Contrast media extravasation occupies an unusual position in modern radiology practice: it is simultaneously one of the most frequently encountered procedural complications and one of the least systematically studied. The reported incidence range of 0.1% to 1.2% may appear reassuringly narrow, but when applied to the enormous global volume of contrast-enhanced imaging—millions of examinations performed annually across hospitals of every size—the absolute number of affected patients becomes considerable. The recent analysis of 378,082 intravenous contrast-enhanced CT scans cited in the source literature underscores this point: even at the low end of the frequency spectrum, a busy imaging department can expect to encounter extravasation events on a regular basis, making familiarity with recognition and management protocols a practical necessity rather than an academic exercise.

The severity grading framework used in the radiology literature helps to contextualize why the blistering described in this case deserves attention. In the national registry analysis of 1,085 extravasation events, the overwhelming majority—94.6%—were classified as mild injuries, typically limited to swelling and discomfort that resolve without specific intervention. Moderate injuries accounted for 4.7% of events, and severe injuries for only 0.8%. Yet the outcome data attached to these categories reveal a striking pattern: in the observational cohort with detailed follow-up, 29 of 32 patients with moderate extravasation developed skin blisters, with a mean recovery time of five days and a range spanning two to twelve days. All five patients with severe extravasation developed blisters as well, and their recovery was markedly prolonged, averaging 23 days with a range of 17 to 30 days. Blister formation, in other words, functions as a clinical marker that the injury has crossed from trivial into a more consequential category, and it is precisely this transition that the present case illustrates.

Several patient-specific and procedural factors converge to explain why a relatively modest estimated extravasated volume of approximately 5 mL could produce tense, fluid-filled blisters within five hours. The osmolality and viscosity of the contrast agent, the injection rate, the volume delivered before the injection was halted, and the anatomical characteristics of the injection site all influence the degree of tissue injury. Iobitridol at 350 mgI/mL is a non-ionic low-osmolar agent, a class considerably safer than the older ionic high-osmolar compounds, but hyperosmolarity remains an inherent property of iodinated contrast. When such fluid enters the interstitial space, it creates an osmotic gradient that draws additional water into the tissue, amplifying swelling and pressure. The power injector flow rate of 3.5 to 4.0 mL/s used for lower-extremity CT angiography, while standard for vascular imaging, delivers contrast under sufficient pressure to dissect along tissue planes once the vessel wall is breached. The forearm, with its relatively tight fascial compartments and thin overlying skin, offers less accommodating space for leaked fluid than looser subcutaneous regions, which may partly explain the rapid emergence of blistering at this site.

The temporal course of the injury is also instructive. The patient reported distending pain at the puncture site during injection—an early warning sign that prompted immediate termination of the injection at 80 mL delivered—and bedside ultrasound subsequently quantified the residual extravasated volume. Yet the visible skin changes did not appear immediately. Only at routine nursing rounds five hours later did the blisters become evident, on a background of erythema and mild swelling. This delayed presentation reflects the physiology of contrast-induced tissue injury: osmotic fluid shifts, inflammatory mediator release, and endothelial changes evolve over hours rather than seconds. The practical implication is that a patient who appears unharmed immediately after an extravasation event still requires structured follow-up observation, as the source case demonstrates through hourly nursing reassessment of the affected limb.

Equally important is what the clinical course did not show. At no point did the patient develop evidence of compartment syndrome—the most feared complication of large-volume extravasation, in which rising interstitial pressure within a confined fascial space compromises capillary perfusion and threatens nerve and muscle viability. The assessment of capillary refill, distal sensation, and passive finger movement, repeated throughout the observation period, represents the bedside evaluation that nursing and medical staff should perform whenever significant extravasation occurs. Pain that intensifies with passive stretch, progressive swelling with tenseness of the compartment, paresthesia, and diminished pulse are the classic warning features, and their absence in this case allowed management to remain entirely conservative. The distinction matters because compartment syndrome from contrast extravasation, while rare, may necessitate urgent surgical fasciotomy, whereas blistering injuries without compartment involvement can generally be managed with topical and supportive measures.

The management regimen applied in this case draws on two distinct therapeutic traditions. Hirudoid cream, whose active constituent is mucopolysaccharide polysulfate, has long held a place in European and Asian practice for superficial phlebitis, bruising, and extravasation injuries. Its proposed mechanisms include anti-inflammatory effects on local tissue and promotion of connective tissue repair and resorption of edema. Guidelines from both the American College of Radiology and the European Society of Urogenital Radiology emphasize conservative first-line measures—cessation of injection, limb elevation, appropriate compresses, and close monitoring—with topical agents such as mucopolysaccharide polysulfate commonly incorporated into that framework. The intermittent ice compresses used here, applied for 15 to 20 minutes every 2 to 4 hours with a cloth barrier protecting the skin, serve the dual purpose of vasoconstriction, which limits further spread of the osmotically active contrast within the tissue, and mild analgesia. Cold application must be timed and barriered carefully, since prolonged direct icing risks adding a cold injury to the existing chemical one.

The third component, Jinhuang San—Golden Yellow Powder, also known by its fuller name Ru-Yi-Jin-Huang-San—is a classical traditional Chinese medicine external formula with a documented history of use for traumatic swelling, carbuncles, and drug extravasation injuries. The supporting evidence cited in the source literature is twofold. A clinical study found that early wet compresses with the formula shortened mean healing time of extravasation-induced skin injury to 6.44 days. Separately, an experimental model of iohexol extravasation demonstrated significant reductions in swelling area and inflammatory infiltration at 24 and 48 hours respectively. The preparation method used in this case—mixing the powder with green-tea water to form a wet poultice—follows customary practice, in which the tea may contribute additional astringent and anti-inflammatory properties while providing the moisture needed for transcutaneous delivery of the herbal constituents.

The rationale for combining these three modalities is plausible at the level of mechanism. Mucopolysaccharide polysulfate addresses inflammation and tissue repair; cold compresses limit the osmotic spread of the extravasated agent and relieve pain; and the herbal poultice, according to the experimental data, reduces both edema and the cellular inflammatory response. Each component targets a different phase or aspect of the injury process, and their combination is conceptually complementary rather than redundant. Nevertheless, the authors are appropriately careful to frame the outcome as hypothesis-generating. A single uncontrolled case cannot establish efficacy, and the natural history of even moderate extravasation injuries includes spontaneous improvement in many patients, making attribution of the rapid 48-hour resolution to the specific regimen inherently uncertain. Prospective, controlled studies would be required to determine whether this integrated approach genuinely accelerates healing compared with standard conservative care alone.

The patient’s underlying vascular disease adds a further dimension of clinical interest. Lower-extremity atherosclerotic occlusive disease, with the severe aortoiliac and iliac stenoses and occlusions documented on the completed CT angiography, indicates widespread arterial compromise. Although the extravasation occurred in the forearm rather than the diseased lower limbs, the systemic atherosclerotic burden raises questions about whether impaired microvascular reserve might influence tissue tolerance to interstitial contrast exposure. The patient’s preserved renal function, with estimated glomerular filtration rates above 125 mL/min/1.73 m² on both assessments, and her regimen of clopidogrel, atorvastatin, nifedipine, and telmisartan reflect the standard pharmacological management of high-risk atherosclerotic disease. Whether antiplatelet therapy, statin-associated effects on endothelial function, or antihypertensive agents modify the local inflammatory response to extravasated contrast remains unexplored, but such interactions represent a legitimate direction for future investigation.

From a prevention standpoint, the case reinforces several established principles of contrast administration. Power injectors deliver contrast at flow rates and pressures that exceed what manual injection can achieve, and they demand correspondingly careful venous access assessment before use. A 20-G peripheral cannula in a forearm vein is an appropriate choice for CT angiography, but cannula position, vein caliber, and patient factors such as fragile veins in older adults all influence extravasation risk. The patient’s complaint of distending pain at the puncture site, rated 6 on a 10-point numeric scale, functioned exactly as an early warning should: the injection was stopped immediately, the cannula removed, and the examination completed through a new puncture site. This responsiveness likely limited the extravasated volume and, by extension, the severity of the injury. Patient-reported symptoms during power injection should never be dismissed, because the interval between the first symptom and tissue damage can be short.

The reporting of this case according to the CARE guidelines also reflects a broader movement toward methodological rigor in case-based evidence. Single-case reports occupy the lowest tier of the evidence hierarchy, but they serve indispensable functions: they document rare presentations, describe novel management combinations, and generate testable hypotheses for controlled research. The observation that blistering from iobitridol extravasation resolved within 48 hours under a three-component topical regimen, without skin breakdown, provides a concrete clinical trajectory that future studies can measure against. Until such studies exist, the case stands as a well-documented example of early recognition, structured multidisciplinary management, and a favorable outcome in an uncommon manifestation of a common complication.

For clinicians and nursing teams, the practical takeaways are straightforward. Every contrast-enhanced examination carries a small but real extravasation risk; patients should be monitored both during and after injection, with particular vigilance in the hours following an event; blistering signals a moderate-to-severe injury requiring escalation of care; and conservative management—elevation, appropriate compresses, topical agents, and serial assessment for compartment syndrome—remains the cornerstone of treatment for injuries without surgical indications. The integration of traditional Chinese medicine external therapies with conventional topical treatment, while promising in this instance, should be viewed as an avenue for further research rather than a settled standard, and the authors’ call for prospective controlled studies is a fitting conclusion to a carefully documented clinical observation.

Subject of Research: …

Article Title: Contrast media extravasation following CT angiography in a patient with lower-extremity atherosclerotic occlusive disease: a case report

Article References: Yan, C., Zhang, T., Xu, Q., & Bi, S. (2026). Contrast media extravasation following CT angiography in a patient with lower-extremity atherosclerotic occlusive disease: a case report. Frontiers in Medicine, 13, Article 1888394. https://doi.org/10.3389/fmed.2026.1888394

Image Credits: AI Generated

DOI: 10.3389/fmed.2026.1888394

Keywords: Contrast, media, extravasation, following, angiography, patient, lower-extremity, atherosclerotic, occlusive, disease, case, report

Hepatocellular carcinoma is the most common primary liver malignancy, accounting for 85 to 90 percent of cancers that originate in liver cells, and it ranks as the third leading cause of cancer-related death worldwide. For patients with intermediate-stage disease and preserved liver function, transarterial chemoembolization, or TACE, is a cornerstone of care under the Barcelona Clinic Liver Cancer staging system. The procedure exploits a biological quirk: liver tumors draw their blood supply almost exclusively from the hepatic arteries, while healthy liver tissue depends on the portal vein. By threading a catheter into the arteries feeding the tumor and delivering a mixture of chemotherapy and an oily contrast agent called lipiodol, followed by embolization with gel foam slurry, interventional radiologists can concentrate a cytotoxic assault on the tumor while starving it of blood.

Yet the very act of delivering that assault exposes the hepatic vasculature to a barrage of insults. Catheters and guidewires scrape the vessel walls. Lipiodol and antimitotic drugs such as epirubicin exert corrosive and chemical effects on the delicate endothelial lining. Temporary embolization produces ischemic stress, and patients with chronic liver disease already harbor dysfunctional endothelium that may be poorly equipped to recover. Despite decades of TACE practice, the literature on what actually happens to the native hepatic arteries after treatment has remained surprisingly thin, prompting the research team to investigate systematically.

The researchers, led by interventional radiologists at the Sree Chitra Tirunal Institute for Medical Sciences and Technology in Thiruvananthapuram, Kerala, combed hospital records for all adult patients with chronic liver disease who underwent more than one session of TACE between January 2018 and June 2023. Of 394 patients treated during that window, 69 had undergone repeat sessions, and 58 had angiographic images of sufficient quality for analysis. The team deliberately excluded patients who had received other locoregional therapies, such as radiofrequency ablation, between TACE sessions, to keep the vascular picture as clean as possible.

The analytical framework was elegantly simple. The hepatic vasculature was divided into three anatomical zones: the proximal zone comprising the common hepatic artery and hepatic artery proper, the intermediate zone covering lobar and segmental branches, and the distal zone encompassing the subsegmental branches that represent the liver’s microvascular frontier. Injury was graded on a four-point ordinal scale, ranging from Grade 0 for a normal appearance or mild irregularity, through Grade 1 for mild stenosis of about 50 percent, to Grade 2 for severe stenosis or complete occlusion, and Grade 3 for the presence of pseudoaneurysms or dysplastic arterial changes. Grades 0 and 1 were classified as low-grade injury, while Grades 2 and 3 counted as high-grade. Two radiologists with ten and five years of gastrointestinal imaging experience independently reviewed paired angiograms obtained at least six weeks apart, blinded to clinical details.

The results painted a strikingly zonal picture. In the proximal vessels, 98.3 percent of patients showed Grade 0 injury and the remainder Grade 1, with no high-grade damage at all, and statistical testing confirmed no significant change before and after the first TACE session. The intermediate zone told a different story: 84.5 percent of patients had Grade 0 injury, but 13.8 percent showed Grade 1 and 1.7 percent showed Grade 2, a distribution that shifted significantly after treatment. The distal subsegmental vasculature fared worst of all, with 53.4 percent of patients at Grade 0, 31 percent at Grade 1, 13.8 percent at Grade 2, and 1.7 percent at Grade 3, meaning roughly 12 to 15.5 percent of patients developed high-grade injury to the liver’s smallest arteries. The Mann-Whitney U-test yielded p-values of 0.002 for the intermediate zone and 0.001 for the distal zone, while the proximal zone showed no significant difference. Interobserver agreement was strong, with a correlation coefficient of 0.913.

To understand why some patients’ microvasculature fared worse than others, the team turned to multinomial logistic regression, feeding in demographic, biochemical, clinical and procedural variables. Three factors emerged as independent predictors of high-grade distal arterial injury: the Child-Pugh score, a measure of liver functional reserve; the presence of diabetes; and the delta time, the interval in weeks between successive TACE sessions. Each carried a statistically significant association, with p-values of 0.031, 0.045 and 0.004 respectively. Notably, no variable predicted high-grade injury in the lobar and segmental vessels, reinforcing the impression that the microvasculature is uniquely vulnerable.

The biology behind these predictors is plausible. Diabetes is well known to impair endothelial function and blunt vascular healing, and prior work has shown that adequate glycemic control in TACE patients is associated with improved progression-free survival. Deteriorating liver function, captured by the Child-Pugh score, is likewise linked to poor endothelial resilience and impaired microvascular recovery. The delta time finding may be the most immediately actionable: shorter intervals between embolization sessions give the injured native vasculature less time to recover, so repetitive injury at close intervals compounds itself. This inverse relationship between retreatment interval and vascular damage could inform scheduling decisions, suggesting that clinicians may want to prioritize vascular recovery when planning repeat interventions rather than compressing the timeline.

The clinical stakes are considerable. Patency of segmental and subsegmental arteries is paramount for delivering a second round of chemoembolization to residual or recurrent tumor, so distal vascular injury could compromise both the feasibility and efficacy of retreatment, and may even encourage the tumor to recruit alternative extrahepatic blood supplies. Conversely, the apparent invulnerability of the proximal hepatic arteries is reassuring for the substantial subset of patients who undergo TACE as a bridge to liver transplantation, since damage to the main hepatic artery could complicate the transplant operation itself. Prior multicenter analyses of more than 800 patients who received TACE before transplantation found no increased need for intraoperative hepatic artery interventions, a conclusion this study’s proximal findings echo. The authors also raise the possibility that transarterial radioembolization, generally considered gentler on the vasculature, may be preferable for patients anticipated to need multiple locoregional treatments.

The study has limitations that temper but do not erase its message. It assessed only the changes following the first TACE session to maintain homogeneity, so cumulative injury from multiple sessions remains unmeasured. It was a single-center analysis with a modest sample, and all patients received conventional TACE rather than drug-eluting bead or balloon-occlusion variants, so the findings may not generalize to those techniques. Still, the authors report that no previous study has systematically documented the incidence of hepatic arterial injury after chemoembolization, making this a genuine first. Larger, prospective, multicenter trials will be needed to confirm the predictors and to determine whether protecting the liver’s smallest arteries can translate into better outcomes for patients facing repeated rounds of therapy against one of the world’s deadliest cancers.

Subject of Research: Vascular injury to hepatic arteries following transarterial chemoembolization for hepatocellular carcinoma

Article Title: Angio-architectural changes in hepatic arteries following conventional transarterial chemoembolization for hepatocellular carcinoma and the factors influencing them: a retrospective observational study

Article References: Arunachalam, V. S., Sharma, S., Ayyappan, A., Alex, A., & Valakkada, J. (2025). Angio-architectural changes in hepatic arteries following conventional transarterial chemoembolization for hepatocellular carcinoma and the factors influencing them: a retrospective observational study. CVIR Oncology, 1(1), Article 28. https://doi.org/10.1007/s44343-025-00028-w

Image Credits: AI Generated

DOI: 10.1007/s44343-025-00028-w

Keywords: hepatocellular carcinoma, transarterial chemoembolization, hepatic artery, vascular injury, interventional radiology, angiography, microvasculature, Child-Pugh score, diabetes, lipiodol, liver cancer, endothelial dysfunction