Risk Factors Associated with Clinical Failure of Uterine Artery Embolization for Postpartum Hemorrhage.

PURPOSE: To identify risk factors for clinical failure of uterine artery embolization (UAE) for postpartum hemorrhage (PPH), with particular attention to the uterine artery diameter. MATERIALS AND METHODS: This retrospective study included 47 patients who underwent UAE for PPH between January 1, 2010, and January 31, 2021. Technical success was defined as the completion of embolization of the arteries thought to be the cause of the bleeding. Clinical success was defined as no recurrent bleeding or need for additional therapeutic interventions. Univariate and multivariate analyses were performed to examine the risk factors associated with clinical failure of UAE. RESULTS: Of the 47 patients, 6 had recurrent bleeding. Of the 6 patients, 4 underwent hysterectomy, and 2 underwent repeat embolization. The clinical success rate was 87.2% (41/47), with no major adverse events such as uterine infarction or death. In univariate analysis, there were slight differences in multiparity (P = .115) and placental abruption (P = .128) and a significant difference in the findings of a narrow uterine artery on digital subtraction angiography (DSA) (P = .005). In multivariate analysis, only a narrow uterine artery on DSA was a significant factor (odds ratio, 18.5; 95% confidence interval, 2.5-134.8; P = .004). CONCLUSIONS: A narrow uterine artery on DSA was a risk factor for clinically unsuccessful UAE for PPH. It may be prudent to conclude the procedure only after it is ensured that vasospasm has been relieved.

Percutaneous sclerotherapy with OK-432 for lymphocele after pelvic or para-aortic lymphadenectomy: preliminary results.

BACKGROUND: Lymphoceles can result from disruption of lymphatic vessels after surgical procedures in areas with extensive lymphatic networks. Percutaneous catheter drainage with sclerotherapy can be performed for the treatment of lymphoceles. OK-432 has been used to treat benign cysts, such as lymphangioma and ranula. Therefore, we aimed to report the efficacy and safety of sclerotherapy using OK-432 for postoperative lymphoceles. This study retrospectively analyzed 16 patients who underwent sclerotherapy using OK-432 for postoperative pelvic and para-aortic lymphoceles between April 1, 2012, and March 31, 2020. All the patients underwent percutaneous drainage before sclerotherapy. The indications for sclerotherapy were persistent drainage tube output of greater than 50 mL per day and recurrent lymphoceles after percutaneous drainage. If less than 20 mL per day was drained after sclerotherapy, the tube was removed. When the drainage tube output did not decrease to less than 20 mL per day after the first sclerotherapy, the second sclerotherapy was performed 1 week later. Technical success was defined as the completion of drainage and sclerotherapy procedures. Clinical success was defined as the resolution of the patient's symptoms resulting from lymphoceles without surgical intervention. This study also evaluated the complications of sclerotherapy and their progress after sclerotherapy. RESULTS: The mean initial lymphocele size and drainage duration after sclerotherapy were 616 mL and 7.1 days, respectively. The technical success rate and clinical success rate were 100% and 93%, respectively. Thirteen patients were treated by one-session sclerotherapy and three patients were treated by two-session sclerotherapy. Minor complications (fever) were observed in eight patients (50%). A major complication (small bowel fistula) was observed in one patient (7%). No recurrence of lymphoceles was observed during the mean follow-up period of 17 months. CONCLUSION: Sclerotherapy with OK-432 is an effective therapeutic method for postoperative lymphoceles. Although most complications are minor, a small bowel fistula was observed in one patient.

PIK3CA mutation correlates with mTOR pathway expression but not clinical and pathological features in Fibfibroipose vascular anomaly (FAVA).

BACKGROUND: Fibro-adipose vascular anomaly (FAVA) is a rare and new entity of vascular anomaly. Activating mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene were identified at a frequency of 62.5% in FAVA cases. The PIK3CA mutations excessively activate mammalian target of rapamycin (mTOR) pathway, which promotes angiogenesis and lymphangiogenesis, implying that PIK3CA mutations may act as drivers of FAVAs. This study investigated the correlations between PIK3CA mutational status, clinicopathological features and immunohistochemical expression of the mTOR pathway in a series of FAVA. METHODS: We retrospectively evaluated the clinical and pathological findings of four FAVA cases. We performed next-generation sequencing (NGS) with a custom panel of genes associated with the mTOR pathway and genes responsible for other vascular anomalies; followed by direct sequencing and immunohistochemical analysis of the mTOR pathway. RESULTS: Two PIK3CA-mutation cases and two PIK3CA-wild-type (wt) cases exhibited similar typical clinical features of FAVA. Histological analysis revealed venous malformation, lymphatic malformation, nerves containing enlarged abnormal vessels and fibrofatty tissue were observed regardless of PIK3CA mutational status. In contrast to clinical and histological findings, the immunohistochemical expression of activated AKT and mTOR that are upstream of the mTOR pathway was detected in abnormal vessels of PIK3CA-mutation cases but not in those of PIK3CA-wt cases. However, activated eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1), both of which are downstream effectors of the mTOR pathway, were expressed in abnormal vessels of both PIK3CA-mutation and PIK3CA-wt cases. Furthermore, targeting NGS did not find any common genetic mutations involved in the mTOR pathway among PIK3CA-wt cases. CONCLUSIONS: There was no significant association between the presence of PIK3CA mutations and the clinicopathological features of FAVA, suggesting that the PIK3CA gene is not necessarily involved in the onset of FAVA. FAVAs lacking PIK3CA mutations may be caused by other gene mutations that activate 4EBP1 and S6K1.

Venous Sac and Feeding Artery Embolization versus Feeding Artery Embolization Alone for Treating Pulmonary Arteriovenous Malformations: Draining Vein Size Outcomes.

PURPOSE: To investigate and compare venous sac and feeding artery embolization (VFE) with feeding artery embolization (FAE) alone for treatment of pulmonary arteriovenous malformations (PAVMs), based on difference in outcomes in decrease of the size of the draining vein. MATERIALS AND METHODS: Twenty-six patients (7 male and 19 female; median age [interquartile range], 58 years [46-65 years]) with 42 simple PAVMs treated with coil embolization between August 2005 and December 2018 were retrospectively evaluated. Twenty PAVMs were treated with FAE early in the study period and compared with 22 PAVMs treated with VFE later in the study period. Follow-up computed tomography images obtained 8-20 months after embolotherapy were used for outcome analysis. Data related to patient demographics; follow-up period; baseline diameters of the feeding artery, venous sac, and draining vein; draining vein diameter after treatment; and decrease in the size of the draining vein, including the number reaching a threshold of 70% decrease, were compared between the 2 groups. RESULTS: The draining vein decreased in size by a median of 46.4% in the FAE group and 66.3% in the VFE group, and the difference between the 2 groups was statistically significant (P = .009). There were no significant differences in the other parameters. CONCLUSIONS: VFE leads to a greater decrease in the size of the draining vein than FAE, suggesting that VFE results in more complete occlusion than FAE for treatment of PAVMs.

Efficacy of prophylactic selective arterial embolization for renal angiomyolipomas: identifying predictors of 50% volume reduction.

BACKGROUND: Transcatheter arterial embolization (TAE) has been widely performed for renal angiomyolipomas (AMLs) as prophylaxis or emergency treatment. On the other hand, mammalian target of rapamycin (mTOR) inhibitors have recently been used for tuberous sclerosis (TSC)-related AMLs, and no comparison between the effectiveness of mTOR inhibitors versus prophylactic selective TAE has yet been performed. Therefore, the purpose of this study was to evaluate the efficacy of TAE for AML tumor volume reduction and predictors of tumor volume decrease over 50%, with reference to the EXIST-2 trial. METHODS: A total of 44 patients who underwent 48 prophylactic embolization procedures for 50 AMLs in a single institution between 2004 and 2018 were included. Indications for TAE of AMLs were tumor size ≥4 cm or aneurysm ≥5 mm in diameter on contrast-enhanced computed tomography (CECT). Microspheres, ethanol, and micro-coils were used as embolic agents. The percentage volume reduction from before TAE to the minimum volume during follow-up after TAE was calculated, and predictors for 50% volume reduction were identified by univariate and multivariate binary logistic regression analyses. RESULTS: The technical success rate was 100% (50 of 50). No severe acute complications related to the procedure were encountered. Tumor volume reduction of ≥50% was observed in 35/50 AMLs. There was a significant difference in the rate of tumor volume reduction of 50% between the presence and absence of an aneurysm ≥5 mm and between tumor diameter ≥ 70 mm and < 70 mm on univariate analysis. On multivariate analysis, tumor diameter < 70 mm was the only independent predictor of significant tumor volume reduction after TAE. CONCLUSION: Prophylactic selective TAE for AMLs has good tumor-reduction effects, especially for AMLs with tumor diameter < 70 mm.

The efficacy of uterine artery embolization with gelatin sponge for retained products of conception with bleeding and future pregnancy outcomes.

BACKGROUND: Retained products of conception (RPOC) with hemorrhage need intervention when RPOC persist and remain symptomatic. The safety and efficacy of uterine artery embolization (UAE) for RPOC using gelatin sponge (GS) alone, and fertility after UAE for RPOC remain unknown. The purpose of this study is to retrospectively investigate the efficacy of UAE for RPOC with bleeding and future pregnancy outcomes. METHODS: Between 2007 and 2016, 14 patients (mean age, 33 years old) diagnosed as RPOC with bleeding received UAE using GS at our institution. Pregnancy outcomes were vaginal delivery (n = 7), miscarriage (n = 4), and termination (n = 3). Four patients received dilation and curettage/evacuation (D&C/E) for treatment of RPOC before bleeding occurred. The mean time interval from the end of pregnancy to bleeding was 28 days. Technical success, clinical success, complications, angiographic features and fertility after UAE were retrospectively assessed. RESULTS: Technical success was achieved in 13 patients (93%) and clinical success was achieved in all 14 patients. No major complications occurred. The angiographic features of RPOC were tortuous feeders with flow into a focal blush of contrast (n = 14). Additional findings were pseudoaneurysm (n = 6), early venous return (n = 4), and extravasation (n = 2). Pseudoaneurysm was observed significantly more often in patients who received D&C/E before UAE compared to those who received conservative treatment alone (P = 0.015). The mean follow-up period was 29 months. Six patients achieved six pregnancies an average of 29 months after UAE. CONCLUSION: UAE using GS may be an effective and safe treatment for RPOC with hemorrhage that can preserve fertility.

Significance of fistulography findings to the healing time of postoperative pancreatic fistula after pancreaticoduodenectomy.

PURPOSE: Pancreatic fistula (PF) is a common and serious complications after pancreaticoduodenectomy (PD). However, few studies have discussed the time required for PF healing in patients with this complication. This study investigates the PF healing time (PF-HT) and its association with findings of postoperative fistulography performed via the drainage tubes. METHODS: The subjects of this study were 35 patients with PF among a total of 144 patients who underwent PD for periampullary diseases in our hospital. PF-HT, which was defined as the duration from the first postoperative fistulography to removal of the drainage tubes, was assessed in the enrolled patients. Fistulography findings were classified into four types based on fluid collection and communication with the jejunal loop. We investigated the factors affecting the PF-HT, including the fistulography findings. RESULTS: The average PF-HT was 22 ± 20 days. Multivariate analysis revealed that the fistulography type was the only independent factor that affected PF-HT significantly. The PF-HT was significantly shorter in patients without fluid collection than in those with fluid collection. Moreover, those patients with fluid collection and a communication had a significantly shorter PF-HT than those without a communication. CONCLUSIONS: We found that fistulography findings were significantly associated with the PF-HT. This suggests that fistulography findings could help to predict the time needed for PF healing.

The Branching Pattern of the Inferior Pancreaticoduodenal Artery in Patients with a Replaced Right Hepatic Artery.

Understanding the anatomy of the inferior pancreaticoduodenal artery (IPDA) is important in patients undergoing pancreaticoduodenectomy, especially in an artery-first approach, resulting in some studies focusing on IPDA anatomy. However, the studies have covered only cases without variation in hepatic arterial anatomy, a common arterial variant, suggesting the necessity of the investigation of IPDA anatomy in cases with the variant. Using images of multidetector row computed tomography, cases with replaced right hepatic artery (rRHA) were picked out among 714 patients undergoing multidetector row computed tomography for determining arteries of the pancreatic head at our institution. IPDA branching pattern was investigated in the rRHA cases. Three-dimensional reconstruction was performed to visually understand the branching pattern in representative cases. rRHA was identified in 139 cases (19.5%); rRHA originating from the superior mesenteric artery (SMA) (type 1; 74.1%), celiac axis (type 2; 18.0%), and others (type 3; 7.9%). IPDA branching pattern was categorized; IPDA originated from SMA (type A), posterior and anterior IPDA originated from rRHA and SMA, respectively (type B), or IPDA originated from rRHA (type C). Of type 1 cases, 69, 23, and 11 cases showed type A, B, and C pattern, respectively. Of type 2 cases, 16 and 9 cases showed type A and B, respectively. All 11 type 3 cases showed type C. IPDA branching pattern was determined in the rRHA cases. This would help identification of rRHA cases where the artery-first approach is technically less feasible at pancreaticoduodenectomy (type 1-B, 1-C, and 2-B).

Distance from Left Renal Vein to Inferior Pancreaticoduodenal Artery: A Landmark for Identifying Inferior Pancreaticoduodenal Artery in Pancreatoduodenectomy.

BACKGROUND/AIM: During pancreatoduodenectomy, early ligation of major afferent arteries to pancreatic head prior to dissection of the corresponding veins may reduce intraoperative bleeding. Inferior pancreaticoduodenal artery (IPDA), one of the major afferent arteries, is difficult to identify. We measured the distance from left renal vein to IPDA based on preoperative multi-detector row computed tomography (MDCT) images for use as a new landmark for IPDA. METHODS: The distance between left renal vein and IPDA was measured in 417 patients using MDCT images. RESULTS: IPDA was identified on MDCT images in 415 out of the 417 patients (99.5%). The root of IPDA was located on cranial side of the root of left renal vein in 88 among the 415 patients (21.2%), and the distance was expressed as negative in these cases. The distance was 6.09 ± 7.46 mm. The distance when IPDA formed a common vessel with first jejunal artery (8.03 ± 6.74 mm; 323 cases, 77.8%) was significantly longer than when IPDA branched directly from superior mesenteric artery (SMA; -0.81 ± 5.74 mm; 62 cases, 15.0%) or posterior and anterior IPDAs branched separately from SMA (-2.04 ± 5.36 mm; 30 cases, 7.2%). CONCLUSIONS: The distance between left renal vein and IPDA can serve as a landmark for IPDA identification.

[Afferent Loop Syndrome after Hepatobiliary and Pancreatic Surgery Successfully Treated with Percutaneous Drainage].

We report 2 cases where afferent loop syndrome after hepatobiliary and pancreatic surgery was successfully treated with percutaneous drainage. Case 1: A 74-year-old man who had undergone pancreaticoduodenectomy for pancreatic cancer presented with cholangitis, obstructive jaundice, and dilatation of the elevated jejunum. These conditions were attributed to obstruction of the elevated jejunum on the anal side due to peritoneal dissemination. Subsequently, percutaneous transhepatic biliary drainage was performed, and the dilated jejunum was drained through the approach route. Case 2: A 71-year-old woman who had undergone left hepatectomy for hilar bile duct cancer presented with peritoneal dissemination. Owing to the dissemination, the elevated jejunum was obstructed, resulting in its dilatation on the oral side. Percutaneous drainage of the dilated jejunum was directly performed. Percutaneous drainage was effective in both the abovementioned cases, and no symptoms related to the obstruction were observed until the death of the patients because of primary cancer. This suggested that percutaneous drainage may be an effective treatment option for afferent loop syndrome after hepatobiliary and pancreatic surgery.

In vivo evaluation of irinotecan-loaded QuadraSphere microspheres for use in chemoembolization of VX2 liver tumors.

PURPOSE: To investigate the pharmacokinetics and chemoembolization efficacy of irinotecan-loaded QuadraSphere microspheres (QSMs) in a rabbit VX2 liver tumor model. MATERIALS AND METHODS: Fourteen rabbits with VX2 liver tumors were divided into two groups. In the irinotecan-loaded QSM group (n = 7), 3 mg of QSMs (30-60 µm) containing 12 mg of irinotecan (0.6 mL; 20 mg/mL) were injected into the left hepatic artery. In the control group (hepatic arterial infusion [HAI] and QSMs; n = 7), 3 mg of QSMs suspended in ioxaglic acid were injected following a bolus injection of 0.6 mL of irinotecan solution (20 mg/mL). Sequential irinotecan, SN-38, and SN-38G concentration changes were measured in plasma within 24 hours and at 1 week and in tissues at 1 week. The VX2 tumor growth rates at 1 and 2 weeks were calculated from computed tomographic images. RESULTS: All rabbits underwent successful embolization. Plasma irinotecan, SN-38, and SN-38G concentrations in the irinotecan-loaded QSM group showed significantly sustained release compared with the control group (P = .01). Compared with the control group, the irinotecan-loaded QSM group had significantly higher irinotecan concentration in liver tumors (P = .03) and a tendency toward higher SN-38 concentration in liver tumors (P = .29). The SN-38G tissue concentrations were below the limits of quantification. The tumor growth rate was significantly lower and the tumor necrosis rate significantly higher in the irinotecan-loaded QSM group (P = .02 and P = .01, respectively). CONCLUSION: Chemoembolization via irinotecan-loaded QSMs more effectively suppresses tumor growth than chemoembolization with unloaded QSMs after HAI. A clinical feasibility study is warranted.

Initial experience with use of hydrogel microcoils in embolization of pulmonary arteriovenous malformations.

The purpose of this study is to describe our initial experience with embolization of pulmonary arteriovenous malformations (PAVMs) using hydrogel microcoils. The technical and radiological outcomes were retrospectively reviewed in seven patients with nine simple-type PAVMs (median feeder size 4 mm, range 3-6 mm) who underwent embolization. Hydrogel microcoils were mainly used, and detachable bare microcoils were combined as needed to occlude the terminal feeding artery just before the sac. Of a total of 43 microcoils, 30 (69.8%) hydrogel microcoils were deployed in eight PAVMs with the median number 3.5 (range 2 to 6) per lesion. All hydrogel microcoils were successfully deployed without microcatheter stuck or malposition. In the remaining one small PAVM, only soft bare microcoils were used, however, resulting in recanalization requiring additional coils in the second session. The venous sac was substantially shrunk in all lesions treated with hydrogel microcoils with the median size reduction rate 95.0% (range 81.8% to 99.0%) during the median follow-up period 10 months (range 6 to 18 months). In conclusion, hydrogel microcoils were safely and effectively applied for occluding PAVMs with relatively small feeders.

Current status of embolic agents for liver tumor embolization.

Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.