A rare complication of hysterosalpingography: A case report of venous intravasation.

A 26-year-old woman was referred for HSG as part of the evaluation for primary infertility. She reported regular menstrual cycles and had no history of pelvic inflammatory disease, uterine surgery, recent abortion, abnormal uterine bleeding, or prior gynecologic instrumentation. Physical examinations and baseline laboratory investigations were unremarkable. HSG was performed during the early follicular phase (day 8 of the menstrual cycle) to minimize the likelihood of pregnancy and reduce endometrial thickness. Written informed consent was obtained. The procedure was conducted under fluoroscopic guidance using aseptic technique. After cervical visualization with a speculum, topical anesthesia was applied, and a cervical cannula was gently positioned. A nonionic, water-soluble iodinated contrast agent (Omnipaque) was manually injected at low pressure. Following administration of approximately 5 mL of contrast, fluoroscopy revealed immediate opacification of multiple reticular and tubular parauterine structures, consistent with early filling of the parauterine venous plexus. The uterine cavity and fallopian tubes were not visualized. Delayed images demonstrated progressive opacification of the gonadal veins, followed by rapid washout of contrast from the pelvic venous system within 1 minute ( Fig. 1 ). Fig. 1 (A) Fluoroscopic image obtained immediately after injection of 5 mL of contrast medium demonstrates early opacification of multiple parauterine tubular (curved arrows) and reticular (circle) venous structures, consistent with venous intravasation. (B) Delayed image acquired 30 seconds after contrast injection shows progressive washout of contrast from the pelvic venous plexus. (C) Image obtained 1 minute after contrast injection demonstrates near-complete washout of pelvic veins with residual opacification of the gonadal veins (thick arrows). Fig 1 dummy alt text (A) Fluoroscopic image obtained immediately after injection of 5 mL of contrast medium demonstrates early opacification of multiple parauterine tubular (curved arrows) and reticular (circle) venous structures, consistent with venous intravasation. (B) Delayed image acquired 30 seconds after contrast injection shows progressive washout of contrast from the pelvic venous plexus. (C) Image obtained 1 minute after contrast injection demonstrates near-complete washout of pelvic veins with residual opacification of the gonadal veins (thick arrows). The patient experienced no pain, allergic reaction, or hemodynamic instability. The procedure was immediately discontinued upon recognition of venous intravasation. Alternative imaging modalities were recommended.

Complete written informed consent was obtained from the patient for the publication of this study and accompanying images.

Severe venous intravasation is a rare but diagnostically significant complication of HSG. Prompt recognition of its characteristic fluoroscopic appearance is essential to prevent misinterpretation and potential systemic complications. Adherence to appropriate technique, careful contrast administration, and awareness of intravasation patterns are critical for ensuring patient safety and maintaining the diagnostic integrity of HSG. Further studies are warranted to refine preventive protocols and compare outcomes with alternative infertility imaging modalities.

Venous intravasation represents an uncommon but important complication of HSG, with reported incidence ranging from 0.4% to 6.9% [ [5] , [6] , [7] , [8] ]. It occurs when contrast traverses disrupted endometrial or myometrial venous channels, typically under conditions of increased intrauterine pressure or altered vascular permeability [ 1 , 6 ]. The classification system proposed by Dusak et al. [ 1 ] stratifies intravasation into 4 levels based on extent and speed of venous involvement. The present case fulfills criteria for level-3 intravasation, characterized by rapid progression from myometrial veins to major pelvic and gonadal veins. This severe form is particularly relevant due to its potential association with systemic complications when oil-based contrast agents are used. Predisposing factors described in the literature include recent uterine trauma, endometriosis, pelvic infection, abnormal uterine bleeding, and secondary infertility [ 1 , 6 ]. Notably, none were present in our patient, highlighting that venous intravasation may occur even in the absence of identifiable risk factors. From an imaging perspective, differentiation between venous intravasation and intraperitoneal contrast spillage is critical. Venous intravasation demonstrates a fine reticular or tubular vascular pattern, rapid washout, and delayed renal excretion of contrast, whereas intraperitoneal spill persists within the peritoneal cavity without clearance [ 1 , 6 ]. Failure to recognize intravasation may lead to false assumptions of tubal patency or misinterpretation as vascular pathology. Preventive strategies include performing HSG during the early follicular phase, using water-soluble contrast agents, applying gentle and incremental injection pressure, and maintaining continuous fluoroscopic monitoring. Immediate cessation of contrast administration upon suspicion of intravasation is essential [ 1 , 6 , 9 , 10 ]. The limitations of this report include the lack of long-term follow-up and absence of comparative imaging; however, the case provides a clear demonstration of severe intravasation and reinforces key interpretive principles.

Hysterosalpingography (HSG) is a fluoroscopic examination used to evaluate uterine cavity morphology and fallopian tube patency through trans-cervical injection of iodinated contrast material. HSG plays a vital role in infertility workup due to its wide availability, low cost, and combined diagnostic and therapeutic value [ [1] , [2] , [3] ]. Although HSG is considered a safe procedure, it is not without risk. Commonly reported adverse effects include pelvic pain, vasovagal reactions, infection, and uterine perforation. Less frequently, contrast intravasation may occur, whereby contrast medium enters the uterine or parauterine venous circulation instead of outlining the uterine cavity and fallopian tubes [ 1 , 4 ]. While often clinically silent when water-soluble contrast agents are used, venous intravasation may lead to diagnostic pitfalls and, in rare cases, serious complications such as embolic events—particularly with oil-based contrast media [ [5] , [6] , [7] ]. Previous studies have described the incidence, imaging patterns, and classification of venous intravasation; however, severe forms remain infrequently reported, and awareness among radiologists is variable. The present case is reported to illustrate the fluoroscopic appearance of severe venous intravasation, discuss its clinical implications, and reinforce preventive and interpretive strategies relevant to daily radiology practice.