Application of Microwave Ablation in Laparoscopic Partial Splenectomy

Summary

The use of laparoscopic partial splenectomy has been limited due to the high risk of bleeding during surgery. Therefore, we introduce a laparoscopic method combined with microwave ablation to solve the problem of intraoperative bleeding.

Abstract

Splenic hemangioma is the most common pathological classification of splenic tumors, and its surgical indication and treatment have been controversial. Before, open splenectomy was usually used to treat splenic hemangioma. Following the rapid development of laparoscopic techniques, people's requirements for minimally invasive treatment have gradually increased, and laparoscopic splenectomy has gradually become the main treatment method. However, through the deeper study of spleen function, it was found that partial splenectomy can cut down the incidence of postoperative thrombocythemia and decrease side effects on the physiological function of the body, so laparoscopic partial splenectomy came into being. However, due to the special anatomical structure, the incidence of hemorrhage during partial splenectomy is greater. Therefore, during the operation, we removed part of the splenic blood vessels, combined with microwave ablation, which perfectly solved the problem of intraoperative bleeding. Laparoscopic partial splenectomy combined with microwave ablation not only achieves the requirements of minimally invasive treatment but also reduces the risk of intraoperative bleeding, meriting clinical application and promotion.

Introduction

Benign splenic lesions generally do not require surgical intervention, and regular follow-up is the mainstay. Surgery is indicated when they become larger than 40 mm in diameter or cause clinical symptoms¹. For benign splenic mass lesions, total splenectomy is the mainstay of surgery, and laparoscopic total splenectomy (LTS) has long been considered a standard surgical procedure. The advantages of this technique over open surgery are indisputable². However, total splenectomy can lead to complications such as decreased immunity, venous thrombosis, and infection after overwhelming splenectomy^3,4,5, which seriously affects the prognosis of patients. With the in-depth study of spleen function and anatomy, laparoscopic partial splenectomy (LPS), which preserves part of the spleen function, has been widely used in clinical practice^6,7, but there is still no consensus on whether LPS is superior to LTS for benign splenic tumors. Because of the fragility of spleen tissue, which makes it much more difficult to suture, LPS has a higher risk of bleeding than LTS⁸. Therefore, how to reduce intraoperative bleeding is a key issue in the implementation of LPS.

Microwave ablation (MVA) can be used to control life-threatening bleeding by rapidly raising the local temperature of the target tissue above 60 °C. It has been used as a means of hemostasis in a variety of solid tumor needle biopsies and laparoscopic hepatectomy^{9,10,11,12,13}. At present, LPS assisted by MVA is still rarely reported.

In this study, we performed LPS by blocking blood flow in the area where the tumor is located and then using MVA to coagulate the spleen tissue at the plane of the ischemic line, and finally successfully completed the operation. This approach preserves some splenic function and reduces intraoperative blood loss, which decreases the postoperative complication rate after splenectomy.

CASE PRESENTATION:The patient, a 48-year-old woman, complained of left upper quadrant pain for more than 7 years, had a history of hypertension, and denied a history of abdominal surgery. Computed tomography (CT) and contrast-enhanced scan of the upper abdomen in the outer hospital showed that there was a slightly low-density nodule in the spleen, and it was more likely to be considered a hemangioma.

Diagnosis, Assessment, and Plan:
After admission, ultrasound and MRI of the upper abdomen were completed to preliminarily diagnose splenic hemangioma. Considering that the patient's tumor diameter was greater than 5 cm and accompanied by abdominal pain, a partial splenectomy was planned

Protocol

This protocol meets the norms and requirements of the Medical Ethics Committee of the First Affiliated Hospital of Jinan University, and the informed consent of the patient has been obtained.

1. Preoperative examination

1. Determine the location and size of the tumor and blood vessels (Splenic arteriovenous branches) supplying the tumor according to the preoperative CT or MRI, and then plan the resection range and microwave ablation plane. Here, only an MRI was performed before the operation (Figure 1), and it was determined that the tumor was located at the lower pole of the spleen and supplied by the branch of the lower pole of the splenic artery.
2. Use the following inclusion criteria: Age 18-75 years; preoperative imaging examination shows a benign occupancy of the spleen, and the diameter of the spleen occupancy mass is ≥ 5 cm, or it is combined with clinical symptoms such as abdominal pain and bloating; the tumor is confined to the upper or lower pole of the spleen and does not involve the splenic arteriovenous vessels.
3. Use the following exclusion criteria: A history of blood system-related diseases; spleen lesions caused by other causes (such as portal hypertension, pancreatic disease, malaria, splenic rupture, splenic malignancy, etc.).

2. Anesthesia and preoperative preparation

1. Use Endotracheal intubation for general anesthesia. At the same time, perform internal jugular venipuncture to place a 7 Fr intravenous catheter with ultrasound guidance and puncture the radial artery with a 21 G arterial indwelling needle for arterial pressure detection.
2. Indwell a 16Fr gastric tube and a 16Fr urinary tube. Administer antibiotics (Latoxef 1 g) 30 min before surgery to prevent infection.
3. Let the patient lie down tilted to the right with the head upper than the feet and the lower limbs spread 50°-60°.  Adjust the position in time according to the intraoperative situation.

3. Surgical procedure

1. Operator position: The first surgeon stands on the patient's right side, while the second is located on the opposite side, and the camera operator stands between the legs (Figure 2).
2. Trocar hole layout: Set and maintain a pneumoperitoneum pressure of 12 mmHg. Establish a 10 mm observation hole at the lower umbilical margin using the 5-hole method and implant into it a 30° laparoscope. Establish a 12 mm primary operating hole at the right linea pararectalis umbilicus level, and 5 mm auxiliary operating holes at the right mid-clavicular line below the costal margin, the left anterior axillary line below the costal margin, and left linea pararectalis umbilicus level. Adjust the position of the trocar or increase its number if necessary, during the operation.
   NOTE: In the case of the four-hole method, the observation hole is still located at the lower edge of the umbilicus. Establish two 10 mm primary operating holes at the midpoint of the line connecting the xiphoid process to the umbilicus and left anterior axillary line umbilicus level, respectively. Set five 5 mm auxiliary operating holes at the left mid-clavicular line umbilicus level.
3. Surgical procedures
   1. Open the left gastrocolic ligament with an ultrasonic knife and separate the gastrosplenic ligament to reveal the splenic portal (Figure 3A). Pay attention to ligating the short gastric arteries while dissecting the gastrosplenic ligament.
   2. Isolate the lower pole branch of the spleen pedicle and then ligate them with Hem-o-Lok clamps (Figure 3B-C). Dissect the splenic artery to find the branches of the blood vessels supplying the tumor if necessary.
   3. Reveal the splenic hemangioma (Figure 3D). Separate the splenocolic ligaments (on the lower outer side of the spleen, Figure 3E) and splenorenal ligaments (behind the spleen, Figure 3F) to make the target area fully free.
   4. Identify the ischemic line between normal spleen tissue and the fraction lacking blood supply (Figure 3G).
   5. Insert the percutaneous microwave ablation needle and coagulate the spleen tissue by microwave ablation along the ischemic line in phases and gradually, with the power of 60-80 W. Adjust the time according to the specific injection position and depth (Figure 3H-I). The time per ablation is about 3 min. Ensure that the tip of the needle does not penetrate the spleen parenchyma, and that the ablation area is in the same plane.
   6. Divide the splenic along the coagulation zone (Figure 3J). Check for bleeding in the splenic section and observe the blood supply of the residual spleen (Figure 3K).
   7. Place the splenic fossa drainage tube (Figure 3L) and remove the splenic tumor specimens from the extended umbilical incision. Use layered sutures to suture the surgical incision, and the surgery is over.

4. Post-surgical procedures

1. Perform H&E staining and immunohistochemical (IHC) staining on splenic mass specimens to confirm the diagnosis.
2. Recheck the blood sample on the 1^st, 3^rd, and 7^th days after surgery, followed by a weekly blood checkup. Use aspirin if persistently elevated platelets are found. Continue antibiotics for 3 days after surgery to prevent infection. Patients are usually hospitalized for 1-2 weeks after surgery, and re-examination is done using abdominal CT 1 month after surgery.

Results

The lower pole of the splenic, including the tumor, was resected in about 3 h with 100 mL of hemorrhage. The patient recovered without complications such as pancreatic leakage, intestinal leakage, splenic effusion, and portal vein thrombosis.

H&E and CD34 IHC staining was used to determine the postoperative pathology as splenic hemangioma with focal infarction (Figure 4A-C).

After discharge, the patient returned to ...

Discussion

The selection of appropriate cases is the first step in the successful development of LPS. Based on personal experience and literature reports, we summarize the following indications^14,15: (1) The tumor is located in the upper or lower pole of the spleen and away from the splenic hilum. (2) There is no serious adhesion between the tumor and surrounding tissues. (3) The retained spleen volume should be at least 25% of the original volume. (4) No coagulation dysfun...

Materials

Name	Company	Catalog Number	Comments
10-mm trocar	Xiamen Surgaid Medical Device Co., LTD	NGCS 100-1-10	Sterile, ethylene oxide sterilized, disposable
12-mm trocar	Xiamen Surgaid Medical Device Co., LTD	NGCS 100-1-12	Sterile, ethylene oxide sterilized, disposable
5-mm trocar	Xiamen Surgaid Medical Device Co., LTD	NGCS 100-1-5	Sterile, ethylene oxide sterilized, disposable
Hem-o-lok	America Teleflex Medical Technology Co., LTD	544240	Sterile, ethylene oxide sterilized, disposable
Pneumoperitoneum needle	Xiamen Surgaid Medical Device Co., LTD	NGCS 100-1	Sterile, ethylene oxide sterilized, disposable
Suction and irrigation tube	Tonglu Hengfeng Medical Device Co., LTD	HF6518.035	Sterile,dry heat sterilized, reusable
Ultrasounic-harmonic scalpel	Chongqing Maikewei Medical Technology Co., LTD	QUHS36S	Sterile, ethylene oxide sterilized, disposable
Water-cooled microwave ablation probe(single use)	Nanjing Viking Jiuzhou Medical Device R&D Center	MTC-3CA-II19	Sterile, ethylene oxide sterilized, disposable