Experimental study on the feasibility and safety of radiofrequency ablation for secondary splenomagely and hypersplenism

US-guided percutaneous microwave ablation (MWA) of submandibular gland: A new minimal invasive and effective treatment for refractory sialorrhea and treatment response evaluation with contrast-enhanced imaging techniques

A 33 years' old male complained of excessive salivation with frequent swallowing and spitting, which resulted in communication disturbance, reduced quality of life, and social embarrassment for 19 years. He had been diagnosed as sialorrhea and submandibular gland hyperfunction by stomatologist, then had unilateral submandibular gland resection 13 years ago, but the symptom relief was not satisfactory. After that, he had been treated with glycopyrrolate for less than a year, which was withdrawn because of the short duration of symptomatic control after each tablet take-in and intolerable side effects. With the wish to receive a new treatment with long term effectiveness, low re-operation risk and normal preserved saliva secretion function, the patient was subject to MWA for the right submandibular gland. After systematic clinical evaluation, US-guided percutaneous MWA was successfully performed with an uneventful post-operative course. The volume of the right submandibular gland and ablated area were measured precisely by an ablation planning software system with automatic volume measurement function based on three-dimensional reconstruction of the pre-operative and post-operative enhanced magnetic resonance imaging (MRI) raw data. Finally, the ablated volume was calculated as 62.2% of the whole right submandibular gland. The patient was discharged 1 day after the operation, with symptoms relieved significantly, the mean value of whole saliva flow rate (SFR) decreased from 11 ml to 7.5 ml per 15 minutes. During the follow up by phone three months after operation, the patient reported that the treatment effect was satisfactory, whereas the SFR value became stable as 7 ml per 15 minutes, drooling frequency and drooling severity (DFDS) score decreased from 6 to 5, drooling impact scale (DIS) score decreased from 43 to 26. US-guided percutaneous MWA of submandibular gland seems to be an alternative, minimal invasive, and effective treatment for refractory sialorrhea.We described a patient with refractory sialorrhea treated successfully with ultrasound (US) guided percutaneous microwave ablation (MWA).

Preliminary experimental study on splenic hemodynamics of radiofrequency ablation for the spleen

PURPOSE

To test the splenic blood flow change after radiofrequency ablation (RFA) of the spleen in a porcine experimental model.

MATERIAL AND METHODS

Six pigs underwent RFA of the spleen via laparotomy. During the procedure of RFA, clamping of splenic artery (one) and both splenic artery/vein (one) was also performed. Measurement of blood flow of both splenic artery (SA) and splenic vein (SV) with flow-wire at pre- and post-RFA of the spleen was also performed.

RESULTS

Ablated splenic lesions were created as estimating ∼50% area of the spleen in all pigs. Resected specimens reveal not only the coagulated necrosis but also the congestion of the spleen. On the SA hemodynamics, maximum peak velocity (MPV) changed from 37 ± 7 to 24 ± 8 cm/s (normal), 11 to 10 cm/s (clamp of the SA), and 12 to 7.5 cm/s (clamp of both SA/SV), respectively. On the SV hemodynamic, MPV changed from 15 ± 5 to 13 ± 4 cm/s (normal), 17 to 15 cm/s (clamp of the SA), and 17 to 26 cm/s (clamp of both SA/SV), respectively.

CONCLUSIONS

RFA of the spleen could induce coagulation necrosis and reduce the splenic arterial blood flow.

Hepatectomy combined with microwave ablation of the spleen for treatment of hepatocellular carcinoma complicated with splenomegaly: A retrospective study

The present retrospective study aimed to investigate the mid-term safety and efficacy of hepatectomy combined with microwave ablation of the partial spleen for treatment of liver cancer complicated with hypersplenism. A retrospective analysis was performed on 23 patients who underwent hepatectomy combined with microwave ablation of the partial spleen for liver cancer, complicated with hypersplenism that was secondary to cirrhosis. The splenic and ablated volumes were calculated according to a contrast-enhanced computed tomography scan prior to and 2 weeks after the operation. Complete blood count and liver function tests were examined prior to and following the surgery, and complications and changes in the blood tests were monitored for 6 months. Over this period of investigation, the splenic volume was reduced by a mean value of 34.0%. The levels of serum alanine aminotransferase and aspartate aminotransferase were increased on the first day after the operation (P<0.05), although they recovered to the normal level within 1 week (P<0.05). The total level of bilirubin increased slightly, along with moderately decreased levels of albumin and cholinesterase on the first day, although these changes were not significant compared with the baseline (P>0.05). The white blood cell count was persistently significantly higher compared with the baseline over the course of the 6 months (P>0.05). The platelet count did not increase significantly for the first week after the operation (P>0.05); however, it was revealed to be significantly increased 1 month after the surgery (P<0.05). No significant complications were occurred during the follow-up period. In conclusion, hepatectomy combined with microwave ablation of the spleen was demonstrated to be a safe and effective procedure for patients with liver cancer and hypersplenism in the mid-term.

A Comparative Study of Surgical Splenectomy, Partial Splenic Embolization, and High-Intensity Focused Ultrasound for Hypersplenism

OBJECTIVES

This study compared splenectomy, partial splenic embolization, and high-intensity focused ultrasound (HIFU) therapy, which represent the traditional, mature, and newest methods for improving thrombocytopenia in hypersplenism, respectively.

METHODS

A total of 69 patients with hypersplenism were treated with surgical splenectomy (n = 31), HIFU (n = 26), or partial splenic embolization (n = 12). They were followed closely for at least 6 months, and the effectiveness of the treatments was compared.

RESULTS

Among the 3 groups, splenectomy was the most effective treatment for increasing peripheral blood cells. Embolization reduced the operating time and hospital stay, but HIFU was relatively safer and less invasive than the other treatments.

CONCLUSIONS

High-intensity focused ultrasound has wide clinical indications for hypersplenism and may be safer than other treatment methods. Therefore, it is a good alternative procedure for patients with a high surgical risk.

Comparison of 3D ultrasound and magnetic resonance imaging for microwave ablation in the canine splenomegaly model

PURPOSE

Microwave ablation is used for the treatment of hypersplenism. Image guidance and ablation volume assessment is important to ensure that the ablation is successful. The accuracy of 3D ultrasound (US) and magnetic resonance imaging (MRI) in determining the parameters for microwave ablation were compared in a canine splenomegaly model.

METHODS

Microwave ablation of the spleen was performed on 13 dogs with congestive splenomegaly. Several combinations of power output and ablation time were used: 60 W for 300 s, 50 W for 360 s and 40 W for 450 s. The ablation zone volume was measured by 3D US and 3D MRI immediately after microwave ablation, and at 1, 2 and 8 weeks thereafter.

RESULTS

Compared with 3D MRI, the ablation zone reconstruction rate was lower with 3D US (92 vs. 100%). However, there was no significant difference was found in the ablation volume calculated soon after the treatment and 1 week and 2 months later.

CONCLUSION

3D US may be useful for quantifying the volume of microwave ablation zones in the spleens of experimental animals and appears promising as an alterative modality to MRI for clinical examinations.

Experimental studies and clinical experiences on treatment of secondary hypersplenism with extracorporeal high-intensity focused ultrasound

The aim of this study is to investigate the efficacy and safety of extracorporeal high-intensity focused ultrasound (HIFU) in treatment of hypersplenism. Fifteen adult dogs, weighing 13-18 kg were divided into three groups: sham group, SVL group undergoing splenic vein ligation (SVL) after laparotomy, and SVL + HIFU group receiving SVL followed by extracorporeal HIFU. Pathologic and hematologic analyses were performed. We also reviewed the clinical data of 19 patients with secondary hypersplenism caused by liver cirrhosis or hepatocellular carcinoma who underwent extracorporeal HIFU. Extracorporeal HIFU significantly diminished the volume of the spleen of animals, coupled with occurrence of coagulation necrosis and fibrosis in the target area. Both platelet and red blood cell counts were significantly restored by HIFU intervention. Similarly, HIFU treatment improved the hematologic parameters in patients with hypersplenism, and no major complications were encountered. Extracorporeal HIFU intervention is effective and safe in managing secondary hypersplenism.

Experimental study of destruction to porcine spleen in vivo by microwave ablation

AIM: To discuss the safety, feasibility and regularity of destruction to porcine spleen in vivo with congestion and tumescence by microwave ablation (MWA).

METHODS: Ligation of the splenic vein was used to induce congestion and tumescence in vivo in five porcine spleens, and microwave ablation was performed 2-4 h later. A total of 56 ablation points were ablated and the ablation powers were 30-100 W. The ablation time (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 min) was performed at a power of 60 W. After ablation, the ablation size was measured in pigs A, C, D and E and spleen resection. In pig B, the ablation size was measured and 2 ablation points were sent for pathology analysis and all tissues were sutured following ablation. Pig B was killed 1 wk later and the ablation points were sent for pathology analysis. Bleeding, tissue carbonization surrounding electrodes, and pathological changes were observed, and the effect on destruction volume relative to different ablation powers, times and positions was analyzed.

RESULTS: The incidence of bleeding (only small am-ounts, < 20 mL) in the course of ablation was 5.4% (3/56) and was attributed to tissue carbonization surrounding electrodes, which also exhibited an incidence of 5.4% (3/56). The destruction volume was influenced by different ablation powers, times and points. It showed that the ablation lesion size increased with increased ablation time, from 1 to 10 min, when the ablation power was 60 W. Also, the ablation lesion size increased with the increase of ablation power, ranging from 30 to 100 W when the ablation time was set to 3 min. A direct correlation was seen between the destruction volume and ablation time by the power of 60 W (r = 0.97542, P < 0.0001, and also between the destruction volume and ablation powers at an ablation time of 3 min (r = 0.98258, P < 0.0001). The destruction volume of zone II (the extra-2/3 part of the spleen, relative to the first or second class vascular branches), which was near the hilum of the spleen, was noteably larger than the destruction volume of zoneI(the intra-1/3 part of the spleen) which was distal from the hilum of the spleen (P = 0.0015). Pathological changes of ablation occurring immediately and 1 wk after MWA showed large areas of coagulation. Immediately following ablation, intact spleen tissues were observed in the areas of coagulation necrosis, mainly around arterioles, and there were no obvious signs of hydropsia and inflammation, while 1 wk following the ablation, the coagulation necrosis was well distributed and complete, as many nuclear fragmentations were detected, and there were obvious signs of hydropsia and inflammation.

CONCLUSION: In vivo treatment of congestion and tumescence in the spleen using microwave ablation of water-cooled antenna is a safe and feasible method that is minimally invasive.

Randomized clinical trial of splenic radiofrequency ablation versus splenectomy for severe hypersplenism

BACKGROUND

Radiofrequency ablation (RFA) is a relatively new treatment for hypersplenism. The results of a randomized clinical trial comparing RFA and splenectomy with 5 years of follow-up are reported.

METHODS

Fifty-seven patients with hypersplenism due to liver cirrhosis were assigned randomly (in a 1 : 2 ratio) to splenectomy (19 patients) or RFA (38). The RFA group was subdivided according to the percentage of the spleen ablated: less than 50 per cent (9 patients), 50-70 per cent (18) or over 70 per cent (11). Routine blood tests were performed before and after operation, and total spleen volume and ablated volume were measured by contrast-enhanced computed tomography. The primary endpoint of the trial was recurrence of hypersplenism, assessed as platelet and white cell counts, at 5 years after surgery.

RESULTS

White cell and platelet counts increased rapidly after intervention in both groups. By 36 months after operation peripheral platelet and white cell counts had decreased significantly in the RFA group compared with the splenectomy group, and declined to baseline levels by 48 months. Hypersplenism recurred after 6 months in patients with less than 50 per cent of the spleen ablated. Blood cell count in the splenectomy group and in patients with more than 50 per cent of the spleen ablated decreased with time after operation, but to levels that remained significantly higher than those before operation (P < 0·050). Splenic volume reached its nadir 12 months after RFA and then increased with time.

CONCLUSION

Splenic RFA represents an attractive alternative treatment for hypersplenism induced by liver cirrhosis, particularly when more than 50 per cent of the spleen is ablated.

Electromagnetic thermoablation to treat thrombocytopenia in cirrhotic and hypersplenic rats

BACKGROUND AND AIM

Thrombocytopenia due to hypersplenism is usually a serious condition in cirrhotic patients who have undergone invasive procedures. We designed a new treatment method using a high-frequency alternating electromagnetic force to treat the disease condition in a rat model.

METHODS

Sprague-Dawley rats were given thioacetamide in drinking water and injected with methylcellulose intraperitoneally to create a cirrhotic hypersplenism model. Spleen volume was determined using the Carlson method. The Control Group consisted of 14 rats, 15 weeks old, that were used to determine the normal platelet count and normal spleen size. Experimental Group I, consisting of 15 rats, received electromagnetic thermoablation of their spleens, after which the spleen was returned to the abdomen. Group II consisted of 13 rats, receiving the same electromagnetic thermoablation as Group I, but the ablated portion was removed. Group III consisted of 14 rats receiving total splenectomies.

RESULTS

Cirrhotic hypersplenism was confirmed during laparotomy and pathological examination. Spleen volume enlarged from 1513 +/- 375 mm(3) (Control Group) to 7943 +/- 2822 mm(3) (experimental groups). Platelet counts increased from 0.35 +/- 0.21 x 10(6)/mm(3) to 0.87 +/- 0.24 x 10(6)/mm(3) for Group I, from 0.52 +/- 0.23 x 10(6)/mm(3) to 1.10 +/- 0.20 x 10(6)/mm(3) for Group II, and from 0.47 +/- 0.23 x 10(6)/mm(3) to 1.18 +/- 0.26 x 10(6)/mm(3) for Group III. No rats died due to the treatment in any of the experimental groups.

CONCLUSIONS

Our animal model performed successfully and our proposed electromagnetic thermotherapy effectively treated thrombocytopenia due to cirrhotic hypersplenism.

Radiofrequency ablation of the spleen in patients with thalassemia intermedia: a pilot study

OBJECTIVE

We investigated the efficacy and safety of radiofrequency ablation on the hematologic parameters in patients with thalassemia intermedia (TI).

MATERIALS AND METHODS

Radiofrequency ablation of the spleen was performed in 15 children with TI under general anesthesia using a cool-tip radiofrequency probe. These patients were regarded as the radiofrequency ablation group. Nine patients with TI who underwent partial splenectomy during the past 3 years and another 14 patients with TI who underwent total splenectomy were also enrolled in this study as the first and second control groups (CG1 and CG2).

RESULTS

In the radiofrequency ablation group, two (13%) patients showed a significant increase in the mean hemoglobin level compared with the year before (1.5 and 1.8 g/dL). In addition, three (20%) other patients became transfusion-free in the year after radiofrequency ablation. In CG1, one (11%) patient showed a significant increase in hemoglobin the year after partial splenectomy, and another two (22%) patients became transfusion-free. In CG2, six (43%) patients revealed a significant increase in hemoglobin in the year after total splenectomy, and another four (29%) revealed a significant decrease in the need for transfusions. The mean increase in hemoglobin and platelet count was more significant in CG2 than in the radiofrequency ablation group and CG1. The mean hospital stay was significantly shorter in the radiofrequency ablation group (1.7 days vs 7.5 and 8.2 days in CG1 and CG2, respectively).

CONCLUSION

We believe that radiofrequency ablation of the spleen can be a safe procedure in patients with TI and is at least as effective as partial splenectomy, having only minor self-limiting complications.

Hypersplenism induced by splenic vein ligation

Warm autoimmune hemolytic anemia (AIHA) is a rare clinical entity. It is usually caused by an IgG autoantibody directed against the red blood cell membrane that causes extravascular hemolysis predominantly in the spleen. As a result, disease states or procedures that result in hypersplenism would be expected to increase red cell destruction in patients with an underlying warm AIHA. We present the case of a patient with a previously undiagnosed warm AIHA, who developed worsening hemolysis after undergoing splenic vein ligation during a pancreaticoduodenectomy to remove a neuroendocrine tumor.

Two-year follow-up of splenic radiofrequency ablation in patients with cirrhotic hypersplenism: does increased hepatic arterial flow induce liver regeneration?

BACKGROUND

Hepatocyte hypoxia may be a mechanism determining abnormal tissue oxygenation and dysfunction of the cirrhotic liver. Since the introduction of radiofrequency ablation (RFA) for patients with cirrhotic hypersplenism, we observed a phenomenon of visible hepatic regeneration. This study aims to investigate the potential mechanism of RFA-induced liver regeneration, and the 2-year outcomes of splenic RFA.

METHODS

Forty patients who underwent splenic RFA for cirrhotic hypersplenism were followed for 24 months. Before and after RFA procedures, portal hemodynamics and liver and spleen volumes were measured by Doppler ultrasonography and computed tomography volumetry. Liver function tests and blood counts were also determined.

RESULTS

The splenic and portal venous flows decreased, but hepatic arterial flow (HAF) increased dramatically after the RFA procedure. Liver volumes at 3 month post-RFA increased compared to the baseline volumes (872 +/- 107 vs. 821 +/- 99 cm(3), P = .031). A correlation was found between maximum absolute values of liver volumes (triangle upliver volumes) and that of HAF (triangle upHAF) in Child-Pugh class A/B patients (r = 0.60; P < .001). Leukocyte and platelet counts, as well as liver function, improved substantially during the 2-year follow-up. Patients with > or = 40% of spleen volume ablated had better improvement of thrombocytopenia. No death or severe complications occurred.

CONCLUSIONS

RFA for cirrhotic hypersplenism is safe and efficacious. The increase in HAF as a result of splenic RFA may improve liver function and induce liver regeneration in cirrhotics, but further studies are necessary to clarify the underlying mechanisms.

Changes in peripheral lymphocyte subsets in patients after partial microwave ablation of the spleen for secondary splenomegaly and hypersplenism: a preliminary study

PURPOSE

Microwave ablation therapy for secondary splenomegaly and hypersplenism has been shown to be effective from pre-clinical animal models and clinical investigations. This study was performed to determine its effects on the status of peripheral lymphocyte subsets in patients receiving microwave ablation of the spleen.

MATERIALS AND METHODS

Ten patients with secondary splenomegaly and hypersplenism received microwave ablation of the spleen during laparoscopy or percutaneously under ultrasound guidance. The percentage peripheral blood T cells, B lymphocytes and NK cells were measured using flow cytometry before and on days 1, 3 and 7 after therapy, as well as 1 and 3 months afterwards.

RESULTS

Percentages of CD3(+) and CD4(+) cells increased rapidly 1 month after therapy. There was no significant change in CD8(+), CD4(+)/CD8(+) or NK cells of the pre- and post-therapy levels and B lymphocytes increased significantly after therapy. In patients with an ablation volume (AV) less than 20% (group A), T cells increased 1 month after ablation but decreased 3 months after ablation. B lymphocytes increased significantly after surgery. Levels of NK cells were lower than that before therapy on each testing. In patients with 20-40% AV (group B), levels of T cells, B lymphocytes and NK cells showed an increase. Levels of CD4(+) cells were significantly higher in group B than in group A, 3 months after therapy.

CONCLUSIONS

Microwave ablation therapy for splenomegaly and hypersplenism appears to have a favourable effect on peripheral lymphocyte subsets. A relationship may exist between the ablation volume and the level of peripheral lymphocyte subsets.

CT-guided percutaneous radiofrequency ablation of spleen: a preliminary study

OBJECTIVE

The objective of our study was to evaluate the technical feasibility, safety, and changes of platelet counts of CT-guided percutaneous radiofrequency ablation of normal spleen in a porcine model.

CONCLUSION

It is feasible and safe to perform CT-guided percutaneous radiofrequency ablation of the spleen in a pig. Although further study is still required in clinical applications, this method can be a minimally invasive and effective therapeutic technique in patients with hypersplenism.

A case of splenic abscess after radiofrequency ablation

Radiofrequency ablation (RFA) is an innovative technique used primarily for the palliative treatment of unresectable liver tumors. Its therapeutic indications however, have been expanded and now include various other organs and diseases. There is a paucity of data regarding technical details and complications of the use of RFA in the spleen. We report a case of partial splenectomy using radiofrequency ablation for splenic hydatid disease, complicated by an abscess formation.

Splenic arterial interventions: anatomy, indications, technical considerations, and potential complications

Splenic arterial interventions are increasingly performed to treat various clinical conditions, including abdominal trauma, hypersplenism, splenic arterial aneurysm, portal hypertension, and splenic neoplasm. When clinically appropriate, these procedures may provide an alternative to open surgery. They may help to salvage splenic function in patients with posttraumatic injuries or hypersplenism and to improve hematologic parameters in those who otherwise would be unable to undergo high-dose chemotherapy or immunosuppressive therapy. Splenic arterial interventions also may be performed to exclude splenic artery aneurysms from the parent vessel lumen and prevent aneurysm rupture; to reduce portal pressure and prevent sequelae in patients with portal hypertension; to treat splenic artery steal syndrome and improve liver perfusion in liver transplant recipients; and to administer targeted treatment to areas of neoplastic disease in the splenic parenchyma. As the use of splenic arterial interventions increases in interventional radiology practice, clinicians must be familiar with the splenic vascular anatomy, the indications and contraindications for performing interventional procedures, the technical considerations involved, and the potential use of other interventional procedures, such as radiofrequency ablation, in combination with splenic arterial interventions. Familiarity with the complications that can result from these interventional procedures, including abscess formation and pancreatitis, also is important.

Radiofrequency ablation for hypersplenism in patients with liver cirrhosis: a pilot study

Radiofrequency ablation is a relatively new technique used for local ablation of unresectable tumors. We investigated the feasibility and efficacy of radiofrequency ablation for hypersplenism and its effect on liver function in patients with liver cirrhosis and portal hypertension. Nine consecutive patients with hypersplenism due to cirrhotic portal hypertension underwent radiofrequency ablation in enlarged spleens. The ablation was performed either intraoperatively or percutaneously. Patients are followed up for over 12 months. After treatment, between 20% and 43% of spleen volume was ablated, and spleen volume increased by 4%-10.2%. White blood cell count, platelet count, liver function, and hepatic artery blood flow showed significant improvement after 1-year follow-up. Splenic vein and portal vein blood flow were significantly reduced. Only minor complications including hydrothorax (three of nine patients) and mild abdominal pain (four of nine patients) were observed. No mortality or other morbidity occurred. Radiofrequency ablation is a safe, effective, and minimally invasive approach for the management of splenomegaly and hypersplenism in patients with liver cirrhosis and portal hypertension. Increased hepatic artery blood flow may be responsible for sustained improvement of liver condition. Radiofrequency ablation may be used as a bridging therapy for cirrhotic patients waiting for liver transplantation.

Evaluation of a canine model of secondary hypersplenism induced by splenic vein ligation

AIM

To introduce and evaluate a canine model of secondary hypersplenism induced by splenic vein ligation.

METHODS

Eighteen healthy mongrel dogs were randomly divided into three groups. The first group (n = 4) underwent laparotomy, the second (n = 10) and third groups (n = 4) underwent laparotomy plus ligation of splenic vein and its collateral branches to induce congestive splenomegaly. At the end of the third week, splenectomy was performed in the third group. The blood cell counts for peripheral venous blood were determined weekly, and the radiographic and histopathological changes of spleen also obtained regularly.

RESULTS

The erythrocyte and platelet counts decreased in the first week, and were significantly lowered (erythrocyte count of (6.8 ± 1.2)×10¹²/L in control vs (5.1± 0.7)×10¹²/L in second group, P<0.01; and platelet counts of (398 ± 58)×10⁹/L vs (230 ± 86)109/L, P<0.05 respectively) at the end of 3rd week after splenic vein ligation thereafter sustained. The splenomegaly, erythrocytopenia and thrombocytopenia had remained over 9 weeks. No significant changes of the leukocyte counts were observed after splenic vein ligation throughout the experiment (P>0.05). The abnormal status of erythrocytopenia and thrombocytopenia was ameliolated by splenectomy, and the erythrocyte and platelet counts were similarly to the levels of the control group in the second week after splenectomy. After the end of 3rd week after splenic vein ligation, the splenic histopathological changes conformed to the changes of chronic congestive splenomagely.

CONCLUSION

The method of splenic vein ligation to induce experimental secondary hypersplenism is simple and effective. This is a relative ideal model for surgical or interventional therapy on hypersplenism.