BACKGROUND: Postoperative liver failure consequent to insufficiency of remnant liver is a feared complication in patients who underwent extensive liver resections. To induce rapid and significant hepatic hypertrophy, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been recently developed for patients which tumor is previously considered unresectable. AIM: To present the Brazilian experience with ALPPS approach. METHOD: Were analyzed 39 patients who underwent hepatic resection using ALPPS in nine hospitals. The procedure was performed in two steps. The first operation was portal vein ligation and in situ splitting. In the second operation the right hepatic artery, right bile duct and the right hepatic vein were isolated and ligated. The extended right lobe was removed. There were 22 male (56.4%) and 17 female (43.6%). At the time of the first operation, the median age was 57.3 years (range: 20-83 years). RESULTS: The most common indication was liver metastasis in 32 patients (82.0%), followed by cholangiocarcinoma in three (7.7%). Two patients died (5.2%) during this period and did not undergo the second operation. The mean interval between the first and the second operation was 14.1 days (range: 5-30 days). The volume of the left lateral segment of the liver increased 83% (range 47-211.9%). Significant morbidity after ALPPS was seen in 23 patients (59.0%). The mortality rate was 12.8% (five patients). CONCLUSION: The ALPPS approach can enable resection in patients with lesions previously considered unresectable. It induces rapid liver hypertrophy avoiding liver failure in most patients. However still has high morbidity and mortality.
BACKGROUND: The success of a transplant depends mainly on the viability of the graft, which is currently the main point of difficulty focuses on the triad preservation-rejection-infection. There are several specific components of preservation solutions that could prevent certain tissue damage. From these components, the osmotic factor has been highlighted as a factor in preventing edema and subsequent cell death, suggesting a possible advantage in the use of hypertonic solutions for organ preservation. AIM: To compare different hypertonic solutions as alternative to liver preservation. METHOD: A total of 105 Wistar rats were divided in Standard Group (GP, n=5 rats), to verify the normal range of the study, and five experimental groups of 20 rats each, according to the preservation solution used: Group Eurocollins (GE), Group Saline 0.9% (GF), Group Glucose 50% (GG), Group Mannitol 20% (GM), Group Salty - NaCl 7.5% (GS). All animals in experimental group were also divided into four subgroups according to the time of collection in: 0 h, 2 h, 6 h and 12 h. Was assessed cell viability by the reaction with Methyl Blue Thiazolyl (MTT) and the dosages of lactate and alanine aminotransferase (ALT). RESULTS: Regarding the lactate level, was observed a relative improvement of hypertonic solutions compared to eurocollins, and in 12 h, the GE and GS showed no statistically significant difference (p> 0.05). When assessed cell viability, absorbance at MTT also demonstrated favorable results to the GS, since no statistically significant difference in relation to GE. CONCLUSION: The 7.5% NaCl solution showed promising results for organ preservation, presenting parameters and capability comparable to eurocollins preservation solution.
Partial portal vein ligation causes an increase in portal pressure that remains stable even after the appearance of collateral circulation, with functional adaptation to prolonged decrease in portal blood flow.
To assess whether different constriction rates produced by partial ligation of the vein interfere with the results of this experimental model in rats.
Three groups of five rats each were used; in group 1 (sham-operated), dissection and measurement of portal vein diameters were performed. Portal hypertension was induced by partial portal vein ligation, reducing its size to 0.9 mm in the remaining 10 animals, regardless of the initial diameter of the veins. Five animals with portal hypertension (group 2) underwent reoperation after 15 days and the rats in group 3 after 30 days. The calculation of the constriction rate was performed using a specific mathematical formula (1 - π r 2 / π R2) x 100% and the statistical analysis with the Student t test.
The initial diameter of the animal's portal vein was 2.06 mm, with an average constriction rate of the 55.88%; although the diameter of the veins and the constriction rate in group 2 were lower than in group 3 (2.06 mm - 55,25% and 2.08 mm - 56.51%, respectively), portal hypertension was induced in all rats and no significant macroscopic differences were found between the animals that were reoperated after 15 days and after 30 days respectively, being the shorter period considered enough for the evaluation. Comparing the initial diameter of the vein and the rate of constriction performed in groups 2 and 3, no statistic significance was found (p>0.05).
Pre-hepatic portal hypertension in rat can be induced by the reduction of the portal vein diameter to 0.9 mm, regardless the initial diameter of the vein and the vessel constriction rate.
Hepatosplenic schistosomiasis is an endemic disease prevalent in tropical countries and is associated with a high incidence of portal vein thrombosis. Inflammatory changes caused by both parasitic infection and portal thrombosis can lead to the development of chronic liver disease with potential carcinogenesis.
To assess the incidence of portal vein thrombosis and hepatocellular carcinoma in patients with schistosomiasis during long-term follow-up.
A retrospective study was conducted involving patients with schistosomiasis followed up at our institution between 1990 and 2021.
A total of 126 patients with schistosomiasis were evaluated in the study. The mean follow-up time was 16 years (range 5–31). Of the total, 73 (57.9%) patients presented portal vein thrombosis during follow-up. Six (8.1%) of them were diagnosed with hepatocellular carcinoma, all with portal vein thrombosis diagnosed more than ten years before.
The incidence of hepatocellular carcinoma in patients with schistosomiasis and chronic portal vein thrombosis highlights the importance of a systematic long-term follow-up in this group of patients.
The negative result of a research does not always indicate failure, and when the data do not permit a proper conclusion, or are contrary to the initial project, should not simply be discarded and archived.
To report failure after performing experimental model of liver ischemia and reperfusion normothermic, continuous or intermittent, in small animals aiming at the study of biochemical and histological parameters after postoperative recovery.
Fifteen Wistar rats were divided into three groups of five animals each; all underwent surgery, the abdomen was sutured after the proposed procedures for each group and the animals were observed for 6 h or until they died, and then were reoperated. In Group 1, control (sham-operated): dissection of the hepatic hilum was performed; in Group 2: clamping of the hepatic hilum for 30 m; in Group 3: clamping of the hepatic hilum for 15 m, reperfusion for 5 m and another 15 m of clamping. Data from Groups 2 and 3 were compared with Student's t test.
All animals of Group 1 survived for 6 h. Two animals in Group 2 died before the 6 h needed to validate the experiment; two did not recover from anesthesia and one survived until the end. In Group 3, four animals died before the 6 h established and one of them survived the required time. Only one animal in Group 2 and one in Group 3 survived and were able to accomplish the study. There was no statistical significance when the results of Groups 2 and 3 were compared (p>0.05).
The death of six animals before the necessary period of observation turned the initial proposal of the experiment unfeasible.
Pancreatoduodenectomy after neoadjuvant chemotherapy is the current treatment in patients with borderline pancreatic ductal adenocarcinoma in the head of the pancreas1,2,3. The total mesopancreas excision concept includes the resection of the lymphatic structures on the right side of the SMA and along the neuronal plexus of the pancreatic head. Complete clearance of this retroperitoneal area may increase the R0 resection rate in patients with adenocarcinoma in the head of the pancreas. This area is an important location of perineural infiltration of tumor cells in patients with pancreatic ductal adenocarcinoma4.
Hackert et al5 described the term “triangle operation” as a new surgical technique for patients with locally advanced pancreatic ductal adenocarcinoma and stable disease following neoadjuvant therapy. This area is defined by SMV/PV, celiac axis/common hepatic artery, and SMA, representing the typical view after completion of the resection. However, according to the definition of the authors, the procedure should be performed without arterial resection. Recently, Loss et al6 and Schneider et al7 observed that arterial resection is effective in patients with locally advanced pancreatic cancer after neoadjuvant chemotherapy, with better long-term survival than with palliative treatment. However, this procedure should be performed in experienced pancreatic centers. After neoadjuvant chemotherapy and centers with expertise in pancreatic resection, arterial resection is perfectly possible with acceptable morbidity and mortality.
Knowledge of the portal system and its anatomical variations aids to prevent surgical adverse events. The portal vein is usually made by the confluence of the superior mesenteric and splenic veins, together with their main tributaries, the inferior mesenteric, left gastric, and pancreaticoduodenal veins; however, anatomical variations are frequent.
This article presents a literature review regarding previously described anatomical variations of the portal venous system and their frequency.
A systematic review of primary studies was performed in the databases PubMed, SciELO, BIREME, LILACS, Embase, ScienceDirect, and Scopus. Databases were searched for the following key terms: Anatomy, Portal vein, Mesenteric vein, Formation, Variation, Variant anatomic, Splenomesenteric vein, Splenic vein tributaries, and Confluence.
We identified 12 variants of the portal venous bed, representing different unions of the splenic vein, superior mesenteric vein, and inferior mesenteric vein. Thomson classification of the end of 19th century refers to the three most frequent variants, with type I as predominant (M=47%), followed by type III (M=27.8%) and type II (M=18.6%).
Thomson classification of variants is the most well-known, accounting for over 90% of portal venous variant found in clinical practice, inasmuch as the sum of the three junctions are found in over 93% of the patients. Even though rarer and accounting for less than 7% of variants, the other nine reported variations will occasionally be found during many abdominal operations.
The role of autonomic nervous system in the development and maintenance of portal hypertension is not fully elucidated. It is known that the gene expression of norepinephrine in the superior mesenteric artery varies with time, and it may contribute for splanchnic vasodilation and its consequent hemodynamic repercussions. It is still not known exactly how the adrenergic expression behaves at the heart level in the initial stages of this process.
To evaluate the immunohistochemical expression of the enzyme tyrosine hydroxylase (tyrosine 3-monooxygenase), involved in the synthesis of norepinephrine, in the myocardium of rats submitted to partial ligation of the portal vein.
Twenty-four Wistar rats were divided into two groups: Sham Operated and Portal Hypertension. The partial ligation was performed in the Portal Hypertension group, and after 1/6/24 h and 3/5/14 days the animals were euthanized. Immunohistochemical analysis was performed to quantify the expression of the stained enzyme using the ImageJ program.
The Portal Hypertension group expressed percentages between 4.6-6% of the marked area, while the Sham Operated group varied between 4-5%. Although there was no statistical significance, the percentage stained in the Portal Hypertension group followed an increasing pattern in the first 6 h and a decreasing pattern after 24 h, which was not observed in the Sham Operated group.
The expression of noradrenaline in rat myocardium during the first two weeks after partial ligation of the portal vein, with tyrosine hydroxylase as marker, did not show differences between groups over time.
When a major hepatic resection is necessary, sometimes the future liver remnant is not enough to maintain sufficient liver function and patients are more likely to develop liver failure after surgery.
To test the hypothesis that performing a percutaneous radiofrecuency liver partition plus percutaneous portal vein embolization (PRALPPS) for stage hepatectomy in pigs is feasible.
Four pigs (Sus scrofa domesticus) both sexes with weights between 25 to 35 kg underwent percutaneous portal vein embolization with coils of the left portal vein. By contrasted CT, the difference between the liver parenchyma corresponding to the embolized zone and the normal one was identified. Immediately, using the fusion of images between ultrasound and CT as a guide, radiofrequency needles were placed percutaneouslyand then ablated until the liver partition was complete. Finally, hepatectomy was completed with a laparoscopic approach.
All animals have survived the procedures, with no reported complications. The successful portal embolization process was confirmed both by portography and CT. In the macroscopic analysis of the pieces, the depth of the ablation was analyzed. The hepatic hilum was respected. On the other hand, the correct position of the embolization material on the left portal vein could be also observed.
“Percutaneous radiofrequency assisted liver partition with portal vein embolization” (PRALLPS) is a feasible procedure.
HEADINGS:
Embolization, Hepatectomy, Radiofrequency, Portal vein,
Desenvolvido por Surya MKT