Design and operation problems related to water curtain system forunderground water-sealed oil storage caverns

The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.

Intrahepatic portal venous systems in adult patients with cavernous transformation of portal vein: Imaging features and a new classification

Background: Cavernous transformation of the portal vein(CTPV) due to portal vein obstruction is a rare vascular anomaly defined as the formation of multiple collateral vessels in the hepatic hilum. This study aimed to investigate the imaging features of intrahepatic portal vein in adult patients with CTPV and establish the relationship between the manifestations of intrahepatic portal vein and the progression of CTPV. Methods: We retrospectively analyzed 14 CTPV patients in Beijing Tsinghua Changgung Hospital. All patients underwent both direct portal venography(DPV) and computed tomography angiography(CTA) to reveal the manifestations of the portal venous system. The vessels measured included the left portal vein(LPV), right portal vein(RPV), main portal vein(MPV) and the portal vein bifurcation(PVB). Results: Nine males and 5 females, with a median age of 40.5 years, were included in the study. No significant difference was found in the diameters of the LPV or RPV measured by DPV and CTA. The visualization in terms of LPV, RPV and PVB measured by DPV was higher than that by CTA. There was a significant association between LPV/RPV and PVB/MPV in term of visibility revealed with DPV( P = 0.01), while this association was not observed with CTA. According to the imaging features of the portal vein measured by DPV, CTPV was classified into three categories to facilitate the diagnosis and treatment. Conclusions: DPV was more accurate than CTA for revealing the course of the intrahepatic portal vein in patients with CTPV. The classification of CTPV, that originated from the imaging features of the portal vein revealed by DPV, may provide a new perspective for the diagnosis and treatment of CTPV.

Resection of Intracranial Giant Cavernous Malformation: Case Report and Literature Review

Cerebral cavernous malformations are a rare and congenital vascular malformation that can present as a challenge in neurosurgical management. The term “giant cerebral cavernous malformations” still does not have a clear definition in the literature, with a wide variety of results. It is known, however, that there is an association between the size of the cavernoma and postoperative sequelae, especially in those with a size greater than 3 cm in its largest diameter. We present a case report of resection of a giant brain cavernoma measuring approximately 8 cm in its largest diameter, emphasizing on clinical presentation, diagnoses and postoperative evolution. Additionally, we performed a comprehensive review of the existing literature on the subject, addressing the epidemiology, pathophysiology, diagnostic methods, treatment options, and prognosis associated with this condition.

Global stability coefficient of large underground caverns under static loading and earthquake wave condition

Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.

Large-Scale Carbon Dioxide Storage in Salt Caverns:Evaluation of Operation,Safety,and Potential in China

Underground salt cavern CO_(2) storage(SCCS)offers the dual benefits of enabling extensive CO_(2) storage and facilitating the utilization of CO_(2) resources while contributing the regulation of the carbon market.Its economic and operational advantages over traditional carbon capture,utilization,and storage(CCUS)projects make SCCS a more cost-effective and flexible option.Despite the widespread use of salt caverns for storing various substances,differences exist between SCCS and traditional salt cavern energy storage in terms of gas-tightness,carbon injection,brine extraction control,long-term carbon storage stability,and site selection criteria.These distinctions stem from the unique phase change characteristics of CO_(2) and the application scenarios of SCCS.Therefore,targeted and forward-looking scientific research on SCCS is imperative.This paper introduces the implementation principles and application scenarios of SCCS,emphasizing its connections with carbon emissions,carbon utilization,and renewable energy peak shaving.It delves into the operational characteristics and economic advantages of SCCS compared with other CCUS methods,and addresses associated scientific challenges.In this paper,we establish a pressure equation for carbon injection and brine extraction,that considers the phase change characteristics of CO_(2),and we analyze the pressure during carbon injection.By comparing the viscosities of CO_(2) and other gases,SCCS’s excellent sealing performance is demonstrated.Building on this,we develop a long-term stability evaluation model and associated indices,which analyze the impact of the injection speed and minimum operating pressure on stability.Field countermeasures to ensure stability are proposed.Site selection criteria for SCCS are established,preliminary salt mine sites suitable for SCCS are identified in China,and an initial estimate of achievable carbon storage scale in China is made at over 51.8-77.7 million tons,utilizing only 20%-30%volume of abandoned salt caverns.This paper addresses key scientific and engineering challenges facing SCCS and determines crucial technical parameters,such as the operating pressure,burial depth,and storage scale,and it offers essential guidance for implementing SCCS projects in China.

Comparative analysis of thermodynamic and mechanical responses between underground hydrogen storage and compressed air energy storage in lined rock caverns

Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage processes.This study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock caverns.Gas thermodynamic responses are validated using additional simulations and the field test data.Temperature and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation modes.Hydrogen reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and pressure.Unlike steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing layer.In CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same areas.Our present research can provide references for the selection of energy storage methods.

Endovascular treatment of direct carotid cavernous fistula resulting from rupture of intracavernous carotid aneurysm: A case report

BACKGROUND Direct carotid cavernous fistulas(CCFs)are typically the result of a severe traumatic brain injury.High-flow arteriovenous shunts secondary to rupture of an intracavernous aneurysm,resulting in direct CCFs,are rare.The use of a pipeline embolization device in conjunction with coils and Onyx glue for treatment of direct high-flow CCF resulting from ruptured cavernous carotid artery aneurysm in a clinical setting is not well documented.CASE SUMMARY A 58-year-old woman presented to our department with symptoms of blepharoptosis and intracranial bruits for 1 wk.During physical examination,there was right eye exophthalmos and ocular motor palsy.The rest of the neurological examination was clear.Notably,the patient had no history of head injury.The patient was treated with a pipeline embolization device in the ipsilateral internal carotid artery across the fistula.Coils and Onyx were placed through the femoral venous route,followed by placement of the pipeline embolization device with assistance from a balloon-coiling technique.No intraoperative or perioperative complications occurred.Preoperative symptoms of bulbar hyperemia and bruits subsided immediately after the operation.CONCLUSION Pipeline embolization device in conjunction with coiling and Onyx may be a safe and effective approach for direct CCFs.

Endoscopic ultrasound-guided lauromacrogol injection for treatment of colorectal cavernous hemangioma:Two case reports

BACKGROUND Colorectal cavernous hemangioma is a rare vascular malformation resulting in recurrent lower gastrointestinal hemorrhage,and can be misinterpreted as colitis.Surgical resection is currently the mainstay of treatment,with an emphasis on sphincter preservation.CASE SUMMARY We present details of two young patients with a history of persistent hematochezia diagnosed with colorectal cavernous hemangioma by endoscopic ultrasound(EUS).Cavernous hemangioma was relieved by several EUS-guided lauromacrogol injections and the patients achieved favorable clinical prognosis.CONCLUSION Multiple sequential EUS-guided injections of lauromacrogol is a safe,effective,cost-efficient,and minimally invasive alternative for colorectal cavernous hemangioma.

A preliminary site selection system for underground hydrogen storage in salt caverns and its application in Pingdingshan,China

Large‐scale underground hydrogen storage(UHS)provides a promising method for increasing the role of hydrogen in the process of carbon neutrality and energy transition.Of all the existing storage deposits,salt caverns are recognized as ideal sites for pure hydrogen storage.Evaluation and optimization of site selection for hydrogen storage facilities in salt caverns have become significant issues.In this article,the software CiteSpace is used to analyze and filter hot topics in published research.Based on a detailed classification and analysis,a“four‐factor”model for the site selection of salt cavern hydrogen storage is proposed,encompassing the dynamic demands of hydrogen energy,geological,hydrological,and ground factors of salt mines.Subsequently,20 basic indicators for comprehensive suitability grading of the target site were screened using the analytic hierarchy process and expert survey methods were adopted,which provided a preliminary site selection system for salt cavern hydrogen storage.Ultimately,the developed system was applied for the evaluation of salt cavern hydrogen storage sites in the salt mines of Pingdingshan City,Henan Province,thereby confirming its rationality and effectiveness.This research provides a feasible method and theoretical basis for the site selection of UHS in salt caverns in China.

Intermittent melena and refractory anemia due to jejunal cavernous lymphangioma:A case report

BACKGROUND Lymphangiomas in the gastrointestinal tract are extremely rare in adults.As a benign lesion,small intestine lymphangiomas often remain asymptomatic and pose challenges for definitive diagnosis.However,lymphangiomas can give rise to complications such as abdominal pain,bleeding,volvulus,and intussusception.Here,we report a case of jejunal cavernous lymphangioma that presented with intermittent melena and refractory anemia in a male adult.CASE SUMMARY A 66-year-old man presented with intermittent melena,fatigue and refractory anemia nine months prior.Esophagogastroduodenoscopy and colonoscopy were performed many times and revealed no apparent bleeding.Conservative management,including transfusion,hemostasis,gastric acid secretion inhibition and symptomatic treatment,was performed,but the lesions tended to recur shortly after surgery.Ultimately,the patient underwent capsule endoscopy,which revealed a more than 10 cm lesion accompanied by active bleeding.After singleballoon enteroscopy and biopsy,a diagnosis of jejunal cavernous lymphangioma was confirmed,and the patient underwent surgical resection.No complications or recurrences were observed postoperatively.CONCLUSION Jejunal cavernous lymphangioma should be considered a cause of obscure gastrointestinal bleeding.Capsule endoscopy and single-balloon enteroscopy can facilitate diagnosis.Surgical resection is an effective management method.

Giant cavernous aneurysms occluded by aneurysmal thrombosis,calcification,parent artery occlusion:A case report and review of literature

BACKGROUND Patients with giant intracranial aneurysms(GIAs)are at a high risk of rupture,morbidity,and mortality even after surgical or endovascular treatment.We described a case of a spontaneously occluded GIA secondary to gradual growth of the GIA,continuously progressed aneurysmal thrombosis,complete aneurysmal calcification and complete occlusion of the parent artery-the right internal carotid artery(RICA).CASE SUMMARY A 72-year-old female patient complained of sudden pain in her right eye upon admission to our hospital.She had been diagnosed with a GIA[30 mm(axial)×38 mm(coronal)×28 mm(sagittal)]containing an aneurysmal thrombus located in the cavernous sinus segment of RICA diagnosed by magnetic resonance imaging(MRI),enhanced MRI,and magnetic resonance angiography more than 14 years ago.Later,with slow growth of the cavernous carotid GIA,aneurysmal thrombosis progressed continuously,spontaneous occlusion of the RICA,complete aneurysmal calcification,and occlusion of the GIA occurred gradually.She had no history of subarachnoid hemorrhage but missed the chance for endovascular therapy at an early stage.As a result,she was left with severe permanent sequelae from the injuries to the right cranial nerves Ⅱ,Ⅲ,Ⅳ,V1/V2,and Ⅴ.CONCLUSION The risk of rupture of the cavernous carotid GIAs was relatively low and possibly further be reduced by the stasis flow and spontaneous occlusion of the parent artery internal carotid artery(ICA)induced by the mass effect of the cavernous carotid GIAs and the extremely rare aneurysmal calcification.However,nowadays,it is advisable to recommend early endovascular treatment for the cavernous carotid GIAs to prevent injuries to the surrounding intracranial nerves and occlusion of the ICA,mainly caused by the mass effect of the cavernous carotid GIAs.

CT and MRI Findings of Intracranial Cavernous Hemangioma Malformation

Objective:To investigate the computed tomography(CT)and magnetic resonance imaging(MRI)features of cavernous hemangioma malformation(CHM)to enhance diagnostic accuracy.Methods:The CT and MRI findings and clinical information of 23 patients with CHM were retrospectively analyzed.Results:CT examinations were conducted in 7 cases,while MRI was utilized in 23 cases.Additionally,SWI was employed in 5 cases and enhanced imaging techniques were applied in 14 cases.Among the observed lesions,20 cases presented with a singular lesion,whereas 3 cases exhibited multiple lesions.The lesions were located in 8 frontal lobes,6 cerebellums,2 brainstems,6 temporal lobes,1 basal ganglia,3 parieto-occipital lobes,and 2 thalamus regions.The nodules appeared as quasi-circular lesions with clear or well-defined boundaries.They presented as isodense lesions on CT scans,with one lesion showing peritumoral edema.On MRI,T1-weighted imaging(T1WI)demonstrated isointense signals,while T2-weighted imaging(T2WI)showed isointense and hyperintense signals.Additionally,10 lesions exhibited a low signal ring on T2WI.Diffusion-weighted imaging(DWI)revealed nodular or isointense low signals,while susceptibility-weighted imaging(SWI)displayed enlarged areas of low signal.Fourteen lesions underwent contrast-enhanced scanning,with 2 lesions showing no obvious enhancement,1 lesion demonstrating mild to moderate enhancement,and 11 lesions exhibiting significant enhancement.Notably,6 of these enhanced lesions were surrounded by small blood vessels.Conclusion:Cavernous hemangioma malformation is more commonly found in individual cases.CT alone lacks specificity,making it prone to misdiagnosis.A more comprehensive evaluation of cavernous hemangioma malformation can be achieved through a combination of MRI,DWI,SWI,and enhanced examination,providing valuable references for clinical assessment.

Key issues in water sealing performance of underground oil storage caverns: Advances and perspectives

Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safety(WSS),water curtain performance,and prediction and control of water inflow.This paper reviews the progress of above four key issues on water sealing performances.First,the permeability of an FRM is the basis of water sealing performance,and several commonly used permeability test methods and spatial variation characteristics of permeability are outlined.Second,the current water sealing criteria are compared,and the evaluation methods of WSS are summarized.Third,the design parameters and efficiency evaluation of water curtain systems(WCSs)are introduced.The water inflow of oil storage caverns(OSCs)can reflect the water sealing effect,and the prediction methods and control measures of water inflow are also summarized.Finally,the advantages and disadvantages of the current research are discussed,and the potential research directions are pointed out,such as optimization of water sealing criteria and FRM model,quantitative evaluation of WCS efficiency,accurate prediction of water inflow,and improvement of grouting technology.

Rock mass response for lined rock caverns subjected to high internal gas pressure

The storage of hydrogen gas in underground lined rock caverns(LRCs)enables the implementation of the first fossil-free steelmaking process to meet the large demand for crude steel.Predicting the response of rock mass is important to ensure that gas leakage due to rupture of the steel lining does not occur.Analytical and numerical models can be used to estimate the rock mass response to high internal pressure;however,the fitness of these models under different in situ stress conditions and cavern shapes has not been studied.In this paper,the suitability of analytical and numerical models to estimate the maximum cavern wall tangential strain under high internal pressure is studied.The analytical model is derived in detail and finite element(FE)models considering both two-dimensional(2D)and three-dimensional(3D)geometries are presented.These models are verified with field measurements from the LRC in Skallen,southwestern Sweden.The analytical model is inexpensive to implement and gives good results for isotropic in situ stress conditions and large cavern heights.For the case of anisotropic horizontal in situ stresses,as the conditions in Skallen,the 3D FE model is the best approach.

Study on cavern evolution and performance of three mixers in agitation of yield-pseudoplastic fluids

The hydrodynamic performance of three mixers single shaft central mixer(SSC), single shaft off-centred mixer(SSO), dual shaft off-centred mixer(DSO), was investigated in the mixing of yield-pseudoplastic fluids(xanthan gum solutions) in the laminar regime. To explore and determine the efficiency of three mixers, both numerical and experimental approaches were adopted. The fluid rheology was described by the Herschel–Bulkley rheological model. Computational fluid dynamics was employed to simulate the apparent viscosity distribution, mixing time, and the flow pattern inside the stirred tank. The developed model was validated through experimentally measured torque. The influence mechanism of the rotational speed and fluid rheology on the cavern evolution was explored deeply. The performances of three mixers in this work were compared at the constant power input and fluid rheology with respect to the flow pattern, mixing time, and mixing efficiency. The results verify that the faster the rotating speed, the greater influence of the fluid rheology on the cavern evolution, and the more uniform apparent viscosity distribution. Moreover, the mixing time decreases continuously as the increasing power consumption per unit volume, and the dimensionless mixing time of DSO mixer was nearly 42.8% and 6.1% shorter than that of SSC and SCO mixer at the same Reynolds number, respectively. According to the mixing efficiency criteria, these data also revealed that DSO was more efficient than SSC and SSO.

Spalling failure of deep hard rock caverns

Spalling is a typical brittle failure phenomenon of hard rock in deep caverns under high geostress.In this study,key issues are systematically studied concerning the spalling failure of deep hard rock caverns.First,the prismatic rock specimens with small thicknesses(i.e.width×thickness×height:20 mm×50 mm×100 mm)are employed in our tests which not only successfully simulate the spalling failure of hard rock in the laboratory but also obtain a reasonable spalling strength similar to that of the rock mass.Then,a series of spalling experiments is carried out to investigate the mechanism of spalling failure of deep hard rock caverns.Our results show that the intermediate principal stress,weak dynamic disturbances,and rock microstructure have significant effects on the spalling failure.The spalling strength is approximately(0.3–0.8)UCS,where UCS is the uniaxial compressive strength of the cylindrical rock sample with a diameter of around 50 mm.The spalling strength increases first and then decreases with increasing intermediate principal stress.Moreover,an empirical spalling strength criterion and a numerical method of spalling failure are proposed.This numerical method can not only simulate the spalling failure zone formed by tangential compressive stress concentration after excavation under different intermediate principal stresses,but also successfully simulate the failure transition from tensile mode to shear mode associated with confinement change in deep hard rock caverns.Furthermore,an acoustic emission-based early warning method using neural network is proposed to predict the spalling failure.Finally,a technical roadmap for preventing and controlling spalling failure of deep hard rock caverns is presented after summarizing the successful experiences in a typical engineering case.

Application of transmesenteric vein extrahepatic portosystemic shunt in treatment of symptomatic portal hypertension with cavernous transformation of portal vein

Purpose:To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt(TmEPS)for the treatment of cavernous transformation of the portal vein(CTPV).Materials and methods:The clinical data of 20 patients with CTPV who underwent TmEPS between December 2020and January 2022 at Henan Provincial People’s Hospital were retrospectively collected.The superior mesenteric vein(SMV)trunk was patent or partially occluded in these patients.An extrahepatic portosystemic shunt between the inferior vena cava and the SMV was established using a stent graft through an infraumbilical median longitudinal mini-laparotomy.The technical success,efficacy,and complication rates were evaluated,and the preand postoperative SMV pressures were compared.Patients’clinical outcomes and shunt patency were assessed.Results:TmEPS was successfully performed in 20 patients.The initial puncture success rate of the balloon-assisted puncture technique is 95%.The mean SMV pressure decreased from 29.1±2.9 mmHg to 15.6±3.3 mmHg(p<0.001).All symptoms of portal hypertension resolved.No fatal procedural complications occurred.During the follow-up period,hepatic encephalopathy occurred in two patients.The remaining patients remained asymptomatic.All shunts were patent.Conclusions:TmEPS is a feasible,safe,and effective treatment option for patients with CTPV.

Determination of convergence of underground gas storage caverns using non-invasive methodology based on land surface subsidence measurement

Undergroundgas storage caverns aremonitoredfor environmental safety in termsof equipmentandpotential emissions,particularly methane emissions from the underground and above-ground parts of the storage facility.Periodical measurements of land surface deformations and costly echometric measurements of convergence of individual storage facilities are carried out.The aims of environmental monitoring are:(1)to eliminate potential hazards in the shortest time,(2)assess the overall impact of intensive operation of storage facilities on the environment,(3)developmonitoringmethods relevant to environmental protection,and(4)take actions in case of failure.The paper presents a solution to the problem of determination of the convergence of underground caverns in a salt rock mass based on the results of land surface subsidence measurements carried out using the Gauss-Markov equalization algorithm.Themethod makes it possible for ongoing control of cavern volume convergence after each subsidence measurement on the ground surface and determining the actual impact of the use frequency(injection-mediumconsumption)on the convergence in time.The presentedmethodology is universal and verified on caverns located in a salt rockmass.The Gauss-Markov inversion model is the first used in this area,hence its application is significant.

Retroperitoneal cavernous hemangioma misdiagnosed as lymphatic cyst:A case report and review of the literature

BACKGROUND Primary abdominal and retroperitoneal cavernous hemangioma is a vascular tumor and rarely seen in the clinic.Due to the lack of specific imaging features,retroperitoneal cavernous hemangioma cannot be diagnosed accurately.Some symptoms may develop with the enlargement of lesion volume or the occurrence of complications such as rupture or oppression.We report here a special case who was admitted with chronic abdominal pain.Admission examination suggested a retroperitoneal lymphatic duct cyst.Laparoscopic resection of the retroperitoneal mass was performed,and histological examination confirmed retroperitoneal cavernous hemangioma.CASE SUMMARY The patient was a 43-year-old Tibetan woman with intermittent left lower abdominal pain and discomfort 3 years ago.Ultrasonography revealed a cystic mass in the retroperitoneum with clear boundaries,internal septa,and no blood flow signal.Computed tomography(CT)and magnetic resonance imaging(MRI)showed an irregular space-occupying mass in the retroperitoneum,and retroperitoneal lymphatic cyst was considered.Plain CT scanning showed multiple cystlike hypo-intense shadows in the retroperitoneum,partially fused into a mass,and no obvious enhancement was found on enhanced scanning.MRI showed multiple irregular clump-like long T1 and long T2 signal shadows above the pancreas,within which linear short T2 signal shadows were seen.Diffusionweighted imaging sequence showed hypo-signal shadows,without obvious enhancement on enhanced scanning.Ultrasound,CT,and MRI all suggested the possibility of retroperitoneal lymphatic cyst.However,the patient was finally diagnosed with retroperitoneal cavernous hemangioma by pathological examination.CONCLUSION Retroperitoneal cavernous hemangioma is a benign lesion,and it is difficult to make a diagnosis preoperatively.Surgical resection may be the only treatment,which not only allows histopathological confirmation as a diagnostic purpose and excludes any risk of malignancy,but also avoids invasion of adjacent tissues,oppression,and other complications as a therapeutic goal.

High-flow priapism due to bilateral cavernous artery fistulas treated by unilateral embolization:A case report

BACKGROUND High flow priapism(HFP)is a rare type of priapism.Perineal trauma is the most common cause of HFP.Trauma-induced penile artery injury may lead to an arterial-cavernosal fistula,whereas persistent irregular arterial blood flow entering the corpora cavernosum can cause a persistent penile erection.The routine treatment of HFP focuses on addressing the abnormal penile erectile status and avoiding post-treatment erectile dysfunction.Interventional embolization is an important therapeutic modality for HFP,and bilateral embolization therapy is currently the most commonly used technique for patients with bilateral cavernous artery fistulas;however,unilateral embolization therapy has yet to be reported.CASE SUMMARY Herein,we report of the case of a 26-year-old Chinese male who presented with a persistent abnormal erection for 12 h after perineal impact injury.Medical history,cavernous arterial blood gas analysis and radiological examinations led to a diagnosis of HFP caused by bilateral cavernous artery fistulas.We performed routine conservative treatment(compression therapy and ice application)for the patient after admission;however,10 d later,his symptoms had not been relieved.After completion of the preoperative workup,right(severe side)selective perineal artery embolization was performed;the left cavernous artery fistula was left untreated.After postoperative continuation of conservative treatment for 72 h,the patient experienced complete penile thinning.The patient had no symptoms of erectile dysfunction over a follow-up period of 12 mo.CONCLUSION Compared with bilateral cavernous artery fistula embolization,we believe that unilateral cavernous artery fistula embolization can achieve positive clinical efficacy and reduce the risk of postoperative erectile dysfunction secondary to penile ischemia.