Interventional Radiology in Management of Postoperative Chylous Ascites

Abstract

Postoperative chylous ascites is a rare condition that can be caused by abdominal and pelvic surgery. The mortality rate associated with untreated postoperative lymphorrhea is as high as 50%. Conservative management is the primary treatment, and most patients improve. However, some patients continue to exhibit high-volume chylous ascites and need invasive intervention. Many surgical series have shown that the outcomes of patients with chylous ascites were unfavorable. Therefore, the need for minimally invasive interventional radiology procedures, such as intranodal lymphangiography, thoracic duct, lymphatic pseudoaneurysm, lymph node, hepatic lymphatic embolization, and peritoneovenous shunting, is increasing. This review describes the anatomy, physics, and diagnosis related to interventional radiology for postoperative chylous ascites as well as interventional radiology treatment options and strategies for this condition referring to recent literature.

Introduction

The lymphatic system is essential for the transport of lymphatic fluid from the peripheral lymph vessels into the cisterna chyli (CC) and thoracic duct (TD) to the central bloodstream. Lymph is composed of fat, protein, plasma proteins, and immunologically active cells. Lipid-containing lymphatic fluid which is absorbed in the small intestine is defined as chyle. Chylous ascites (CA) is a condition in which chyle leakage into the peritoneal cavity accumulates, it can be caused by a variety of etiologies.

Various classifications of CA have been reported, such as cirrhotic or non-cirrhotic, traumatic or non-traumatic, and more [1, 2]. According to Allami's classification, CA can be classified as either congenital or acquired. Postoperative CA is categorized as acquired; this category also includes inflammatory, traumatic, neoplastic, cirrhotic, and cardiogenic CA [1, 3]. Although exact data do not exist, the prevalence of postoperative CA is believed to have increased because of the prolonged survival of patients with cancer and more aggressive surgical interventions [2, 4].

Postoperative CA is a complication that can occur after abdominal or pelvic surgery, particularly after extensive abdominal surgical procedures for cancer therapy [5]. Injury of the lymphatic duct causes lipid-rich lymph to collect in the peritoneal cavity, leading not only to ascites, but to dehydration, electrolyte imbalance, malnutrition, and immunosuppression; thus, the loss of chyle may become life-threatening. Some reports have shown that chylous leaks may significantly contribute to morbidity and mortality, with reported mortality rates for CA as high as 40 to 70%, depending on the patient's condition [6]. The mortality rate of untreated postoperative lymphorrhea is as high as 50%, particularly for high-output postoperative lymphorrhea in the thorax and abdomen [7].

A recent review paper reported the incidence of CA after oncologic resection of retroperitoneal lymph nodes was as high as 11% [1].

However, CA was found to occur after surgical procedures other than retroperitoneal operation, such as retroperitoneal lymphadenectomy and maneuvers of the aorta or vena cava, as well as after abdominal surgeries for non-oncological operation, such as catheter placement for peritoneal dialysis [8].

Therefore, postoperative CA may occur in many fields of medical care and many review papers have been reported in each field with differing opinions. Hence, there is no sufficient evidence or consensus regarding the treatment of postoperative CA. Many surgical series have shown that patients with CA have increased morbidity, reduced survival, and prolonged hospital stays [9]. On the other hand, minimally invasive lymphatic procedures such as intranodal lymphangiography or lymphatic embolization are rapidly developing and increasing, mainly in interventional radiology (IR) [10].

This review refers to recent reports in the literature and describes the anatomy, physics, and diagnosis related to IR for postoperative CA, as well as IR treatment options and strategies for this condition.

Anatomy and Physics Related to IR of CA

When considering retrograde cannulation into the TD, morphological information is important. The TD typically extends from the CC to the left jugulovenous angle. It drains upwards of 75% of lymphatic fluid throughout the body and carries 1 to 2 L of lymphatic fluid/day [11]. There are many morphological variations, and it is estimated that the typical course of the TD is present in only 40 to 60% of patients. Several variations in the terminal TD have also been reported. The TD most commonly terminates in the internal jugular vein (54.05%), jugular venous angle (25.79%), and subclavian vein (8.16%) [12]. Typical single-terminal TD was reported in 72% of cases in human subjects. Other types of terminal TD include multiple tributaries with a common single trunk or multiple trunks [13]. The thoracic TD also has variations such as duplication or plexiform configuration. The TD contains multiple bicuspid valves along the duct. These valves may be situated as far as 2 cm from the termination of the duct [3]. At the termination of the duct, the TD penetrates the vein wall obliquely, forming a valve-like structure that prevents backflow of venous blood; therefore, angiography of the subclavian vein can be difficult, making it challenging to obtain contrast images of the TD [14]. The presence of these valves also makes wire advancement in a retrograde approach more difficult [9].

Lympho-venous anastomosis is present at various sites and functions with increased pressure in the lymphatics. Anastomosis has been reported within the TD as well as the azygos vein, renal vein, inferior vena cava (IVC), hepatic vein, and adrenal vein. The lymphatic vessels normally show pulsatile pressures of up to 25 mmHg. It is thought that lymph-venous anastomosis is nonfunctional under normal pressure; however, lymph-venous anastomosis functions when intra-lymphatic pressure increases [3]. Therefore, lympho-venous flow can be preserved after downstream embolization such as TD embolization (TDE).

The CC has also many variations in configuration, size, and position. The majority of CC are positioned at the level of L2 and sit to the right of the midline. The CC size varies from 2 to 32 mm in width and 13 to 80 mm in length, and the majority have a tubular configuration [15, 16]. With regard to puncture and antegrade cannulation with a micro-catheter, thin or plexiform-shaped CC is difficult to treat. The CC has several afferent tributaries. It was reported that the efferent collector of the superior mesenteric lymph nodes (one or multiple) form the gastrointestinal trunk either by themselves or by uniting with the gastric, hepatic, and pancreaticosplenic trunk, which discharges either into the CC or into the left lumbar trunk [17]. A recent anatomical report has shown that the pattern of intestinal trunk discharges into the left lumber was found in 45 out of 100 human cadavers investigated (Fig. 1) [16].

Figure 1.

Anatomic variation of the CC described by Loukass et al. [16] Type I; CC was formed by the union of the left LT and the IT. Type II; CC was formed where the IT opened into the TD and the right and left LT, retroaortic nodes and branches from the intercostal lymphatics joined in a variable manner. Type III; CC was formed by the junction of the right LT and IT. Type IV; could not classified.

CC: cisterna chyli; IT: intestinal trunk; LT: lumber trunk

Diagnosis

Diagnosis of postoperative CA is achieved by visual inspection; a placed drain or punctured output fluid will have a creamy appearance after the surgical procedure. However, a fluid laboratory study is useful to confirm the diagnosis as chylous fluid output if CA appeared well after the operation or serous ascites were formed. A triglyceride concentration above 200 mg/dl supports the diagnosis of CA, while a level less than 50 mg/dl excludes it [8].

Imaging Diagnosis

The most important purpose of imaging modality is the identification of the chylous leak point and pointing to the optimal treatment strategy. Generally, lymphatic scintigraphy is used for this purpose. CT and MRI are supplemental validation modalities for determining the distribution of ascites or morphology of the CC and TD.

Dynamic contrast MR lymphangiography (DCMRL) is a recently developed technique that provides an alternative to lymphatic scintigraphy or conventional lymphangiography due to its detailed spatial resolution with lymphatic flow information and non-invasive nature [18].

Lymphoscintigraphy

Lymphoscintigraphy is a nuclear medicine technique that uses a ⁹⁹Tc antimony sulfide colloid along with dextran or human albumin [1]. After intradermal injection of a radiotracer, a whole body scan is performed. This technique is useful for detecting abnormal retroperitoneal nodes, leakage, fistulization, and patency of the TD [8]. However, lymphatic scintigraphy is often limited by poor resolution when attempting to detect specific localization of a leak [6].

MRI

It has been reported that non-contrast MRL using the magnetic resonance cholangio pancreatography (MRCP) sequence applied to the TD is useful for evaluating its configuration. Okuda et al. [19] investigated 78 patients who had no chylous leak and reported 94% visualization rate of the TD was achieved using bilateral subclavian compression prior to the MRI scan and respiratory gating [19].

Erden et al. [20] reported that in a study of 125 patients without a chylous leak, using T2 weighted MRL achieved visualization of 96% of CC and the abdominal confluence of lymphatic trunks. The intestinal trunk was visible in 13.6% of patients [20]. However, non-contrast MRL can provide only anatomical information; therefore, it is difficult to evaluate the lymphatic flow and leak point when it is indicated for postoperative CA.

DCMRL was developed in recent decades and plays an important role in the diagnosis of non-traumatic lymphatic diseases such as lymphatic malformation [21]. This procedure can be adapted for postoperative lymphorrhea due to anatomical and lymphatic flow information [9, 22]. Kim et al. [23] investigated six patients with postoperative chylothorax, and 66% (4/6) of the cases showed chylous leaks. However, Benjamin et al. [24] insisted that MRL was not indicated for postoperative chylothorax. Regarding CA, as with lymphatic scintigraphy, lymphatic flow outside the tract, such as hepatic lymphatic flow or mesenteric lymphatic flow, cannot be visualized. To compensate for this, challenging techniques such as intra-mesenteric DCMRL and intrahepatic DCMRL have been reported with success, suggesting feasibility and safety [25, 26]. However, using non-contrast and DCMRL for CA has only been reported in case reports, with no reports indicating the probability of depicting leaks.

Therapeutic Strategy

Treatment of chylous leak requires a stepwise approach, starting from conservative management including a multidisciplinary treatment approach, such as decreasing the production of chyle, replacing fluid and electrolytes, and maintaining nutrition status. When conservative management fails, an invasive procedure should be chosen. In all cases, careful attention to the patient's nutrition and immune status should be taken. Monitoring the amount of chylous leaks is mandatory, and peritoneal drainage should be placed immediately after the diagnosis of CA. Steven et al. [27] reviewed 550 patients from numerous retrospective case series, 72% of whom had chyle leaks that healed without surgical intervention.

However, there is no consensus regarding the duration of conservative treatment and the combination of treatments. Generally, the leakage volume per day is classified into high and low volumes with 500 mL/day as the boundary.

Ng et al. [28] recommended that surgical intervention should be considered in patients with a high-volume chylous leak for >14 days. However, other papers have recommended that patients with a continuous leak where volume does not decrease > 1 week, as well as patients with a low output leak for >14 days, should be considered for invasive treatment [6]. Sommer et al. [29] reported in a systematic review that the intervals between “preceding surgery and conventional lymphangiography (CL)” and between “CL and percutaneous IR” were 2-330 and 0-5 days respectively, including patients who underwent lipiodol-based lymphangiography with subsequent percutaneous lymphatic intervention for postoperative lymphorrhea. For postoperative CA only, the intervals between “preceding surgery and CL” and “CL and percutaneous IR” were 5-330 and 0 days respectively [30]. At our institution, scintigraphy is performed when the patient continues to have high-output CA after 7 days of conservative treatment or without showing a decrease in low output after 14 days, and a radiological intervention is scheduled (Fig. 2).

Figure 2.

Treatment algorithm for postoperative chylous ascites.

There is no well-defined consensus on treatment strategy for CA after conservative treatment has failed; each therapy is only described in case reports or a small number of retrospective studies, and even review papers are not consistent. Our IR treatment strategy for postoperative CA is shown in Fig. 3. We start with inguinal intranodal lipiodol lymphangiography, diagnose the leak point by referring to scintigraphy, and then adopt the following treatment option.

Figure 3.

IR algorithm for postoperative chylous ascites.

*Leak points were presumed to be the intestinal trunk, branches near the cisterna chyli, or hepatic lymphatic ducts.

IR: Interventional radiology; TD: thoracic duct

IR Options for Postoperative CA

Lipiodol lymphangiography

Lymphangiography is the most popular procedure for CA treatment as it is a minimally invasive diagnostic tool. In the past, lymphangiography was performed by cutting down the dorsum of the foot to expose the lymphatic vessels and puncturing them with a needle; however, this method is very time-consuming, technically difficult, and invasive, rendering this procedure obsolete.

Intranodal lymphangiography is an innovative novel lymphatic intervention − initially described in 2011, it provides a preferred alternative for pedal lymphangiography, as it is less technically challenging with a shorter procedure time [31]. Under ultrasound guidance, a fine needle is placed in the inguinal lymph node at the junction between the hilum and cortex. Lipiodol is then injected slowly to allow the contrast agent to move up the pelvic and retroperitoneal lymphatic chain to the CC and reach the TD.

Lymphangiography has been shown to have a therapeutic effect on chylous leak, probably due to its embolic or inflammatory effect on the lymphatic vessels [9].

The therapeutic effect of lymphangiography is volume-dependent, and its efficacy is higher in patients with low-output chylous leaks. A previous report has shown that its efficacy was 70% on low-output patients and 35% on high-output (>500 mL/day) patients, including 43 patients with postoperative chylothorax, CA, lymphocele, or lymphatic fistulas [32]. The efficacy of therapeutic lymphangiography for only postoperative CA remains unclear.

The most common finding of lymphangiography is extravasation due to lymphatic leaks. However, a recent report has shown a detection rate of 55% for leakage sites in patients with CA, and this rate was lower than that of chylothorax [2]. Lack of leak visualization may be due to a small intestinal, or hepato-enteral lymphatic leak [30].

Dolan et al. [33] reported complications after lipiodol lymphangiography in 166 of 522 patients (31.8%), including fever (18.6%), nausea/vomiting (4.4%), pain (3.3%), and respiratory signs/symptoms (1.3%). Potentially severe complications include a spectrum of pulmonary complications as well as cerebral and visceral oil embolization injuries [34]. Serious respiratory complications, including pulmonary infarction (0.25%), lipid pneumonia (0.04%), pulmonary edema (0.03%), and hemoptysis (0.03%), have been reported [35]. Extremely rare respiratory complications, such as acute respiratory distress syndrome which developed into pulmonary fibrosis requiring domiciliary oxygen therapy, have been reported; additionally, an allergic inflammatory reaction to lipiodol has been postulated, with the author of the report suggesting that early steroid administration may prevent lung fibrosis [36].

Overdose injection of more than 20 mL increases the risk of embolic complications. A review in the 1960s, long before intranodal lymphangiography was developed, investigated 522 lymphangiograms stratified by volume of administered lipiodol showed that injections of less than 18 mL had a 13% risk, between 18 and 20 mL had a 24% risk, and more than 20 mL had a 48% risk of complication [34]. It is reported that most lymphangiography procedures can be performed with 15 mL of lipiodol or less, although prescribing information stated 20 mL as the maximum lipiodol dose [34]. A systematic review by Sommer et al. [37] stated a maximum dose of 15 ml for lipiodol in intranodal lymphangiography based on data from several small case series. In the dose-proportional pedal lymphangiography complication rate study, the 15 ml for intranodal lymphangiography figure seems reasonable, as the risk of complications increased with doses above 18 ml [34, 37].

No scientific evidence or consensus has been reached regarding children; however, several papers state 0.2 ml/kg as the maximum dose, and prescribing information states 0.25 ml/kg [31, 38].

Moreover, the risk-benefit ratio of lipiodol lymphangiography should be considered, and other modalities such as MRL should be chosen as alternative diagnostic tools for patients with contraindications to lipiodol lymphangiography, such as right-to-left shunt and known pulmonary disease [39].

TDE

TD injury after abdominal surgery is unlikely. Performing TDE for CA without a detailed preoperative evaluation may worsen the outflow of CA by obstructing the TD. Therefore, when percutaneous transabdominal TDE (PTTDE) is performed in the case of CA, a detailed preprocedural evaluation such as lymphoscintigraphy or CL is necessary, and the leak point must be embolized without fail when embolization is performed. In TDE for chylothorax, a catheter tip can be advanced near the leak point and isolation can be performed, whereas TDE for CA requires blocking downstream of the TD with an embolic material such as a coil and then embolizing the leak point located upstream from the catheter tip with n-butyl-2-cyanoacrylate (NBCA) in a retrograde fashion. Yokokawa et al. [40] reported a CA case after laparoscopy-assisted distal gastrectomy and D2 lymph node dissection, which was successfully treated using PTTDE with coil embolization of the upper site of the TD and a 20% NBCA: Lipiodol injection. However, to date, no other clinical research has been conducted on the use of PTTDE for CA treatment.

Although PTTDE is a very low-risk procedure, there can be rare complications. Schild et al. [41] analyzed 35 patients by CT after PTTDE and found one perihepatic hemorrhage and one periaortic hematoma without any additional treatment. Solitary cases of bile peritonitis and pancreatitis have also been noted. They mentioned that preprocedural ultrasound scanning may avert puncturing the gallbladder [41]. Should a patient show symptoms after embolization, other authors recommend that CT should be performed without hesitation [34].

Lymphopseudoaneurysm embolization/Sclerotherapy

Sclerotherapy or embolization can also be adapted for CA treatment when a patient with an lymphopseudoaneurysm (LPA) (Fig. 4), which is defined as a small cavity of lymph collection that is directly extravasated from the lymphatic vessels or lymph nodes. It is contained in the surrounding tissue before draining into larger spaces such as the peritoneal cavity, or into lymphoceles [40, 42]. There are some reports of CA treatment with LPA embolization using NBCA with or without coils [9, 42, 43]. Kwon et al. [42] retrospectively investigated six patients who had refractory CA after retroperitoneal surgery, and all patients were successfully treated using 33% to 50% NBCA injected from a placed catheter without any complications. Nadolski et al. [9] reported that a chylous LPA was punctured with a 22 G needle under fluoroscopy guidance, after which a microwire was advanced into the cavity and a needle was exchanged for a microcatheter. Embolization was then performed with coils and NBCA from the inserted microcatheter [9]. Another case report was treated with CT-guided catheter insertion and embolization [43]. However, no reports could be found using another agent for abdominal chylous leaks.

Figure 4.

A 50-year-old female with CA after left radical nephrectomy. (a) Intranodal lymphangiography was performed, and contrast extravasation was confirmed in the left lumber lymphatic tract (black arrow). (b) Enlarged view near the extravasation. (c) A small lymphatic duct (white arrow) connecting to extravasation (black arrow) was recognized, and lymphatic duct puncture and embolization were attempted but failed.

(d) RTV was attempted but the catheter could not be inserted into the terminal TD due to a lymph node-like structure present in the terminal TD (white arrow). (e) CT was then acquired, and a chylocele (white arrow) was found in the left posterior of the abdominal aorta. (f) Percutaneous drainage and embolization with NBCA were performed. NBCA casts spreading in the longitudinal direction can be seen due to repeated embolization (white arrow). Contrast enhancement from the inserted catheter just before embolization (black arrow). The chyle leak was stopped after this embolization.

CA: chylous ascites; NBCA: n-butyl-2-cyanoacrylate; RTV: retrograde transvenous approach; TD: thoracic duct

Lymph node embolization

After lipiodol lymphangiography is performed, if lymphatic extravasation was identified along the course of the pelvic sidewall or retroperitoneal lymphatic vessel, the nearest upstream lymph node should be punctured using a small-sized needle (22-25 G). It is not necessarily a single lymph node that is involved, and if possible, the surrounding lymph nodes should also be considered for embolization. This technique is useful for treating leaks from small lymphatic vessels which cannot be catheterized. Hur et al. [22] reported direct puncture of the lipiodol-stained lymph node could be easily performed under fluoroscopy and/or CT. The ratio of glue to lipiodol should be adjusted according to the extent of the target embolization taking care of premature polymerization [22, 44].

Clinical failures may result from a complex network of collaterals or multiple leakage sites that cannot be visualized by intranodal lymphangiography. Therefore, repeated embolization should be considered [45]. Nadolski et al. [9] reported six CA cases were treated successfully using proximal lymph node embolization.

Retrograde transvenous lymphatic embolization

The retrograde transvenous (RTV) approach is a primary or secondary method for TD approach intervention, which was introduced in 2008. Kim et al. [46] reported that the retrograde TD cannulation rate was as high as 70%. In this study, intranodal lymphangiography was performed to evaluate the morphology of the terminal TD before starting RTV, and it was concluded that the engagement of a shaped diagnostic catheter into the jugulovenous junction and the presence of a dominant channel in the terminal TD were prognostic factors for a successful RTV [46].

RTV can be a bailout technique not only for PTTDE, but also for the treatment of CA. A few case reports of treatment with retrograde TDE for CA have been published [47, 48]. When antegrade lymphangiographies such as inguinal intranodal lymphangiography or lymphatic scintigraphy could not confirm the leak point of CA due to disrupted pelvic or retroperitoneal lymphatic ducts caused by lymphatic dissection, or when the leak point was out of line from the lymphatic chain due to intranodal injection, retrograde transvenous lymphangiography and embolization may be used to approach the leak point (Fig. 5). Although some authors reported without balloon catheter embolization [47], theoretically, balloon-occluded embolization may be reasonable, both in terms of delivering contrast material or embolic liquid to the leak point and preventing pulmonary embolisms due to reflux [48]. Catheter adhesion is also less likely because, unlike blood, the polymerization time of NBCA in lymph fluid is longer, especially in chyle [49]. NBCA polymerizes upon exposure to anions, zwitterions, and free radicals. Although the electrolyte levels in plasma and lymph are similar, the concentrations of fat (chylomicrons, triglycerides (TGs), and fat-soluble vitamins) are quite different. Previous studies have shown that a high TG concentration extends the polymerization time of NBCA [50].

Figure 5.

A 60-year-old female with CA after adnexectomy and retroperitoneal lymphadenectomy. Intranodal lymphangiography was invalid due to disruption of the bilateral pelvic lymph tract. (a) RTV and retrograde ductography were performed and recognized normal type TD (black arrow). (b) A microcatheter was advanced to below the diaphragm and contrast extravasation was recognized in the left lumber tract (black arrow). Embolization was then performed using 50% NBCA; Lipiodol and CA were improved.

CA: chylous ascites; NBCA: n-butyl-2-cyanoacrylate; RTV: Retrograde transvenous approach; TD: thoracic duct

Hepatic lymphatic embolization

Liver lymphatic flow is divided into deep and superficial systems. The deep lymphatic tract is further divided into the hepatic vein tract and portal tract. Lymphatic flow toward the hepatic hilum in the portal tract can be the cause of peritoneal lymphorrhea and is located in the periportal area as well as the intrahepatic bile duct.

Cope demonstrated the liver lymphatic duct in 47% of patients for attempting transhepatic cholangiography using a 27 G micropuncture needle [51]. This finding has been applied to intrahepatic lymphangiography and embolization. Guez et al. [52] demonstrated hepatic lymphangiography and subsequently embolized with Onyx for hepatic lymphorrhea using 21 G and 27 G coaxial needle techniques.

Hepatic lymphatics communicate with the intestinal lymphatics through multiple channels; liver lymphangiography can sometimes elucidate CA, but not always [53]. There are few case reports that treated liver lymphatic embolization for CA. Nguyen et al. [54] reported a case of treated CA after pancreaticoduodenectomy using Aetoxisclerol foam. At our institution, we treated one case (not published) with hepatic lymphatic embolization using NBCA (Fig. 6).

Figure 6.

A 70-year-old female with invasive clear cell carcinoma who had undergone right nephrectomy with total tumor removal, including the removal of retroperitoneal and intra-IVC lesions. Five days after surgery, chylous ascites were observed, which did not improve with conservative treatment. Lymphoscintigraphy did not show leakage, and CT did not show lymphopseudoaneurysm. (a) Eighteen days post-surgery, we attempted retrograde transvenous thoracic duct cannulation with inguinal intranodal lymphangiography; however, this failed due to the plexiform shape of the terminal TD. (b) Then, we attempted hepatic lymphangiography using iodine contrast material. (c, d) Posthepatic lymphangiography CT showed the lymphatic duct in the hepato-duodenal ligament (white arrow) and contrast accumulation in the peritoneal cavity (black arrow). Therefore, embolization was performed through the hepatic lymphatic ducts using 20% NBCA, and the chylous ascites subsequently improved.

IVC: inferior vena cava; NBCA: n-butyl-2-cyanoacrylate; TD: thoracic duct

Peritoneovenous shunt

Peritoneovenous shunt (PVS) is a permanent placement catheter system under the skin that connects the peritoneal cavity to the superior vena cava. This system has two catheter limbs with an interposed single or double-valved unidirectional pump. A valve should be placed upon the rib to facilitate pressing the pump button.

This system is a permanent placement device and indirectly affects chyle leaks. In addition, there have been a few reports of disseminated intravascular coagulation (DIC), as well as problems such as CA recurrence due to thrombotic occlusion; device replacement is needed in this case. Therefore, this system is considered an important last resort, this device should be placed after considering the patient's condition, providing sufficient information regarding the need for regular follow-up, and explaining the burden following its use. Yarmohammadi et al. [55] investigated 20 patients who had been placed PVS for postoperative CA. The clinical success rate was 90%, leading to shunt removal in 85% of patients between 46 and 481 days. The total complication rate was 40%, with the most common complication being occlusion (30%). Subclinical DIC was observed in one patient without additional treatment [55]. In this study, patients were taught to press the button 20 times in the morning and before going to bed. However, the number and intervals of pressing the button seem low and should be increased to prevent occlusion. There was no mention of anticoagulant administration, and although there is no consensus, direct oral anticoagulant should be considered to prevent catheter occlusion.

Conclusions

Postoperative CA is a life-threatening condition, and IR has become an indispensable tool for its treatment, owing to its minimal invasiveness, feasibility, and safety. This review describes the anatomy, physiology, and imaging related to IR, as well as IR techniques and strategies for postoperative CA. Familiarity with this knowledge and these techniques is thought to lead to safe and reliable interventions.

Conflict of Interest

None

Author Contribution

Drafting of the manuscript: H.A.

Creating illustrations and images: S.K.

Evaluating text and searching literature: K.E.

Correcting and supervising the content: H.O.