Perioperative management of acute kidney injury after microwave ablation of hepatic hemangioma

Abstract

Objective

To improve treatment options for acute kidney injury (AKI) after microwave ablation (MWA) of hepatic hemangioma (HH).

Methods

From January 1, 2021, to October 28, 2024, 117 patients with HH were treated by MWA at our center, and 2 of them occurred AKI after operation. The preoperative and postoperative data of 2 patients were retrospectively analyzed.

Results

During the MWA for patients with HH, hemoglobinuria may occur during and after surgery, which may even lead to AKI. A sequential treatment consisting of sodium bicarbonate alkalization, rapid fluid replacement, diuresis and dialysis treatment were given to the patient as early and timely. And their renal function returned to normal.

Conclusion

Patients with AKI after MWA of HH can fully recover. It suggested that MWA is an effective and safe treatment for HH patients.

Background

Hepatic hemangioma (HH) is a common benign tumor of the liver that is discovered in most patients through physical examination. HH has no tendency to undergo malignant transformation. As the hemangioma progresses, it can cause corresponding symptoms of abdominal discomfort [1, 2]. In 2014, the American College of Gastroenterology (ACG) proposed that surgical treatment can be considered for patients with HH with a diameter of > 10 cm or symptoms of oppression and pain [3]. Traditional surgeries involve large surgical incisions, high risks, and slow postoperative recovery and are prone to complications such as bleeding [4, 5]. Our team has been engaged in tumor ablation therapy for 26 years, and the first ablation surgery was completed in 1999. More than 2,000 ablation surgeries have been performed. In the early stage, we mainly performed thermal ablation surgery for liver cancer, and published several related academic reports [6,7,8,9,10,11]. Due to the large number of patients with HH in China, in the past 10 years, we have begun to gradually explore the thermal ablation treatment of HH with our previous experience in ablation surgery, and have achieved good results.

The principle of MWA is as follows: a microwave electric field is used to make molecules move at high speeds with a microwave frequency, and the molecules rub against each other to generate a high-energy thermal effect, thereby coagulating the target tissue and causing coagulative necrosis [12]. Because MWA has the advantages of high safety, minimal trauma, and fast postoperative recovery, it is widely used in clinical practice [13,14,15]. MWA has also been confirmed to be effective in treating HH with favorable clinical outcomes. However, MWA can lead to acute kidney injury (AKI), and current research lacks a systematic evaluation of AKI and clinical therapies for this complication [16, 17]. In our center, from January 1, 2021, to October 28, 2024, 117 patients with HH were admitted. All patients underwent laparoscopy combined with ultrasound-guided one-off complete MWA. Two patients developed AKI, and their renal function returned to normal after active symptomatic treatment. The data of 2 patients were retrospectively analyzed, and here the clinical experience is summarized with the aim of providing a reference for the subsequent treatment of HH through MWA.

Methods

One hundred and seventeen patients diagnosed with HH were admitted to our hospital from January 1, 2021, to October 28, 2024. All patients had HH > 10 cm in diameter and underwent laparoscopy combined with ultrasound-guided one-off complete MWA according to the protocol in the flowchart (Fig. 1). In particular, there were two patients among them developed AKI after MWA, and their renal function returned to normal after active symptomatic treatment. Contrast-enhanced computed tomography (CT) scans showed a giant hemangioma with a maximum diameter of 136 mm in the first patient (Fig. 2A, B) with a history of gallstones combined with cholecystitis, hypertension and diabetes. The second patient had a hepatic hemangioma with a maximum diameter of 104 mm on contrast-enhanced magnetic resonance imaging (MRI), (Fig. 3A, B) and suffered from hypertension, hyperlipidemia, and myocardial hypertrophy. No obvious positive signs were found in the hospital examination.

Fig. 1

A flowchart summarizing patient selection and treatment

Fig. 2

The imaging data changes of the first patient. A and B are preoperative contrast-enhanced computed tomography (CT) scans of the abdomen, and the maximum diameter of the hemangioma is 136 mm; C is a CT scan of the abdomen 3 days after surgery, and the diameter of the hemangioma is 76 mm

Fig. 3

The imaging data changes of the second patient. A and B are preoperative contrast-enhanced magnetic resonance imaging (MRI) images of the abdomen, and the maximum diameter of the hemangioma is 104 mm; C is a computed tomography (CT) scan of the abdomen 2 days after surgery, and the diameter of the hemangioma is 52 mm

On the 4th day after admission, with the guidance of digital subtraction angiography (DSA) under local anesthesia, superselective hepatic artery embolization was performed to embolize the branch of the artery feeding the HH. On Day 8 after admission, under general anesthesia, laparoscopy combined with ultrasound-guided MWA treatment of the HH was performed, particularly the first patient also underwent a concurrent cholecystectomy. A urinary catheter was routinely placed in all patients during surgery. During MWA (MWA system produced by Nanjing Kangyou Co., Ltd., model KY-2000; electrode produced by Nanjing Kangyou Co., Ltd., model KY-2450B-T7), with laparoscopic assistance and ultrasound localization, the HH was ablated. The intraoperative ablation power was 60–70 W, the first patient’s ablation time was 60 min, the intraoperative rehydration amount was 1,500 ml, the urinary output was 120 ml, and the second patient’s ablation time was 26 min, the intraoperative rehydration amount was 1,000 ml, the urinary output was 100 ml. No significant hemoglobinuria was observed in both patients during surgery. Postoperative, 2 patients developed AKI. A sequential treatment consisting of sodium bicarbonate alkalization, rapid fluid replacement, diuresis and dialysis treatment were given to the patient as early and timely. Changes in liver and renal function parameters and hemoglobin (HB) and B-type natriuretic peptide (BNP) and urine output levels before and after surgery were analyzed, and changes in HH according to abdominal imaging data obtained before and after surgery were analyzed. All patients were informed with consent according to protocols approved by the Institutional Review Board of the PLA general Hospital, and this study abide by the ethical guidelines of the Helsinki Declaration.

Results

The size of hepatic hemangiomas significantly decreased in both patients, 76 mm and 52 mm showing on CT scan respectively on the third and second day after surgery (Figs. 2C and 3C). Postoperative, liver and renal insufficiency occurred, and BNP levels increased (Tables 1 and 2). Hepatoprotective therapy was implemented from the day of surgery. The levels of ALT, AST, TBIL, and DBIL reached their highest level on the first postoperative day in both patients, then gradually decreased, and returned to preoperative levels on the 7th and 11th postoperative day (Tables 1 and 2; Figs. 4A and B and 5A and B). Changes in HB were also measured. Unlike previous studies, there was no significant decrease in HB in our patients after surgery (Figs. 4C and 5C).

Table 1 Clinical parameters of patient 1

Table 2 Clinical parameters of patient 2

Fig. 4

Changes in observation indicators before and after surgery for the first patient. A and B show the trends in ALT and AST levels; postoperatively, liver function was affected, and the recovery was fast. C shows the change trend of HB levels. The HB level decreased slightly after surgery. D shows the urine output on the day of surgery and after surgery. After surgery, a period of oliguria occurred. The urine output gradually returned to normal after dialysis treatment. E and F show the changes in CR and BNP levels, respectively. After dialysis treatment, CR and BNP gradually returned to their preoperative levels

Fig. 5

Changes in observation indicators before and after surgery for the second patient. A and B show the trends in AST and ALT levels; postoperatively, liver function was affected, but liver function parameters rapidly recovered; C shows the trend of HB levels. The HB level decreased after surgery, but the postoperative decrease was not significant. D is the urine output on the day of surgery and after surgery, and there was no significant period of oliguria after surgery. E and F show the changes in CR and BNP levels, respectively. After symptomatic and supportive treatment, CR and BNP levels gradually recovered to their preoperative levels

AKI is defined by rapid deterioration of renal excretory function, diagnosed by the accumulation of end products of nitrogen metabolism (creatinine, 2-fold increase) and/or decreased urine output (UO < 0.5 ml/kg/h for 12 h) [18]. The levels of creatinine (CR) showed a progressive increase from the first postoperative day (Tables 1 and 2). Two patients were definitively diagnosed with AKI, and sodium bicarbonate alkalization, rapid fluid replacement, diuresis and dialysis treatment were given to the patient timely. Further analysis found that changes in CR, urine output, and BNP were not exactly the same in the two patients. In the first patient, he had little urine output after surgery. Sodium bicarbonate alkalization, rapid fluid replacement, and diuresis were given timely to him. But the urine output was still low, and there was a soy sauce color and contained sediment in the urine. The urine output on the day of surgery was only 400 ml. CR level progressively increased. With the increase of rapid fluid replacement and the decrease of urine, the patient’s BNP level increased. Considering the patient’s oliguria, after consultation with his family and the nephrology department, dialysis treatment was initiated on the 3rd day after surgery. After seven dialysis sessions, urine output began to increase on the 13th day after surgery, and Cr and BNP levels gradually decreased to preoperative levels (Fig. 4D, E, F). The second patient also had little urine output during operation. However, with treatments such as sodium bicarbonate alkalization, rapid fluid replacement, and diuresis, the patient’s urine output increased. The color of the urine initially was light red and then became clear quickly. The urine output on the day of surgery was 1340 ml. Although the postoperative urine output remained normal (Fig. 5D), the Cr level still progressively increased. The patient had hypertrophic cardiomyopathy, and the BNP level was persistently increased. We believed that the perfusion therapy affected the patient’s cardiac function. After consultation with her family and the nephrology department, the patient underwent one round of dialysis on Day 5 after surgery. The patient could not tolerate the fear during the dialysis process, so no additional rounds of dialysis were performed. The Cr and BNP levels gradually decreased to preoperative levels (Fig. 5E, F).

Discussion

HH is currently generally considered a vascular malformation caused by excessive development or abnormal differentiation of blood vessels during embryonic development [19]. As the volume of HH increases, adjacent tissues and organs in the abdominal cavity are affected, which leads to abdominal discomfort, such as abdominal pain, abdominal distension and other related symptoms [1, 2]. In some cases, the HH ruptures due to the weak arterial wall or external force, which can be life-threatening in severe cases [20, 21]. The clinical treatment of HH is currently controversial, and follow-up observation is often the choice [22]. In 2014, the ACG proposed that surgical treatment can be considered for patients with HH with a diameter of > 10 cm or symptoms of oppression and pain [3]. Surgery is the most effective treatment for HH. Traditional surgical methods include open or laparoscopic surgical resection [23]. However, surgical trauma and risk are high, postoperative recovery is slow, and complications such as bleeding are prone to occur [4, 5]. With the growth of HH, there would be corresponding abdominal discomfort symptoms, the risk and difficulty of surgery would increase. Previous studies have suggested that HH with a diameter of more than 5 cm could be considered for surgical treatment [2, 24]. We believe that HH with a diameter of ≥ 5 cm that is consistently increasing can be treated with minimally invasive surgical intervention early to avoid surgical resection. Based on the characteristics of benign lesions of HH, under the premise of strictly controlling the indications for treatment, the principle should be to achieve the best therapeutic effect with the least amount of trauma [25].

The use of ablation for HH has been reported in previous studies [14]. Thermal ablation can cause the destruction of many RBCs, which could cause intravascular hemolysis. After surgery, there is a sudden decrease in HB levels, which can lead to different degrees of hemoglobinuria and even AKI [26]. Studies have revealed a strong correlation with the size of the hemangioma and the time of ablation, leading researchers to recommend multiple ablations [27,28,29]. In our center, MWA is used for HH, and significant results have been achieved. After continuous practice, when MWA is used for one-off complete ablation of HH, obvious reduction of the tumor, minimal surgical trauma, and no serious postoperative complications can be achieved. Moreover, we have found that HB levels did not significantly decrease during the first three days. We believe that the thermal ablation destructed RBC in HH.

The analysis of the clinical data of patients with renal insufficiency after MWA revealed that renal insufficiency was completely reversible. We believe that the thermal effect causes damage to the blood of the HH and the destruction of blood cells during MWA. In particular, HB is released after the destruction of RBCs. If the number of destroyed RBCs is large and the amount of HB released exceeds the metabolic capacity, hemoglobinuria could develop. In most patients, hemoglobinuria is transient. After adequate fluid replacement, urine alkalinization, and diuretic treatment, the urine output can return to normal without renal function being affected. If RBCs are severely destroyed during surgery, large amounts of free HB accumulate in the body, which may block renal tubules and induce AKI. In this study, Patient 2 did not have significant oliguria after surgery, but there was a progressive increase in Cr level after surgery. We also found that the BNP level increased after surgery. Given that the patient was complicated with hypertrophic cardiomyopathy, she received dialysis treatment only once and was subsequently treated with fluid replacement and urine alkalinization, and the Cr and BNP levels gradually decreased and recovered to the preoperative levels. After surgery, the first patient had soy sauce-colored urine, a significant period of oliguria, and a progressive increase in the Cr level. After 7 cycles of dialysis treatment in the department of nephrology in our hospital, renal function gradually improved, and urine output returned to normal.

Through the data analysis and the efficacy evaluation of other patients, to avoid the occurrence of hemoglobinuria and AKI, we took the following measures: a, When performing MWA for large hemangiomas, interventional embolization should be routinely performed prior to the surgery to embolize the blood supplying arterial branches of the HH individually to block the blood supply to the HH, thus reducing the number of RBCs destroyed. b, On the day of surgery, adequate fluid replacement therapy should be administered before and during the operation to maintain adequate renal perfusion, and a urinary catheter should be routinely placed during the operation. If low urine output occurs, sodium bicarbonate should be given to alkalinize the urine, and diuretic treatment should be given to eliminate the free HB on the premise of adequate fluid replacement. Therefore, when hemoglobinuria is seen during the operation, it is not a cause for alarm, because only when the free HB is discharged in time, it is possible that AKI will not occur. c, If AKI occurred, as indicated by oliguria and anuria, occurs after surgery, dialysis should be performed as soon as possible. On the basis of these findings, subsequent patients with HH treated with MWA at our center underwent one round of complete ablation. Although transient hemoglobinuria may have occurred during surgery and after surgery, none of the patients had AKI.

In summary, during the perioperative period of MWA for HH, with close patient monitoring and management, the occurrence of hemoglobinuria and AKI can be avoided. If hemoglobinuria or even AKI occurs after surgery, renal insufficiency can be completely reversed with timely and correct treatments.