Subspecialty radiology and surgery

The Master said: "Yu! Shall I teach you the meaning of knowledge?When you know a thing to recognize that you know it; and when you do not, to know that you do not know

Limitations of multimodality imaging in the diagnosis of pannus formation in prosthetic aortic valve and review of the literature

Pannus formation is a rare complication and occurs almost exclusively in mechanical prosthetic valves.It consists of fibrous tissue that covers the surface of the prosthesis either concentrically or eccentrically,resulting in valve dysfunction.The pathophysiology seems to be associated to a chronic inflammatory process that explains the late and insidious clinical presentation.This diagnosis should be considered in patients with high transvalvular gradients on transthoracic echo,and workup should be completed with fluoroscopy and transesophageal echocardiography.Treatment is always surgical and recurrence is rare.We present a case of pannus formation in a prosthetic aortic valve and a review of the literature regarding this disorder.

Outcome of transarterial chemoembolization in patients with inoperable hepatocellular carcinoma eligible for radiofrequency ablation

AIM： To evaluate the outcome of transarterial chemoembolization （TACE）in patients with unresectable hepatocellular cardnoma （HCC） 〈5 cm in diameter eligible for radiofrequency ablation （RFA）. METHODS： The treatment-related mortality, morbidity, long-term survival, and prognostic factors of HCC patients who had TACE and fulfilled the present inclusion criteria for RFA were evaluated. RESULTS： Of the 748 patients treated with TACE between January 1990 and December 2002, 114 patients were also eligible for RFA. The treatment-related mortality and morbidity were 1% and 19%, respectively. Survival at 1, 3, and 5 years was 80%, 43%, and 23%, respectively. Older age and a high albumin level were associated with a better survival, whereas a high α-fetoprotein level （AFP） and the size of the largest tumor 〉3 cm in diameter were adverse prognostic factors in multivariate analysis. CONCLUSION： The morbidity, mortality, and survival data after TACE for small HCCs eligible for RFA are comparable to those reported after RFA in the literature. Our data suggest the need for a randomized comparison of the two treatment modalities for small HCCs.

Does vitamin C have the ability to augment the therapeutic effect of bone marrow-derived mesenchymal stem cells on spinal cord injury？

Methylprednisolone（MP） is currently the only drug confirmed to exhibit a neuroprotective effect on acute spinal cord injury（SCI）. Vitamin C（VC） is a natural water-soluble antioxidant that exerts neuroprotective effects through eliminating free radical damage to nerve cells. Bone marrow mesenchymal stem cells（BMMSCs）, as multipotent stem cells, are promising candidates in SCI repair. To evaluate the therapeutic effects of MP, VC and BMMSCs on traumatic SCI, 80 adult male rats were randomly divided into seven groups： control, SCI（SCI induction by weight-drop method）, MP（SCI induction, followed by administration of 30 mg/kg MP via the tail vein, once every other 6 hours, for five times）, VC（SCI induction, followed by intraperitoneal administration of 100 mg/kg VC once a day, for 28 days）, MP ＋ VC（SCI induction, followed by administration of MP and VC as the former）, BMMSCs（SCI induction, followed by injection of 3 × 10~6 BMMSCs at the injury site）, and BMMSCs ＋ VC（SCI induction, followed by BMMSCs injection and VC administration as the former）. Locomotor recovery was assessed using the Basso Mouse Scale. Injured spinal cord tissue was evaluated using hematoxylin-eosin staining and immunohistochemical staining. Expression of transforming growth factor-beta, tumor necrosis factor-alpha, and matrix metalloproteinase-2 genes was determined using real-time quantitative PCR. BMMSCs intervention better promoted recovery of nerve function of rats with SCI, mitigated nerve cell damage, and decreased expression of transforming growth factor-beta, tumor necrosis factor-alpha, and matrix metalloproteinase-2 genes than MP and/or VC. More importantly, BMMSCs in combination with VC induced more obvious improvements. These results suggest that VC can enhance the neuroprotective effects of BMMSCs against SCI.

Fatigue Performance of Fabrics of Stent-Grafts Supported with Z-Stents vs. Ringed Stents

Stent-grafts were commercialized rapidly and gained a broad clinical acceptance over the past two decades. However,relatively more recent recognition of particular stent-graft design shortcomings have been identified which need to be addressed. It appears that various stent-graft designs may be more or less resistant to metal fatigue and /or fabric abrasions which can lead to type III and type IV endoleaks over the long term. Therefore,it is necessary to investigate the fatigue performance of the most common stentgraft designs: Z-stents and ringed stents,in a long-term in vitro fatigue simulation environment. This paper aimed to analyze nondestructively( gross observations) and destructively( fabric characteristics,mechanical and chemical properties) in order to put forward suggestions to improve the fabric and stent characteristics that may prevent type III and IV endoleaks. The fabric supported with ringed stent-grafts remained nearly completely intact after 168h. However, the fabric supported with Z-stents demonstrated significant damage. Fabric characteristics and tensile strength of the fibers did not present a significant difference between the control and fatigue simulated specimens. The crystallinity declined for both specimens. The fatigue performance of fabrics supported with ringed stents appears to be superior to that supported with Z-stents. The potential for a dynamic and destructive interaction between the apices of Z-stents which can lead to fraying and /or tearing of the graft fabric must be addressed in future designs.

Testicular vascularization at two locations in relation to hormonal levels,and pixel echotexture in bulls at different ages

Objective:To assess the hemodynamic changes that occurred in the main testicular artery at two different locations such as supra and marginal ones in bulls at three different ages.Methods:Eighteen Baladi bulls were divided according to their age into three different age groups:1 year[n=6;groupⅠwith bodyweight(380±10)kg],3 years[n=6;groupⅡwith bodyweight(570±10)kg],and 6 years old[n=6;groupⅢwith bodyweight(650±10)kg]Baladi bulls.Circumference of the scrotum,thickness of the mediastinum,testicular dimensions,vascularity,and hormonal levels were measured.Testicular hemodynamics were assessed by Doppler ultrasound scanning.Results:Testicular width,length,and volume were significantly different among the three age groups,with the highest in bulls of groupⅢ(P<0.05).The bulls in groupⅢhad significantly higher mediastinal line thickness and scrotal circumference than groupⅠ(P<0.05),but there was no significant difference between groupⅡand groupⅢ.Bulls in groupⅡshowed a decline in Doppler indices(resistance and pulsatility indexes)at both testicular branches compared to the other two groups(P<0.05).Supra and marginal end diastolic velocities in the three age groups were significantly different,with the highest in groupⅡ(P<0.05).Time average velocity(cm/s)was significantly elevated in groupⅡcompared to the other two groups(P<0.05).Both testicular echotextures were significantly decreased in groupⅡ(P<0.05).Estradiol and nitric oxide metabolites were significantly high in groupⅡcompared to the other two groups(P<0.05).Meanwhile,the level of plasma testosterone was maximum in groupⅢ(P<0.05).Positive correlations were found between supratesticular artery resistance and pulsatility indexes(r=0.81;P<0.001),while both resistance and pulsatility indexes had correlated negative with estradiol(r=-0.71 and r=-0.91;P<0.001),and nitric oxide metabolites(r=-0.92 and r=-0.72;P<0.001).Conclusions:Three-year old Baladi bull has the lesser Doppler indices with lesser echotexture and greater nitric oxide with estradiol concentrations,which directs a significant ability for the thermoregulation process.These parameters will help in breeding selection.

Exploring the Feasibility of a New Low Cost Intra-Dermal Pre &Post Exposure Rabies Prophylaxis Protocol in Domestic Bovine in Jawali Veterinary Hospital, District Kangra, Himachal Pradesh, India

Cattle are the backbone of household economy in rural areas of India and many of them die after bites by potentially rabid dogs, despite being given currently recommended five shots of intramuscular (IM) rabies vaccination as Post Exposure Prophylaxis (PEP). In 2016, seven of 21 bovine bitten by rabid dogs given IM rabies vaccination died due to rabies in Shimla Municipality. This scenario prompted the authors to look for a suitable protocol, based on human studies, to save animals. We tested various schedules of IDRV in bovine and found that a schedule of 0.2 ml given in middle 1/3rd of neck on day 0, 3, 7, 14 and 28 along with local wound infiltration of eRIG is sufficiently immunogenic and life saving in all of them, even if bitten by lab confirmed rabid dogs/mongoose as tested by CRI. Rabivac Vet, a Cell Culture Rabies Vaccine, available as 1 ml per vial was used off level for IDRV. While injecting the vaccine, a raised papule of ≥1 cm will appear slowly causing a peau d’orange appearance. All 60 bovine serum samples tested by RFFIT after IDRV, had titers more than 0.5 IU/ml on day 14. Thereafter, a total of 150 animals were given five doses of IDRV as PEP, with or without RIG, after their exposure to clinically or lab confirmed rabid dogs/mongoose and all survived for more than a year. Serum samples from 15 animals bitten by lab confirmed rabid dogs/mongoose were collected on day 14 and tested for RVNA by RFFIT from NIMHANS Bangalore and all had desired antibody titers above 0.5 IU/ml, without any immunosuppression. The RFFIT titers in 55% bovine in all groups were more than adequate after one year and 100% of them had anamnestic response to a single 0.2 ml booster given at one year. Few of the bovine and even one equine (Horse. Figure 4) brought for PEP at some of nearby vet hospitals were given IM rabies vaccine with local eRIG infiltration also survived. Local eRIG infiltration appeared to have covered the lacuna of longer window period required for indigenous antibodies production through IM route in bovine that are not sufficiently produced by day 14. While five times less vaccine was used in this low cost protocol and the survival was 100% compared to traditional IM protocol where survival was 66%. Pre-exposure prophylaxis was found to be effective as 0.2 ml dose of IDRV on day 0, 3, 7 and all bovine had titers higher than the desired by day seven after single 0.2 ml vaccine booster at one year. Our study points towards a possibility of having short schedules of three shots IDRV vaccination in bovine with or without local RIG (depending on presence or absence of wound/s) as PEP and single shot IDRV as PrEP, but further studies are required on a large number of animals. Our study also points out for allowing intra-dermal use in animals as well and labeling vaccines for the same as this is low cost more immunogenic and less painful compare to IM administration.

Ultrasound guided testicular fine needle aspiration in buck (Capra hircus)-An animal model

Objective:To establish ultrasound guided testicular fine needle aspiration (TFNA) as well as to assess the effectiveness of uni-directional (UD) and multi-directional (MD) TFNA in buck according to testicular cells, echotexture and gross changes of testicle, age of buck was considered.Methods:A total of 120 samples were collected with both directions (UD, n=60) and (MD,n=60) suction from testis of 10 apparently healthy bucks. All slides were stained with May-Grünwald-Giemsa and examined under light microscope with 1000× magnifications to count spermatogenic cells, spermatozoa and sertoli cells. The percentage of spermatozoa and sertoli cells were expressed as spermatic index and sertoli cell index.Results:Results revealed no difference in the presence of various spermatogenic and sertoli cells in cell cluster of slides made either unidirectional TFNA or multidirectional TFNA. Early spermatids were the most numerous, followed by late spermatids, primary spermatocytes, spermatogonia. Sertoli cell index was higher in TFNA smears of young bucks prepared from (7-13 mo) of age and spermatic index was higher in adult bucks (14-24 mo) of age. No echogenic change was observed in the echotexture of testisafter TFNA.Conclusion: It seems that TFNA has no serious ill effect on the buck testis when uni-direction aspiration is performed. Moreover, the possibility to standardize this method might provide a greater impulse to the clinical diagnostics of male animal infertility.

Customized and in situ fenestrated stent-grafts:A reinforced poly-ε-caprolactone branch cuff designed to prevent type III endoleaks and enhance hemodynamics

Superior long-term anchorage of the bridging stent-grafts from the fenestrated main body endograft could be achieved with the addition of a flared cuff,capable of preventing the previously observed fabric fraying around the fenestration as a result of the balloon angioplasty of the seal zone.This novel stent cuff design will also facilitate more complete biointegration of the devices,eliminate the hemodynamic variation as well as significantly reduce the possibility of a Type III endoleak.The feasibility of this concept is demonstrated by observations made from in-situ tests performed in a Beta endograft design.Flared cuffs made of poly(ε-caprolactone)supported with a weft-knitted polyester structure can be manufactured with various configurations to optimize the transition from the main body of the endograft,thus preventing the currently marketed designs’hemodynamic perturbation while also promoting endograft biointegration.This concept represents an evolution in branch graft design,which may enhance the long-term durability of customized fenestrations and open new applications for in-vivo graft fenestration in the near future.Further ongoing investigation to optimize its structure,X-ray opacity,fixation to the flared stent,and material biocompatibility are still required to build upon this concept’s proof.