Application of the En Bloc Concept Combined with Anatomic Resection in Laparoscopic Hepatectomy

Summary

Numerous studies have demonstrated the advantages of anatomic resection. Nonetheless, whether anatomic resection can increase R0 resection rates remains controversial. Consequently, the present study describes an innovative procedure involving the en bloc concept combined with anatomic resection in laparoscopic hepatectomy, which can reduce postoperative recurrence and metastasis.

Abstract

Laparoscopic hepatectomy has been reported in many studies, and it is the mainstream method of liver resection. In some particular cases, such as when there are tumors adjacent to the cystic bed, surgeons cannot palpate the surgical margins through the laparoscopic approach, which leads to uncertainty about R0 resection. Conventionally, the gallbladder is resected first, and the hepatic lobes or segments are resected second. However, tumor tissues can be disseminated in the above cases. To address this issue, based on the recognition of the porta hepatis and intrahepatic anatomy, we propose a unique approach to hepatectomy combined with gallbladder resection by en bloc anatomic resection in situ. Firstly, after dissecting the cystic duct, without cutting the gallbladder primarily, the porta hepatis is pre-occluded by the single lumen ureter; secondly, the left hepatic pedicle is made free by the gap of the Laennec membrane and Hilar plate; thirdly, the assistant is asked to drag the fundus of the gallbladder, and the liver parenchyma tissue is resected using a harmonic scalpel along the ischemia line on the liver surface and intraoperative ultrasound. The whole middle hepatic vein (MHV) and its tributaries appear completely; lastly, the left hepatic vein (LHV) is disconnected, and the specimen is taken out from the abdominal cavity. The tumor, gallbladder, and other surrounding tissues are resected en bloc, which meets the tumor-free criterion, and a wide incisal margin and R0 resection are achieved. Therefore, the laparoscopic hepatectomy with the combination of the en bloc concept and anatomic resection is a safe, effective, and radical method with low postoperative recurrence and metastasis.

Introduction

Hepatocellular carcinoma is a common cancer; it is the sixth most common neoplasm in adults and the third leading cause of cancer death worldwide, and its incidence is predicted to rise in the future¹. Surgical resection, ablative electrochemical therapy, transarterial chemoembolization, systemic therapy such as sorafenib, and transplantation have been reported to be effective treatment modalities for liver cancer^2,3. Of these options, surgical resection of hepatocellular carcinoma (HCC) is considered the primary curative treatment since the tumor can be completely removed rather than limited⁴.

Laparoscopic surgery, a minimally invasive technique with fewer perioperative complications compared to open resection⁵, has made great progress worldwide and has steadily become an important surgical method for liver surgery^6,7,8. However, in laparoscopic liver resection, the surgeon's inability to recognize the tumor margins under direct vision and the fear of not being able to ensure laparoscopic hemostasis have discouraged most liver surgeons from attempting this demanding procedure. In 1960, Lin et al. reported a case of right hepatic lobectomy with intrahepatic portal vein pedicle ligation⁹. In 1986, Takasaki also described Glisson's pedicle transect hepatectomy, named extrathecal dissection¹⁰. In 1991, Reich et al. applied laparoscopic resection of benign liver tumors and completed the world's first laparoscopic hepatectomy¹¹. Since then, anatomical hepatectomy has gradually entered the public view while providing technical support for laparoscopic hepatectomy. However, in the case in the present study, the lower end of the tumor reached the cystic plate, and simple traditional anatomic resection could not guarantee an R0 resection, but the management of such cases has rarely been reported in detail. In 1999, Neuhaus et al. proposed the principle of total portal vein resection, which proved to be a good prognostic indicator, increasing the chance of R0 resection¹². Accordingly, with a new understanding of liver anatomy, we advanced a new approach called "en bloc concept combined with anatomic resection", which is depicted in this video protocol.

In this study, the patient was a 67-year-old female admitted to our hospital in August 2021 with mild upper abdominal pain for 1 month. Her medical history was notable for hypertension and diabetes. Abdominal contrast-enhanced computed tomography revealed a mass with heterogeneous enhancement located at segment 4 of the liver, with a size of 247 mm x 54 mm x 50 mm. The lower end of the mass had reached the cystic plate, and the possibility of gallbladder invasion could not be ruled out (Figure 1). The Child-Pugh liver function¹³ was grade A, and the ICG clearance rate^14,15 R15 was 5.1% (<10%). The patient was classified as stage A according to the BCLC algorithm¹⁶ and stage IB according to the CNLC algorithm¹⁷. After a multidisciplinary meeting, it was decided that her treatment should be laparoscopic left lobe resection of the liver and cholecystectomy. The concept of en bloc resection combined with anatomic hepatic resection in laparoscopy was adopted to eliminate the enormous liver mass totally.

Protocol

The procedure was reviewed and approved by the Clinical Research and Application Ethics Committee of the Second Affiliated Hospital of Guangzhou Medical University. The content and methods of the research are in line with medical ethics norms and requirements. The patient was informed of the purpose, background, process, risks, and benefits of the study prior to surgery. The patient understood that participation in this study was voluntary and signed informed consent.

1. Patient positioning, instruments, and port placement

1. Place the patient in the supine and 30° reverse Trendelenburg position on the operating table, and subsequently tilt 30° to the right during the procedure, with the surgeon performing from the right side.
2. Use the five-port technique during the procedure, with three 10 mm trocars, one 5 mm trocar, and one 12 mm trocar for retraction and specimen retrieval. Then, assemble the following hemostatic devices: 30° laparoscope, laparoscopic ultrasonography device, and basic laparoscopic instruments, including a single lumen catheter, a harmonic scalpel, a monopole electrocoagulator, a vascular clip, and a powered endoscopic cutter stapler (see Table of Materials).
3. Administer the patient a combination of intravenous and inhalation anesthesia by giving propofol 150 mg, sufentanil 15 ug, and rocuronium bromide 50 mg intravenously, followed by endotracheal intubation 7.5 F after 90 s.
   NOTE: The selection of the anesthetic agents and the application of intravenous and inhalation anesthesia are decided and performed by the anesthetist on a case-to-case basis.
   1. During the parenchymal transection, lower the central venous pressure by 3-5 cm H₂O to reduce hepatic venous bleeding while limiting the fluid replacement as much as possible. Place a lumen catheter and nasogastric tube (see Table of Materials) in the bladder and stomach for urinary volume recording and decompression.
4. Routinely place a preoperative arterial line and a central venous (internal jugular vein) catheter. Use a 10 mm trocar for the observation port 2 cm below the umbilicus. Then, establish pneumoperitoneum by insufflating carbon dioxide, and maintain the intra-abdominal pressure at 12-14 mmHg (1 mmHg, 1/4 0.133 kPa).
5. Place the other four trocars in the following locations: the 5 mm trocar in the right anterior axillary line, the 12 mm trocar in the right midclavicular line under the costal margin, the 10 mm trocar in the left anterior axillary line, and the 10 mm trocar in the left midclavicular line under the costal margin (Figure 2).

2. Surgical technique

1. Pull the fundus of the gallbladder upward, and use a harmonic scalpel (see Table of Materials) for Calot's triangle¹⁸ dissociation. Take care to ligate the cystic duct and artery with medium-sized hemostatic clips, do not cut the gallbladder, and leave the gallbladder in situ primarily (Figure 3).
2. Segment the round and falciform ligaments with the harmonic scalpel. Separate the left coronary and triangular ligaments carefully, avoiding injury to the adjacent phrenic vein branches (Figure 4). Then, incisethe hepatogastric ligaments medially 10 mm into the lesser sac.
3. Access from left to right behind the hepatoduodenal ligament through a sling removed from the attached 14 F single-lumen catheter to prepare for hepatic inflow occlusion (Figure 5).
4. After ligating the left hepatic artery with medium-sized vascular clips, ensure that the first porta hepatis has been blocked with the single-lumen catheter to prevent unexpected bleeding during the mobilization of the left hepatic pedicle.
   1. Gently lift the inferior edge of the liver, free the left Glissonean pedicles by the gap of the Laennec membrane¹⁹ and Hilar plate²⁰ (Figure 6), and then prepare a tourniquet system to block the left hepatic inflow by inserting an 8 F single lumen catheter through the left Glissonean pedicle²¹ (Figure 7).
5. After releasing the first porta hepatis, block the left hepatic pedicle by clamping the single lumen catheter with a hemostatic clip (Figure 8), which will be stapled after parenchyma transection. Determine the border between the left and right hepatic lobes by identifying ischemia of the left hepatic lobe.
   1. Following the dividing line, seek and mark the projection positions of the middle hepatic veins with laparoscopic ultrasonography. Pay attention to mapping the location and trajectories of the vital intrahepatic vessels, especially those located on the expected transverse plane of the liver parenchyma (Figure 9).
      NOTE: In this study, the ultrasound was set to color Doppler flow image (CDFI) mode, and the thin-walled vessel flowing into the inferior vena cava in the same direction as the long axis of the ultrasound probe was judged to be the MHV. Moreover, it was also located near the dividing line.
6. Mark the parenchymal transection line with an electric hook along the demarcation line on the liver surface (Figure 10). Ask the assistant to drag the fundus of the gallbladder and transect the parenchyma from the foot side to the head side along the middle hepatic vein using an ultrasonic scalpel (Figure 11).
   1. Trigger the ultrasonic scalpel early to effectively reduce hepatic parenchymal bleeding, and do not clamp the tip of the scalpel to avoid vessel damage. Secure or suture the large intrahepatic vessels and bile ducts found during the parenchymal resection with 2-0 sutures if necessary.
7. Expose the vascular pedicles inflowing into segments 4a/4b and the left hepatic vein further up in the cutting line (Figure 12). Then, expose the whole MHV and its tributaries fully, and dissect the roots of the LHV and MHV later (Figure 13). Lastly, staple the inflow and outflow vessels with the powered plus stapler when exposed.
8. Once the liver specimens have been isolated from the remaining right hepatic lobe, conduct a hemostasis and bile leakage examination along the cut surface before suturing.
   1. Use monopole electrocoagulation (see Table of Materials) for hemostasis when bleeding spots are found on the cut surface (Figure 14). Wrap the resected left hepatic lobe (Figure 15) in a plastic bag, and take it out through a 4 cm long incision in the lower abdomen, followed by the placement of two drainage tubes.

3. Postoperative nursing

1. On the first postoperative day, discontinue the nasogastric tube, and give the patient a liquid diet.
2. Remove the Foley catheter on postoperative day 2, and assist the patient in getting out of bed for daily activities.
3. Finally, when the drainage is less than 50 mL per day, remove the two drainage tubes on the fourth and fifth days, respectively. Ask the patient to return to the hospital for a follow-up examination 1 month later.

Results

The duration of the operation was 255 min, no complications were observed during the operation, and the estimated blood loss was less than 20 mL. The operation was not converted to open surgery, and no postoperative complications were seen. Liver segment 2, liver segment 3, and liver segment 4 (including the gallbladder) were resected anatomically, and the MHV as well as its tributaries (V5v, ventral branch of the fifth segment of the hepatic vein; V8v, ventral branch of the eigth segment of the hepatic vein) were comple...

Discussion

Anatomic hepatectomy is a procedure that can simultaneously remove the lesion and the liver segments along with the corresponding veins and has been considered an ideal method for treating liver cancer^23,24,25,26. With technological innovation, anatomic liver resection with laparoscopic technology has developed rapidly as an alternative to conventional open liver resection and is now widely acc...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
30° Laparoscopy	Olympus Corporation	CV-190
Harmonic Ace Ultrasonic Surgical Devices	Ethicon Endo-Surgery, LLC	HAR36
Laparoscopic ultrasonography	Hitachi	Arietta 60
Monopole electrocoagulation	Kangji Medical	/
Nasogastric tube	Pacific Hospital Supply Co. Ltd	I02705
Powered plus stapler	Ethicon Endo-Surgery, LLC	PSEE60A
Single lumen ureter	Well Lead Medical CO, LTD	14F,8F
Trocar	Surgaid Medical	NPCM-100-1-10
Vascular clips	Teleflex Medical	544243