Iliac vein variation in the sacral promontory on three-dimensional computed tomography angiography: a prospective observational study before laparoscopic sacrocolpopexy.

INTRODUCTION AND HYPOTHESIS: Venous injury may occur during exposure of the anterior longitudinal ligament at the anterior sacral promontory (SP). We aimed to quantitatively measure the extent of the vascular window (VW) in front of the SP in patients with internal iliac vein (IIV) variations using preoperative three-dimensional computed tomography angiography (3DCTA). We hypothesized that patients with IIV variations would have a narrow VW. METHODS: This prospective observational study included patients scheduled for laparoscopic sacrocolpopexy (LSC) between July 2022 and April 2023 who underwent preoperative 3DCTA. The primary endpoint was the VW measurement in the standard and variant IIV groups using 3DCTA before LSC. The secondary endpoint was the difference between the two IIV groups adjusted for age, body mass index, hypertension, and diabetes using an analysis of covariance (ANCOVA) model. Multiple regression analysis was performed to analyze the effect of factors on the distance from the SP to great vascular bifurcations. RESULTS: There were 20 cases of IIV variation (20.2%). VW was 28.8 ± 12.4 mm in the variant group and 39.6 ± 12.6 mm in the standard group (p = 0.001). In the ANCOVA model, IIV variations affected VW (coefficient, -11.8; 95% confidence interval [CI], -18.4 to -5.08, p < 0.001). Multivariate analysis revealed that the aorta-SP distance decreased with age (coefficient, -0.44; 95% CI, -0.77 to -0.11, p = 0.009). CONCLUSIONS: One in five women has a vascular variant at the SP that restricts the "safe" zone of fixation to < 3 cm.

Effects of cycle periods and pressure amplitudes of alternating pressure on sacral skin blood flow responses.

BACKGROUND: There are no guidelines on selecting alternating pressure (AP) configurations on increasing sacral skin blood flow (SBF). AIM: The specific aims were to compare different cycle periods and pressure amplitudes of AP on sacral SBF responses in healthy people to establish the efficacy and safety of the protocols. METHODS: Two studies were tested, including the cycle period study (8 2.5-min vs 4 5-min protocols) and the pressure amplitude study (75/5 vs 65/15 mmHg protocols). Sacral SBF was measured using laser Doppler flowmetry (LDF) in 20 participants. AP loads were randomly applied using an indenter through the rigid LDF probe. Each protocol included a 10-min baseline, 20-min AP and 10-min recovery periods. A 30-min washout period was provided. The SBF response was normalized to the baseline SBF of each condition of each participant. RESULTS: For the cycle period study, the 4 5-min cycle protocol partially restored more SBF than the 8 2.5-min cycle protocol at the low-pressure phase (0.87 ± 0.04 vs 0.71 ± 0.03, p < 0.05) and at the high-pressure phase (0.25 ± 0.03 vs 0.19 ± 0.03, p < 0.05). For the pressure amplitude study, the 75/5 mmHg protocol partially restored more sacral SBF than the 65/15 mmHg protocol at the low-pressure phase (0.87 ± 0.1 vs 0.25 ± 0.03, p < 0.05) but not at the high-pressure phase (0.23 ± 0.02 vs 0.21 ± 0.02, non-significant). CONCLUSION: This study demonstrated that 1) a cycle period of 5 min was better than 2.5 min and 2) a pressure amplitude of 75/5 mmHg was better than 65/15 mmHg. The finding provides insights for selecting the AP configurations for increasing SBF.

Fetal median sacral artery anatomy study by micro-CT imaging.

PURPOSE: The median sacral artery (MSA) is the termination of the dorsal aorta, which undergoes a complex regression and remodeling process during embryo and fetal development. The MSA contributes to the pelvic vascularization and may be injured during pelvic surgery. The embryological steps of MSA development, anastomosis formation and anatomical variations are linked, but not fully understood. METHODS: The pelvic vascularization and more precisely the MSA of a human fetus at 22 weeks of gestation (GW) were studied using micro-CT imaging. Image treatment included arterial segmentations and 3D visualization. RESULTS: At 22 GW, the MSA was a well-developed straight artery in front of the sacrum and was longer than the abdominal aorta. Anastomoses between the MSA and the internal pudendal arteries and the superior rectal artery were detected. No evidence was found for the existence of a coccygeal glomus with arteriovenous anastomosis. CONCLUSIONS: Micro-CT imaging and 3D visualization helped us understand the MSA central role in pelvic vascularization through the ilio-aortic anastomotic system. It is essential to know this anastomotic network to treat pathological conditions, such as sacrococcygeal teratomas and parasitic ischiopagus twins (for instance, fetus in fetu and twin-reversed arterial perfusion sequence).

Characterization of the median sacral artery course at the sacral promontory using contrast-enhanced computed tomography.

INTRODUCTION AND HYPOTHESIS: Laparoscopic sacral colpopexy (SC) is increasingly utilized in the surgical management of apical prolapse. It involves attachment of a synthetic mesh to the sacral promontory and to the prolapsed vaginal walls. The median sacral artery (MSA) runs close to the site of mesh attachment and is therefore prone to intraoperative injury, which may lead to profound hemorrhaging. The aim of this study was to determine the location of the MSA at the level of the sacral promontory with regard to adjacent visible anatomical landmarks. Surgeons may use this information to reduce the risk for presacral bleeding. METHODS: Sixty consecutive contrast-enhanced pelvic computed tomography scans were revised, and the location of the MSA at the level of the sacral promontory was determined in relation to the ureters, iliac arteries, sacral midline, and aortic bifurcation. RESULTS: The MSA runs 0.2 ± 3.9 mm left to the midline of the sacral promontory and 48.0 ± 15.4 mm caudal to the aortic bifurcation. The ureters, internal and external iliac arteries on the right were significantly closer to the MSA than on the left (30.0 ± 7.1 vs 35.2 ± 8.8 mm, p = 0.001; 21.5 ± 6.8 vs 30.3 ± 8.4 mm, p < 0.0001; 32.8 ± 10.2 vs 41.9 ± 14.5 mm, p = 0.005 respectively). CONCLUSIONS: The MSA, which runs left to the midline of the sacral promontory, and its location can be determined intraoperatively in relation to adjacent visible anatomical structures. The iliac vessels and ureter on the right are significantly closer to the MSA than those on the left. This information may help surgeons performing SC to avoid MSA injury, thus reducing operative morbidity.

Vascular anatomical relationships of the retropubic space and the sacrospinous ligament, using three-dimensional imaging.

INTRODUCTION AND HYPOTHESIS: Pelvic anatomy is complex and intimate knowledge of variabilities in anatomical relationships is critical for surgeons to safely perform surgical procedures. Three-dimensional Imaging provides the opportunity to analyze undisturbed anatomical relationships. The authors hypothesized that three-dimensional models created from pelvic computed tomography angiograms could be used to obtain vascular anatomical measurements, and that the measurements obtained from three-dimensional models would be similar to those from cadaver studies. METHODS: We included all pelvic computed tomography angiograms that were acquired in female patients older than 18 years at our institution within the previous 5 years. Three-dimensional models were created using the Invivo5 software based on the Digital Imaging and Communications in Medicine files. Structures of interest were virtually dissected and measured replicating previous cadaver studies. Statistical analysis of demographics and measurements was performed. RESULTS: The final analysis included 87 studies. The average age of the subjects was 66.9 years and their average BMI was 26.1 kg/m2. Of the 87 subjects, 12.6% had a history of hysterectomy, 2.3% a history of a continence procedure, and 1.1% a history of a prolapse procedure. The range of distance between the ischial spine and the pudendal artery was 3-17 mm. The closest vessels to the lower edge of the symphysis pubis were the obturator vessels. The aberrant corona mortis vessel was present in 27.9% of the subjects. Prior hysterectomy was associated with changes in the measurements of the obturator arteries with minimal changes in other measurements. CONCLUSIONS: Our results indicate that this technology provides similar measurements to those found in previous unembalmed cadaver studies. This technology offers a great opportunity to study anatomical relationships in a native undisturbed state.

Sacral epidural arteriovenous fistulas: imitators of spinal dural arteriovenous fistulas with different pathologic anatomy: report of three cases and review of the literature.

BACKGROUND: Sacral epidural arteriovenous fistulas (eAVFs) are rare and often misdiagnosed because of the incongruence between the thoracic level of clinical deficits and the sacral location of the offending pathology. Failure to diagnose this lesion delays treatment, resulting in prolonged venous hypertension in the cord, progressive neurological deterioration, and decreased chances of recovery. METHODS: A single-institution case series and the published literature were reviewed. RESULTS: Three patients had sacral eAVFs are located in the ventral epidural space with outflow connections to radicular veins that arterialized spinal cord veins, all presenting with thoracic myelopathy, venous engorgement, and delayed diagnosis. All eAVFs were occluded completely with radiographic and clinical improvement. CONCLUSIONS: Sacral eAVF pathophysiology, namely venous hypertension and compromised spinal cord circulation, is exactly the same as dural AVFs, as is their treatment: the interruption of outflow by occlusion of the draining vein, which effectively eliminates venous hypertension, without occlusion of the actual fistula itself. Epidural exposure of sacral eAVFs is not necessary, whereas complete intradural occlusion of their radicular drainage is. Draining radicular veins intermingle with the nerve roots and their occasional multiplicity makes them more difficult to identify intraoperatively.

The blood supply to the sacrotuberous ligament.

Knowledge of the vascular supply associated with the sacrotuberous ligament is incomplete, and at most attributed to a single coccygeal branch. Our aim was to investigate the sacrotuberous ligament vasculature with a focus on its origin and distribution. We dissected 21 hemipelvises (10 male and 11 female). The gluteus maximus was reflected medially, and a special emphasis was placed on the dissection of the vascular and neuronal structures. All specimens exhibited several (1-4) coccygeal arteries branching from the inferior gluteal artery penetrating the sacrotuberous ligament along its length. Seven specimens demonstrated the superior gluteal artery supplying sacral branches to the proximal superior border of the sacrotuberous ligament. Our study highlights several branches from a variety of origins as the supply to sacrotuberous ligament unlike previous reports stating only one vessel. Our results implicate surgical procedures in and around the area of the gluteal region such as decompressive procedures of the pudendal nerve, as it travels between the sacrotuberous and sacrospinous ligaments.

Blood flow responses over sacrum in nursing home residents during one hour bed rest.

OBJECTIVES: To describe individual BF responses in a nursing home resident population for one-hour periods of bed rest. METHODS: BF was measured for one hour over the sacrum in 0° supine position and 30° supine tilt position in 25 individuals aged 65 y or older while lying on a pressure-redistributing mattress. Measurements were made at three tissue depths (1, 2, and 10 mm) using the noninvasive optical techniques, LDF and PPG. RESULTS: Eleven participants had a PIV response at 1 mm depth in both positions and seven participants had a lack of this response at this depth and positions. The BF response at 1 mm depth appeared immediately and remained over, or below, baseline for the entire 60 min of loading in both positions. These BF patterns were also seen in deeper tissue layers. CONCLUSIONS: The cutaneous BF response among the nursing home residents was distinct, appeared early, and remained during the one hour of loading.

Weight-bearing-induced changes in the microtopography and structural stiffness of human skin in vivo following immobility periods.

Pressure ulcers (PUs) are injuries to the skin and underlying tissues, caused by sustained deformations and occur frequently in aged patients. Skin microtopography and stiffness affect the interaction of skin with contact surfaces contributing to PU development. We simulated immobility in 20 healthy females (mean age 69.9 years). Skin microtopography and stiffness were measured at the PU predilection sites before and after loading. Skin roughness decreased at the heels by 18.1% after 90 minutes (p = 0.022), but remained unchanged at the sacrum and the upper back. Structural elasticity and elastic deformations increased at all skin areas; changes over time were significant at the sacrum (p = 0.005) and the heel, (p = 0.002). The residual skin deformation increased at all skin areas after loading significantly at the sacrum (32.0%, p = 0.013) and upper back (20.6%, p = 0.007). The structural "biological" elasticity of the skin decreased significantly at the upper back after loading, but remained unchanged at the heels. All skin changes recovered after unloading. Results indicate that prolonged loading causes structural skin changes in humans in vivo in PU predilection sites. The pathogenesis of PUs is different at the heels, the sacral and upper back skin.

The surgical neurovascular anatomy relating to partial and complete sacral and sacroiliac resections: a cadaveric, anatomic study.

PURPOSE: Pelvic and sacral surgeries are considered technically difficult due to the complex multidimensional anatomy and the presence of significant neurovascular structures. Knowledge of the key neurovascular anatomy is essential for safe and effective execution of partial and complete sacral resections. The goal of this anatomic, cadaveric study is to describe the pertinent neurovascular anatomy during these procedures. METHODS: Three embalmed human cadaveric specimens were used. Sacrectomies and sacroiliac joint resections were simulated and the structures at risk were identified. Both anterior and posterior approaches were evaluated. RESULTS: During sacroiliac joint resection, L5 nerve roots are at high risk for iatrogenic injury; the vasculatures at greatest risk are the common iliac vessels and internal iliac vessels with L5-S1 and S1-S2 high sacrectomies. Minor bleeding risk is associated with S2-S3 osteotomy because of the potential to damage superior gluteal vessels. S3-S4 osteotomy presents a low risk of bleeding. Adjacent nerve roots proximal to the resection level are at high risk during higher sacrectomies. CONCLUSIONS: Several sacrectomy techniques are available and selection often depends on the specific case and surgeon preference; nevertheless, anatomic knowledge is extremely important. Considering the highly variable anatomic relations of the vascular bundles, a preoperative evaluation with CT or MRI with vascular reconstruction may be helpful to decrease bleeding risk by preemptively binding the internal iliac vessels in cases where higher tumors are present. To decrease the risk of damaging nerve roots, it is recommended to perform the resection as close to the involved foramina as possible.

Awareness of the median sacral artery during lumbosacral spinal surgery: an anatomic cadaveric study of its relationship to the lumbosacral spine.

PURPOSE: The purpose was to investigate the median sacral artery (MSA) anatomical pathway in terms of its relationship to the lumbosacral spine. METHODS: The posterior wall and lumbosacral spine of 54 adult embalmed cadavers were dissected. The MSA emerging point was identified. The distance from its emerging point to the lateral border of the vertebral body was measured bilaterally. The pathway of the MSA from the emerging point to the sacral promontory was described together with the MSA length. All outcomes were independently measured by two observers. Statistics on obtained data were calculated. RESULTS: Most of the MSA emerging points were at the L5 vertebral body (94.4 %). The emerging point from the right and left lateral border of the L5 vertebral body was 3.31 ± 0.54 cm and 2.39 ± 0.51 cm, respectively. The MSA then lay along the middle one-third of the anterior surface of the lumbosacral junction. The mean length between the emerging point and the sacral promontory was 2.73 ± 0.97 cm. CONCLUSIONS: The MSA anatomy is important for prevention of intra-operative bleeding. For anterior lumbosacral surgery, the MSA should be identified and controlled before proceeding with the spinal surgery. For posterior bicortical sacral screw placement, the screw tip should be fluoroscopically checked to avoid inserting the screw tip into the mid sacral promontory. By first approaching the anterior sacral promontory, the surgeon will find the MSA within the middle one-third zone, and 2.47-2.99 cm cephalad to this, the iliac vessels. Knowledge of the MSA helps the surgeon to operate more safely.

Microcirculatory responses of sacral tissue in healthy individuals and inpatients on different pressure-redistribution mattresses.

OBJECTIVE: The aim of this study was to explore the interaction between interface pressure, pressure-induced vasodilation, and reactive hyperaemia with different pressure-redistribution mattresses. METHOD: A cross-sectional study was performed with a convenience sample of healthy young individuals, and healthy older individuals and inpatients, at a university hospital in Sweden. Blood flow was measured at depths of 1mm, 2mm, and 10mm using laser Doppler flowmetry and photoplethysmography. The blood flow, interface pressure and skin temperature were measured in the sacral tissue before, during, and after load while lying on one standard hospital mattress and three different pressure-redistribution mattresses. RESULTS: There were significant differences between the average sacral pressure, peak sacral pressure, and local probe pressure on the three pressure-redistribution mattresses, the lowest values found were with the visco-elastic foam/air mattress (23.5 ± 2.5mmHg, 49.3 ± 11.1mmHg, 29.2 ± 14.0mmHg, respectively). Blood flow, measured as pressure-induced vasodilation, was most affected in the visco-elastic foam/air group compared to the alternating pressure mattress group at tissue depths of 2mm (39.0% and 20.0%, respectively), and 10mm (56.9 % and 35.1%, respectively). Subjects in all three groups, including healthy 18-65 year olds, were identified with no pressure-induced vasodilation or reactive hyperaemia on any mattress (n=11), which is considered a high-risk blood flow response. CONCLUSION: Interface pressure magnitudes considered not harmful during pressure-exposure on different pressure-redistribution mattresses can affect the microcirculation in different tissue structures. Despite having the lowest pressure values compared with the other mattresses, the visco-elastic foam/air mattress had the highest proportion of subjects with decreased blood flow. Healthy young individuals were identified with the high-risk blood flow response, suggesting an innate vulnerability to pressure exposure. Furthermore, the evaluation of pressure-redistribution support surfaces in terms of mean blood flow during and after tissue exposure is not feasible, but assessment of pressure-induced vasodilation and reactive hyperaemia could be a new way to assess individualised physiological measurements of mechanisms known to be related to pressure ulcer development.

Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: A Technical Note and Literature Review.

BACKGROUND: Sacral extradural arteriovenous fistula (SEAVF) is relatively rare, and its etiology is unknown. They are mostly fed by the lateral sacral artery (LSA). For endovascular treatment, both the stability of the guiding catheter and accessibility of the microcatheter to the fistula, distal to the LSA are required for sufficient embolization of the fistulous point. Cannulation of these vessels requires either crossover at the aortic bifurcation or retrograde cannulation using the transfemoral approach. However, atherosclerotic femoral and tortuous aortoiliac vessels can make the procedure technically difficult. Although the right transradial approach (TRA) can reduce this difficulty by straightening the access route, a potential risk remains for cerebral embolism because it passes the aortic arch. Herein, we present a case of successful embolization of a SEAVF using a left distal TRA. METHODS: We report a case of a 47-year-old man with SEAVF treated with embolization using a left distal TRA. Lumbar spinal angiography showed a SEAVF with an intradural vein through the epidural venous plexus fed by the left LSA. A 6-French guiding sheath was cannulated into the internal iliac artery via the descending aorta using the left distal TRA. A microcatheter could be advanced into the extradural venous plexus over the fistula point from the intermediate catheter placed at the LSA. Embolization with coils and n-butyl cyanoacrylate was successfully performed. RESULTS: The SEAVF completely disappeared on neuroimaging, and the patient gradually recovered. CONCLUSIONS: Left distal TRA could be a useful, safe, and less invasive option for the embolization of SEAVF, especially for patients with high-risk factors for aortogenic embolism or puncture site complications.

Wavelet analysis of sacral tissue oxygenation oscillations by near-infrared spectroscopy in persons with spinal cord injury.

The objective of this study is to assess the blood oxygenation oscillations in the tissue over the sacrum, a high risk area for pressure ulcer, using spectral analysis of near-infrared spectroscopy (NIRS) signals based on wavelet transform. A total of twenty subjects were recruited for this study, of which ten were persons with spinal cord injury (SCI) (3 women, 7 men, age=34.5±5.2years) and the other ten were healthy subjects (3 women, 7 men, age=36.5±6.2years). Waterlow Scale was used for the pressure ulcer risk assessment. External pressure of 26.6kPa (200mm Hg) was applied to the sacrum via a specifically designed indentor. The loading duration was 3min. The subjects were examined lying face-down. Tissue oxygenation signal was monitored for 20min prior to and after the loading period from the tissue over the sacrum area using NIRS. With spectral analysis based on wavelet transform, five frequency intervals were identified (I, 0.005-0.02Hz, II, 0.02-0.06Hz, III, 0.06-0.15Hz, IV, 0.15-0.40Hz and V, 0.40-2.0Hz) corresponding to endothelial related metabolic, neurogenic, myogenic, respiratory and cardiac activities, respectively. The results showed that the amplitude of the [HbO(2)] and [Hb] component in intervals I, II and III for persons with SCI was significantly lower during the resting conditions than that for normal subjects (p<0.05). During the post-loading period, the response of [HbO(2)] and [Hb] oscillatory activities in intervals II and III were significantly lower in the tissue over the sacrum for persons with SCI than that for normal subjects (p<0.05). Also significant negative correlation was found between oscillatory activities and Waterlow scale in persons with SCI. The results indicated that the low oscillatory activities might be related to early tissue injury in persons with SCI.

Expression of vascular endothelial growth factor and matrix metalloproteinase-9 in sacral chordoma.

Sacral chordoma is a vessel-rich and infiltrative tumor, but the fundamental knowledge of its biological behavior remains unknown. This study was designed to investigate the expression levels and contributions of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in the angiogenesis and recurrence of sacral chordoma and their correlations. An immunohistochemical method was used to investigate the expression of VEGF, MMP-9, and microvascular density (MVD) in 36 patients with sacral chordoma. Their differences in expressions were statistically analyzed and their correlations with angiogenesis and recurrence were evaluated. The mean MVD of sacral chordomas was significantly higher than that of the adjacent normal tissues (P = 0.033). Immunoreactivity for VEGF and MMP-9 was significantly higher in sacral chordoma tissues than in adjacent normal tissues (P = 0.008, P = 0.005). The mean MVD of VEGF and MMP-9 were statistically higher in positive group than in negative group (P = 0.015, P = 0.004), respectively . Moreover, a significant correlation was found between the VEGF and MMP-9 (P = 0.002). The log-rank test revealed that continuous disease-free survival time (CDFS) was significantly shorter in the MMP-9-positive group than in the MMP-9-negative group (P = 0.019), but the difference in the VEGF-positive group and the VEGF-negative group was not statistically significant (P = 0.938). Our data suggest that VEGF and MMP-9 might act with a synergistic effect and can positively regulate the angiogenesis in sacral chordoma. Positive expression of MMP-9 might indicate the local recurrence of sacral chordoma. The result suggests that some specific drugs which inhibit VEGF, MMP-9, or their receptors may have a good therapeutic effect for sacral chordoma.

Control of presacral venous bleeding with helical tacks on PTFE pledgets combined with pelvic packing.

Persistent and torrential bleeding from presacral veins is an uncommon complication during rectal resection. Control of bleeding is often difficult. We report an effective technique for controlling sacral bleeding using endoscopic helical tackers applied over pledgets of expanded polytetrafluoroethylene.

[Sacral dural arteriovenous fistula: report of 4 cases].

Spinal dural arteriovenous fistula (SDAVF) in the sacral region is relatively rare and remains difficult to diagnose because of the uncommon origin of its feeder. It also has higher incidence of recurrence than usual thoraco-lumbar lesion and needs subsequent treatment. We reviewed 51 cases of SDAVF over the past 10 years. Especially in patients with sacral lesion, clinical features and the findings on spinal angiography were analyzed. Four patients (7.8%) had SDAVF in the sacral region. In all cases, SDAVF were supplied by the lateral sacral artery. Multiple feeders were observed in 3 (75%) out of 4 patients and 2 patients (50%) had multiple fistulas. Endovascular embolizations were performed in all patients, and neurological symptoms were improved in two patients (50%) and the other two were stabilized (50%). There was no recurrence during a follow-up period of 3 months to 8 years. We should keep in mind that SDAVF in the sacral region can have multiple shunts and feeders derived from the lateral sacral artery.

Endovascular treatment of a sacral dural arteriovenous fistula.

Spinal dural arteriovenous fistula (SDAVF) is a rare pathological communication between arterial and venous vessels within the spinal dural sheath. Clinical presentation includes progressive spinal cord symptoms including gait difficulty, sensory disturbances, changes in bowel or bladder function, and sexual dysfunction. These fistulas are most often present in the thoracolumbar region. Diagnoses of SDVAFs are commonly missed, possibly due to the low index of suspicion, non-specific symptoms and challenging imaging. In this case report, we describe a rare presentation of a sacral SDAVF which was detected by collective efforts between endovascular neurosurgery and interventional radiology. We outline the diagnostic and imaging challenges we faced to discover the fistula. In particular, mechanical pump injection instead of hand injection during angiography was required to reveal the fistula. Following identification, the fistula was successfully treated endovascularly by using onyx (ethylene vinyl alcohol glue), a less invasive alternative to surgical intervention.

The fibrinogen levels on admission is a predictive marker of the contrast extravasation on enhanced computed tomography in sacral fracture.

ABSTRACT: Sacral fracture is the most frequent posterior injury among unstable pelvic ring fractures and is prone to massive hemorrhage and hemodynamic instability. Contrast extravasation (CE) on computed tomography (CT) is widely used as an indicator of significant arterial bleeding. However, while CE is effective to detect significant arterial bleeding but negative result cannot completely rule out massive bleeding. Therefore, additional factors help to compensate CE for the prediction of early hemodynamically unstable condition.We evaluated the risk factors that predict CE on enhanced computed CT in patients with sacral fractures. Patients were classified into 2 groups: CE positive on enhanced CT of the pelvis [CE(+)] and CE negative [CE(-)]. We compared age, sex, injury severity score (ISS), systolic blood pressure (sBP), type of sacral fracture based on Denis classification, platelet (PLT), base excess, lactate, prothrombin time-international normalized ratio, hemoglobin (Hb), activated partial thromboplastin time, D-dimer, and fibrinogen between the 2 groups.A total of 82 patients were treated for sacral fracture, of whom 69 patients were enrolled. There were 17 patients (10 men and 7 women) in CE(+) and 52 patients (28 men and 24 women) in CE(-). Age, ISS, and blood transfusion within 24 hours were significantly higher in the CE(+) group than in the CE(-) group (P = .023, P < .001, P < .001). sBP, Hb, PLT, fibrinogen were significantly lower in the CE(+) group than in the CE(-) group (P < .001, P < .001, P < .001, P < .001). D-dimer and lactate were higher in the CE(+) group than in the CE(-) group (P = .036, P < .001) with significant differences. On multivariate analysis, the level of fibrinogen was an independent predictor of CE(+). The area under the curve value for fibrinogen was 0.88, and the optimal cut-off value for prediction was 199 mg/dL.The fibrinogen levels on admission can predict contrast extravasation on enhanced CT in patients with sacral fractures. The optimal cut-off value of fibrinogen for CE(+) prediction in sacral fracture was 199 mg/dL. The use of fibrinogen to predict CE(+) could lead to prompt and effective treatment of active arterial hemorrhage in sacral fracture.

Embolization of a type 2 endoleak through catheterization of a hypogastric branched stent-graft.

In contrast to internal iliac artery (IIA) occlusion, the use of branch stent-graft (BSG) has been developed as an efficient adjunct in preserving pelvic blood flow. However, the risk of post-procedural type 2 endoleak (EL) remains. We present the case of an 80-year-old man with a juxtarenal aneurysm extending to both common and IIA. The patient was treated with a fenestrated device and a left BSG after embolization of the right IIA branches. At 6 months, the persistence of a type 2 EL associated with aneurysm growth mandated EL embolization through the BSG with a good result. Technical issues are discussed.