, 5398, P<0, 05).
2, 3
Intraoperative bleeding: group A 50-850 mL, mean (320, 00±292, 69) mL, bleeding mainly occurred when the liver was free and dissected vessels, and there was almost no bleeding on the liver trabeculae during liver dissection; group B 100-2300 mL, mean (540, 00±671, 98) mL, bleeding mainly came from the hepatic venous system of the liver dissection. intraoperative bleeding in group A was significantly less than that in group B ( t=2, 2698, P<0, 05). 8 cases (22, 86%) in group A and 20 cases (30, 77%) in group B had intraoperative blood transfusion, with mean transfusion volumes of (925, 00±212, 13) mL and (1340, 00±411, 80) mL, respectively, and the mean transfusion volume in group A was significantly less than that in group B (t=2, 6897, P<0, 05).
2, 4
Liver resection volume (measured according to postoperative pathology): 144 to 2016 cm3 in group A, mean (822, 20±773, 31) cm3; 126 to 2868 cm3 in group B, mean (1125, 80±832, 23) cm3. no statistically significant difference between the two groups (t=1, 7828,P＞0, 05).
2,5
Comparison of postoperative liver function between the two groups is shown in Table 3. serum pre-albumin levels on postoperative days 3 and 7 were significantly higher in group A than in group B (P < 0,05), and serum alanine aminotransferase levels on postoperative days 1, 3 and 7 were significantly lower in group A than in group B (P < 0,01).
2, 6
The total complication rate during the postoperative hospitalization was 34%, and the complication rate in group A was 31, 43% (11/35), while that in group B was 35, 38% (23/65). Postoperatively, 8 cases of pleural fluid (22, 86%), 5 cases of ascites (14, 29%) and 2 cases of bile leak (5, 71%) required puncture treatment in group A. In group B, 14 cases of pleural fluid (21, 53%), 10 cases of ascites (15, 38%) and 8 cases of bile leak (12, 31%) required puncture treatment. With the recovery of liver function and treatment with diuresis and punctal fluid extraction, both chest and ascites subsided. 1 case in group A and 4 cases of bile leak in group B were cured spontaneously by abdominal drainage, and the rest of bile leaks were cured by ERC+ERBD treatment. There was no statistically significant difference in the incidence of the above complications between the two groups (P>0,05).
3. Discussion
In addition to the surgical operation in hepatectomy, the hepatic blood flow blocking method to control bleeding during hepatic dissection plays a crucial role in the success of the operation, the patient’s postoperative recovery and the satisfactory long-term outcome. Several aspects need to be taken into account when performing hepatic blood flow blockade in primary liver cancer surgery.
1.Reducing bleeding and blood transfusion
Heavy bleeding during hepatectomy is one of the most important factors affecting postoperative mortality and complication rate. Inadequate perfusion of systemic organs caused by intraoperative hemorrhage can result in severe organ dysfunction or even failure. Patients with intraoperative hemorrhage have significantly increased liver function damage, the duration of damage is significantly longer, and the incidence of complications such as postoperative liver failure and surgical death is significantly higher. Huang Gengwen et al. reviewed 177 cases of large hepatocellular carcinoma resection, suggesting that the amount of intraoperative bleeding and blood transfusion were positively correlated with the incidence of postoperative complications, and the amount of blood transfusion was one of the independent risk factors determining the occurrence of postoperative complications after large hepatocellular carcinoma resection. Meanwhile, there is evidence that immunosuppression associated with perioperative blood transfusion has a negative impact on the prognosis of patients undergoing radical tumor surgery. Allogeneic blood transfusion brings a large number of foreign antigens into the body, and the persistence of these antigens in the circulation may cause immune dysregulation, manifested as immunosuppression, response incompetence and clonal elimination, promoting tumor recurrence and metastasis. Such as patients with large amount of blood transfusion is also prone to adverse reactions and complications such as coagulation dysfunction, electrolyte disorders, hemodilution and metabolic acidosis. Therefore, in order to reduce intraoperative bleeding and transfusion, various hepatic blood flow blocking methods have been widely and maturely applied in clinical practice, such as Pringle method, hemihepatic blood flow blocking method, total hepatic blood flow blocking method, selective total hepatic blood flow blocking method and so on. These hepatic flow blocking methods effectively control intraoperative blood loss and transfusion volume, reducing the incidence of surgical death and postoperative complications.
2.Protection of residual liver function
Rapid recovery of liver function after surgery is essential to evaluate the success of surgery. However, blocking liver blood flow in order to reduce bleeding during hepatotomy will inevitably cause ischemia and reperfusion of liver tissues, damaging the liver’s ability to proliferate and repair, and even leading to liver failure. The most direct and effective way to protect the remaining liver function is to avoid ischemia-reperfusion injury to the remaining liver. Selective hepatic flow blockade only blocks blood flow to the affected side of the liver, which does not cause ischemia-reperfusion injury to the remaining liver, and the postoperative liver function index is significantly better than that of the Pringle method. Since the blood flow of the unblocked side of the liver is not affected, it will not cause significant ischemia-reperfusion damage to the remaining liver, so the duration of selective hepatic flow blockade is not strictly limited, which makes hepatic resection more comfortable.
3.Avoid air embolism in the hepatic reflux venous system
The hepatic vein is a reflux vessel and close to the right atrium, which is normally under negative pressure. When removing the tumor which is close to the main trunk of the hepatic vein or the root of the hepatic vein, it will inevitably damage the thin hepatic vein wall, so in addition to hemorrhage, it is more dangerous that a large amount of air enters the atrium and pulmonary artery through the fissure of the hepatic vein wall to cause fatal embolism. Nowadays, selective hepatic flow blockade has solved this problem very well. In a controlled study of hepatic tumor resection close to the hepatic vein trunk, one author performed Pringle block in 110 cases and selective hepatic flow block in 125 cases (blocking the incoming hepatic blood flow while blocking the associated hepatic vein trunk), and as a result, 14 cases of major bleeding and 3 cases of air embolism occurred in Pringle block, while no major bleeding or air embolism occurred in selective hepatic flow block.
4.Low impact on other organs and hemodynamics
When hepatic resection completely blocks the blood flow into the hepatic portal vein, the gastrointestinal venous blood flow is blocked, resulting in gastrointestinal stasis and edema of the gastrointestinal wall, which impairs the barrier function of the mucosa and can lead to bacteremia and endotoxemia and aggravate liver and intestinal injury. If total hepatic blood flow is blocked, the amount of cardiac blood return is drastically reduced, the blood pressure and heart rate are obviously changed, and the organs above the diaphragm are prone to ischemia while the organs below the diaphragm are stasis, which can cause different degrees of damage to each organ and even lead to serious postoperative complications. Therefore, the above-mentioned blood flow blockage time should be minimized during hepatectomy, and preferably such blood flow blockage should be avoided. At present, the widely used selective hepatic hemiflow blockade is a more advantageous method of hepatic hemiflow blockade because it can effectively control intraoperative blood loss while not completely blocking portal venous blood flow and keeping the inferior vena cava unobstructed, thus avoiding the occurrence of the above adverse events.
5.Preventing tumor metastasis inside and outside the liver of medical origin
Primary hepatocellular carcinoma most commonly spreads and metastasizes through the portal vein to form cancer nodules in the liver, and cancer cells also metastasize distantly through the hepatic vein to the lung, adrenal gland, bone, kidney and brain. Intraoperative freeing of the liver and compression of the tumor are more likely to induce medical metastasis through the above pathways. The selective hemihepatic flow blocking method blocks the unilateral portal vein and hepatic vein, avoiding tumor cells from spreading metastasis through these pathways during surgery, but there are still traffic branches in the left and right portal vein, which is one of the ways for hepatocellular carcinoma to develop contralateral metastasis, and more perfect methods are needed to solve this problem.
6.The operation is relatively simple and easy to perform
The simplest and most practical method to block the blood flow into the liver is Pringle method, which has almost no operation risk and exact effect of reducing intraoperative bleeding. Selective hemihepatic flow blocking method requires dissection of one side of the hepatic hilar, and also requires extrahepatic separation of the hepatic vein or direct instrumentation to block the hepatic vein, which is more time-consuming, and there is a greater risk of separating the hepatic vein outside the liver. The most complete total hepatic flow blocking method for controlling bleeding requires prepositioning of blocking bands in the subhepatic and infrahepatic vena cava, which is difficult because the subdiaphragmatic segment of the infrahepatic vena cava is very short and has little space for freeing.
Therefore, it is of great clinical significance to explore a method to completely block the affected liver blood flow that has the advantages and avoids the shortcomings of all existing hepatic flow blocking methods to reduce intraoperative bleeding, reduce postoperative complications, avoid medical dissemination of tumor, and improve survival rates.
In 2001, Belghiti J et al. proposed a safe method of right hemihepatectomy without freeing the liver – the suspension method. In this method, a band is placed between the anterior wall of the inferior vena cava and the liver along the longitudinal axis of the inferior vena cava, and the band is lifted during liver resection to separate the liver from the anterior wall of the inferior vena cava and maintain tension, which makes it easier to reveal and handle the short hepatic vein, and it is not advisable to damage the inferior vena cava (the sling creates a gap between the inferior vena cava and the liver) when the liver is resected, and the hepatic parenchyma on the resection surface is compressed and hemostatic by the tension of the upward lifting of the sling. The effect is to stop the bleeding. However, this method still requires blocking the first hepatic portal and has the advantages and shortcomings of whole liver into liver blood flow blockage. It gives us the insight that there is an avascular gap between the anterior wall of the inferior vena cava and the liver and that placement of the band within this gap is feasible and that local compression of the parenchyma of the hepatic section by the sling can further reduce bleeding in the hepatic section.
In 2006, B Trotovsek et al. performed an anatomical study in order to evaluate the safety of liver resection by the suspension method and observed 100 cadaveric liver specimens and found a 4-6 cm long avascular zone between the anterior wall of the inferior vena cava and the liver, with a width of 2-15 mm at the narrowest point and a mean of (8,7±2,3) The results of the study suggest that it is safe and feasible to place a band in the avascular zone between the inferior vena cava and the liver, and Gaujoux S et al. applied the suspension method to clinical hepatectomy with a success rate of more than 95%, further demonstrating that the method is safe and feasible.
In China, Pang Shuji et al. improved on Belghiti’s suspension method by performing an anterior approach to hepatectomy with a liver-wrapping lift and applied the posterior hepatic tunnel and liver-wrapping band to various difficult hepatectomies. This method replaces hilar block and total hepatic flow block with a band around the liver to avoid hepatic ischemia-reperfusion injury, gastrointestinal stasis and hemodynamic effects, but it does not prevent hepatic vein bleeding, air embolism and tumor metastasis through the hepatic vein because the hepatic vein is not blocked.
In order to retain the advantages and avoid the shortcomings of various current hepatic flow blocking methods, this study was designed on the basis of the above anatomical and clinical studies for selective hepatic resection under complete hepatic flow blocking, and was initially applied to 35 cases of regular hepatectomy with no more than half liver. The results showed that intraoperative bleeding was significantly less than that in the group with total hepatic inflow blockade, and there was basically no bleeding on the hepatic wound during hepatectomy, indicating that the method could more thoroughly control bleeding during hepatectomy. intraoperative blood transfusion in group A was also correspondingly less than that in group B, and the ideal control of bleeding and blood transfusion was conducive to reducing the occurrence of postoperative complications. The method ensured that the blood supply to the healthy hemihepatic was not affected. In the case that the blocking time was longer in group A than in group B and there was no significant difference in the volume of hepatectomy, the serum pre-albumin levels on postoperative day 3 and 7 in group A were significantly higher than in group B, indicating that the postoperative hepatic synthetic function was significantly better in group A than in group B. The comparison of serum glutamate transaminase levels on postoperative day 1, 3 and 7 illustrated that the hepatocyte damage in group B was more obvious than in group A, and the selective In group A, intraoperative air embolism was avoided because the hepatic vein and short hepatic vein were blocked, while in group B, only the first hepatic portal was blocked, and intraoperative air embolism occurred in 3 cases, which could directly lead to death if serious air embolism occurred.
The key step of this procedure is the establishment of the posthepatic tunnel, if the posthepatic tunnel is not successfully established, the selective hemihepatic flow cannot be completely blocked. 35 cases in group A all successfully established the posthepatic tunnel, when blindly separating the anterior wall of the posthepatic inferior vena cava, we should pay attention to keep the vascular clamp on the midline and carefully appreciate the resistance of the head end of the vascular clamp, otherwise it is very easy to cause rupture and bleeding of the short hepatic vein. Otherwise, the short hepatic vein may rupture and bleed. In case of greater resistance to vascular forceps, the procedure should be abandoned or intraoperative ultrasound should be used to determine whether there is a short hepatic vein passing through the anterior wall of the inferior vena cava to determine the feasibility of post-hepatic tunneling. If bleeding from the short hepatic vein is inadvertently caused during the establishment of the post-hepatic tunnel, the tunnel can be filled with gelatin sponge to play the role of compression to stop the bleeding, as the short hepatic vein is a reflux vessel often under negative pressure, the bleeding can generally be controlled.
Selective hemihepatic flow blocking method has the following advantages: (1) no bleeding on the wound surface when cutting the liver; (2) the blood supply of the healthy hepatic half can be ensured and the liver function is lightly damaged; (3) the blocking time does not need to be strictly controlled and the operation can be carried out comfortably; (4) the first, second and third hepatic hilum do not need to be dissected, which simplifies the operation steps; (5) the gastrointestinal tract is free of stasis and the mucosal barrier function is not damaged, which can avoid bacteremia and endotoxemia; (6) the endotoxemia can be avoided. (6) The blockage of hepatic vein, short hepatic vein and intrahepatic traffic branch vessels not only avoids the occurrence of air embolism, but also reduces the chance of tumor metastasis within and outside the liver of medical origin; (7) The circulatory system is stable and has little influence on the function of other organs. As long as the liver tumor does not affect the placement of the blocking band, this surgical method can be performed. This method is suitable for resection of hepatic tumors located in the hemihepatic, with clearance from the first and second hepatic hilum and not yet compressing the inferior vena cava. This method is safer than other methods for hepatic resection with cirrhotic base. The results of this study validate most of the above advantages, but it remains to be observed in long-term follow-up whether this method can actually reduce the chance of tumor metastasis of medical origin within and outside the liver.
Selective hemihemispheric complete hepatic flow block hepatectomy combines the advantages and overcomes the shortcomings of the current major hepatic flow block methods and is worthy of promotion. With the gradual maturation of this method and long-term follow-up of more cases, its advantages will become more and more obvious in clinical application.