Percutaneous ethanol injection therapy (PEIT) has been administered as a safe therapeutic modality for patients with small hepatocellular carcinoma (HCC). Due to the nature of the straight approaching line of a PEIT or radiofrequency ablation needle, penetrating the vessels that are interposed between the dermal insertion point and the nodule is unavoidable. A device with an overcoat needle and coaxial curved PEIT needle was created that facilitated a detour around interposing large vessels in order to avoid unnecessary harmful effects that result from the PEIT procedure. Two cases of HCC located adjacent to a neighboring large vessel were treated with a curved PEIT needle. The curved PEIT needle, which is connected to an outer needle, enabled deviation around the interposing vessels and successful connection with the HCC. Careful use of the curved line of the PEIT needle enabled the safe and successful performance of the PEIT without any requirement for specific training. This hand-assisted technique may be an applicable treatment for small HCC located beneath large vessels as a direct therapeutic method using ultrasound guidance.
Techniques for percutaneous ethanol injection therapy (PEIT) have been widely established to treat hepatocellular carcinoma (HCC) and have once been applied in larger size cancer nodules using a multiple-insertion technique (
A 79-year-old male, exhibiting a HCC that was 2.6 cm in diameter and located in Couinaud’s S4 subsegment (S4), underwent conventional PEIT with a mixture of 5 ml of 99.5% ethanol and 0.6 ml of iodized oil (Lipiodol) in January 2005 (
In January 2005, an additional HCC (size, 1.6×1.6 cm) was identified behind the treated HCC, which was located just beneath a branch of the large left portal vein on the approaching line of the ultrasound image (
A 56-year-old male who was positive for the hepatitis C virus and exhibited liver cirrhosis was referred to the Kagawa University Hospital (Miki-cho, Japan) for the treatment of recurrent HCC. In 2000, the patient was treated with RFA twice for HCCs that were 2.0 and 1.6 cm in diameter, and located in S8 and S7, respectively. An additional HCC, 1.9 cm in diameter, was identified in S7 and treated angiographically using a mixture of Lipiodol and a lipophilic anticancer agent, styrene maleic acid neocarzinostatin (Lipiodol; Yamanouchi Pharmaceutical Co., Ltd., Tokyo, Japan), which was followed by a transcatheter embolization of the tumor (
Prior to performing the procedure, written informed consent was obtained from each patient’s family and the study was approved by the clinal ethics committee of Kagawa University Hospital (Kagawa, Japan). The patients were treated with the same method as follows.
An 18-gauge PEIT needle (20-cm long; Hakko Co., Ltd., Chikuma, Japan), which was manually curved into a fishhook shape, was prepared (
Subsequent to receiving local anesthetic, the coaxially prepared needles were held by the overcoat needle and inserted with ultrasonic guidance into the lateral side of the interposing vessel edge, above the cancer nodule. The curved PEIT needle was extended slowly from the overcoat needle towards the HCC. The quantity of ethanol that was injected by a single shot was 0.5–1.0 ml. A total of 5 ml of 99.5% ethanol was injected in small doses through the curved PEIT needle.
A large portal vein intersected the dermal insertion point of the PEIT needle and the cancer nodule in the two patients. To reinforce the straight structure of the outer needle following insertion of the inner curved PEIT needle, a 16-gauge outer needle was required. As the curved PEIT needle was extended from the overcoat needle into the parenchyma of the liver at the lateral side of a large vessel neighboring the HCC, the needle did not maintain the original curve that was previously visualized. The curved PEIT needle gradually lost its shape and weakened in the liver parenchyma, resulting in the angle of the anticipating approach curve becoming a weak curved line in the fibrotic liver. Therefore, it was required that the inner PEIT needle was fixed as a stronger curve in advance, or that an overcoat needle was inserted nearer to the target than the simulation line. As a result of the curve in the needle, it detoured the large vessel adjacent to the HCC (
Ultrasound-guided percutaneous ablation therapy has developed during the past two decades (
In multivariate analysis, the significant prognostic factors have been determined as local recurrence, and tumor size and number. This indicates that successfully attaining a complete treatment for HCC during the first treatment is significant for improving the prognosis of patients with HCC (
Furthermore, for patients with small HCC, PEIT may produce a survival rate comparable to surgical resection (
PEIT-associated adverse effects are not as serious compared with those of RFA therapies, however, studies regarding vascular or bile duct damage, such as hepatic infarction (
In conclusion, the present study reports two cases of HCC treated with a curved PEIT needle. For the purpose of achieving PEIT safely, a novel PEIT needle was created with an overcoat needle and a coaxial curved PEIT needle for the treatment of small HCC adjacent to an intrahepatic large vessel. In cases of patients with small HCC, which is difficult to approach with a conventional strait PEIT needle, the curved PEIT needle presented in the current study may be effective in avoiding unnecessary adverse effects
Image findings for patient 1. (A) Ultrasonograms captured by right intercostal scanning prior to therapy. A large portal vein (PV) intersects the puncture point and the nodule (arrow). A curved percutaneous ethanol injection therapy (PEIT) needle was used to conduct the right subcostal scanning during therapy. (B) The needle tract of an overcoat needle is observed at the left side of the right PV. (C) A small contrast enhanced tumor (1.6×1.6 cm) is located in S4 in the arterial phase of an abdominal, dynamic computed tomography image in patient 1 prior to therapy I (arrow). (D) A white colored nodule on the subcapsular region of the liver demonstrates the remaining iodized oil (Lipiodol) that accumulated during the previous PEIT (with a mixture of ethanol and Lipiodol) in 2005. Subsequent to the therapy, the tumor evolved into a low-density area without contrast enhancement (arrow).
Image findings for patient 2. (A) Ultrasonograms captured by right intercostal scanning prior to therapy. A right portal vein (PV) intersects the puncture point and a low-echoic nodule prior to therapy (arrow). (B) A needle tract of an overcoat needle and an extended curved percutaneous ethanol injection therapy (PEIT) needle from the overcoat needle are observed at the right side of the right PV. A curved PEIT needle deviates around the vessel to the cancer nodule and is inserted in the right side of the tumor (arrow). (C) Immediately following the ethanol injection, the tumor area undergoes a hyperechoic change (arrow). (D) A small enhanced nodule (1.3×1.3 cm) is located in S7 in the arterial phase of an abdominal dynamic computed tomography image prior to therapy I (arrow). (E) Arterial phase image of the abdominal dynamic magnetic resonance imaging scan that was obtained subsequent to the therapy using a curved PEIT needle. The treated area evolved into a low-intensity area following therapy (arrow).
A curved percutaneous ethanol injection therapy (PEIT) needle that is connected to a syringe via an extension tube, is coaxially prepared in an overcoat needle. Note that the head of the PEIT needle is curved in a fishhook shape.