The most life-threatening complication during liver resections is hemorrhage whether intraoperative or post-operative . Unlike adults, children have small blood volumes and can suffer greatly from blood loss as small as 100 ml. Furthermore, children have near-normal liver tissue leading to more hemorrhage when compared to cirrhotic adult liver . Meticulous surgical techniques are crucial to minimize blood loss, particularly avoiding injury to the small tributaries draining into the inferior vena cava which should be ligated in continuity then cut, instead of cauterized, because they will bleed extensively if severed . Wang and his colleagues suggested that maintaining a low central venous pressure (2–4 mmHg) can reduce blood loss . In our cases, we were keen to maintain central venous pressure below 5 cmH2O to decrease bleeding and blood transfusion. If injury to one of the hepatic veins has occurred, the anesthesiologist deliberately increased the peak end expiratory pressure to guard against air embolism. The Society of Pediatric Oncology Liver Tumor Study Group launched its first prospective trial (SIOPEL-1) in 2002. Among the 100 patients who underwent hepatectomy, hemorrhage was less than 500 ml in 60% of cases, while it was more than 1000 ml in 13% of them . In comparison, intraoperative blood loss was less than 500 ml in all our cases. In a study published in 2017 , Busweiler and his colleagues reported blood transfusion in 45% of 73 patients underwent partial hepatectomy. In our series, 18.5% of our patients received blood transfusion.
Many vascular clamping techniques are available in the surgeon’s hands. Pringle’s maneuver being the simplest and highly effective. However, ischemia of remaining liver and intestinal congestion always occur. Total vascular exclusion ensures a bloodless operation, but still has its drawbacks on hemodynamic stability. Makuuchi and his coworkers described selective vascular exclusion in 1987 obviating disadvantages of both Pringle’s maneuver and total vascular exclusion . Selective vascular occlusion together with high dissection of the porta hepatis and ligation of up to second-order branches of portal and arterial vessels were used in our series. This technique has been proved to be both effective and safe by many other authors . It decreases visceral congestion as part of the portal flow is preserved, furthermore only the excised portion of the liver is subjected to anoxia .
Many methods are available for parenchymal resection such as finger fracture, clamp crushing, and different energy devices [13,14,15]. Among the variety of parenchymal resection methods enumerated, we opted for the use of harmonic scalpel. Harmonic scalpel causes protein denaturation and coagulation by high-frequency ultrasound vibration. Despite decreasing resection time and bleeding when compared to finger fracture, it was associated with a higher incidence of the biliary leak . We did have 5 cases (18.5%) with postoperative minor biliary leak in our series; however, all were treated conservatively.
Intraoperative ultrasonography was introduced in the 1980s . Since then, intraoperative ultrasonography has been a very useful tool to define the extent of the mass and its relation to the important vascular structures. It can detect new tumors not diagnosed preoperatively or reveal new information about the lesion . Several reports suggested a rate of 20% alteration in surgical plan due to information gained from intraoperative ultrasonography . In our series, it changed our initial plan from right posterior hepatectomy to right hepatectomy in 2 cases (7.4%) due to the detected change in tumor extent. Also, delineation of the main hepatic veins was of great help to decrease blood loss.
Biliary leak is not an uncommon complication after hepatectomies. Most are minor leaks from the resection margin, which resolve with expectant management. However, rare leaks from disconnected ducts or excluded segment duct may carry a grave prognosis . Such major leaks are commonly caused by aberrant anatomy of biliary tree. Trans-cystic cholangiography using radio-opaque dye, methylene blue, indigo-carmine, fat emulsion, or normal saline is recommended by many authors to diagnose and suture any leak [21, 22]. We did not use any bile leakage test initially in the first 15 cases. We had a minor biliary leak in 4 cases (26.7%). Therefore, we started to use saline test routinely. As a result, we had only 1 case of minor bile leak in our subsequent 12 cases. Yamashita and his coauthors reported incidence of 4.5% bile leak without leak test and 0% after they started testing with saline . They concluded that saline test is safe and effective in reducing bile leak rates to 0%.
A case with HCC and hepatitis C virus died due to hepatic insufficiency after extended right hepatectomy, although CT volumetry of this patient confirmed adequacy of remnant liver tissue. Inaccuracy in CT volumetry results may be attributed to the difference between radiological plane and actual surgical plane. Radtke and associates reported overestimation of volume in 61% of cases and underestimation in 15% due to extreme difficulty to follow Cantlie’s line especially in two-dimensional images . Furthermore, CT volumetry does not assess for the function in the remnant liver tissue; therefore, it is only accurate in patient with healthy parenchyma. Dinant and others reported 13% liver cell failure despite adequate remnant liver tissue calculated by volumetry. They concluded that hepatobiliary scintigraphy is more accurate in assessing adequacy of future remnant . Also, the use of a fixed conversion factor when converting volume to weight is doubtful since there may be individual variation .
Although hepatic venous outflow obstruction due to torsion is a well-known life-threatening complication after liver transplantation, it has been reported sporadically in the literature in the remaining left lobe after right hepatectomy . To the best of our knowledge, our case is the first to be reported in an infant. This case was early in our series. After which, we have started to routinely fix the remnant liver to the falciform ligament.
Despite advances in surgical techniques, liver resection remains a complex and high-risk procedure. There is limited data in the literature regarding perioperative and short-term outcome in pediatric population. The first prospective trial of The Society of Pediatric Oncology Liver Tumor Study Group (SIOPEL-1) reported 18% surgical morbidity and 5% surgical mortality . In an attempt to define the short-term outcome in children, Zwintscher and his coauthors reviewed the database of 126 children who underwent liver resection in 2009 due to primary hepatic malignancy. They reported 30.7% morbidity and 3.7% mortality . In 2016, a chart review was carried out to assess postoperative complications in children underwent partial hepatectomy for hepatoblastoma in the Netherlands between 1990 and 2013 . Complications were found in 58% of 73 patients but there was no early mortality (within 30 days). In our series, there was an overall morbidity rate of 44.4%, while the mortality rate was 7.4%.
We had an 11.1% infection rate in the form of SSI, but there was no wound dehiscence or reoperation. Vascular complications occurred in 3.6% of our cases in the form of hepatic venous outflow obstruction in one case. In comparison, Busweiler and his colleagues reported 8% infection rate with reoperation on two occasions. Also, they reported vascular complications in 3% of their cases in the form of Budd Chiari Syndrome in one patient and thrombosis of the portal and left hepatic veins in another case .
In adults, minimally invasive liver resection (MILR) is well established for resection of both benign and malignant tumors with comparable outcome to open resection [29, 30]. Different techniques used included pure laparoscopy, hand-assisted laparoscopy, and the hybrid technique . In children, literature and evidence are lacking to support MILR as most published articles are case reports and small case series [31, 32], which can be explained by the rarity of cases and the limited peritoneal domain in children that hinders MILR. To the best of our knowledge, there is only one large retrospective study in the English literature published in 2016, which lacks comparison versus open technique . We believe MILR in pediatric population requires specialized training to develop appropriate expertise, highly equipped theaters, and proper patient selection.
Limitations of our study included being a retrospective one, besides the absence of a control group.