Preparation and Behaviour of New Materials for Percutaneous Access

The reinforcing effects on hydroxyapatite （ abbreviated HA ） of phosphate glass additives were researched. The samples of reinforced HA （ abbreviated RHA ） and control material were prepared and then percutaneously implanted in the skin of experiment animal. The histomorphology of the part skin tissue were observed. By a biomimetic process, the method and conditions of forming HA coating on the surface of medical silicon rubber （ abbreviated MSR ） were stndied. The results illustrate that the phosphate glass additives have obvious reinforcing effects on HA. In the percutaueous implantation test, neither clear infiltration of inflammatory cells nor marked downgrowth of epidermis was observed for the part tissue suerounded RHA. The surface modification of MSR for percutaneous access could be attained by biomimetice synthesis of HA coating.

A comparative study on transradial vs transfemoral artery access for primary percutaneous coronary intervention in patients with acute myocardial infarction

Objective Comparative study on the feasibility,safety and outcome of transradial artery and transfemoral artery access for primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction(AMI).Methods Two hundred and eight patients with AMI episoded within 12 hours, male 159, female 49, age 58.9 ±11.9 (34～88)years, were randomly divided into transradial artery access for primary PCI (TRA pPCI) group of 106 cases and transfemoral artery access for PCI (TFA pPCI) group of 102 cases during Sept, 2000 to Aug, 2002. The protocols of the manipulation duration and the effect for TRA pPCI and TFA pPCI procedures were respectively compared, including the time of transradial artery puncture and the rate of puncture success at first time ; the time of guiding catheter engaging into target coronary ostium; the rate of patence in infarct related artery (IRA); total duration of manipulation and the successful rate.The incidence of complications such as bleeding, vessel injury,thrombi and embolism as well as the average stay of hospitalization between two groups was compared. The status and the incidance of vessel spasm were observed and the effect of medicine administration to prevent from and relieve the vascular spasm was evaluated. The time of Allen’s test before and after TRA pPCI , the inner diameter and the peak of blood velocity of the right and left radial artery were investigated with color Doppler vessel echography as well as the complications of radial artery were followed up 1 month after TRA pPCI procedure. Results Two cases in every TRA pPCI and TFA pPCI groups were crossed over each other because procedure of the transradial or transfemoral access was failure. One handred and six vessels (48 vessels in LAD,22 vessels in LCX and 36 vessels in RCA) associated with 28 vessels of total occlusion in TRA pPCI group and 102 vessels (51 vessels in LAD,18 veesles in LCX and 33 vessels in RCA) with 24 vessels in total occlusion in TFA pPCI group were angioplasticized . The successful rates of the first time puncture in access artery, the re patence IRA and pPCI were similar in TRA pPCI and TFA pPCI groups ( 93.4% vs 96.1% ;100% vs 100%; 96.2% vs 97.1% , P >0.05 ). There were no significant diffierence in the average time of puncture time of access artery ,engaging in target vessels of guiding catheters and the total procedure of PCI between the two groups ( 1.3 ±0.3s vs 1.2 ±0.3s ; 6.0 ±1.6min vs 5.8 ±0.9min ; 49.2 ±24.1min vs 46.5 ± 26.4min , P >0.05 ). The access artery complications such as bleeding ,hematoma and embolism as well the veneous thrombosis in TFA pPCI group were much more than those in TRA pPCI group(p< 0.01 ). Although slight artery spasm of 4.7% cases in TRA pPCI group was happened during the procedure of PCI , the procedure had being continued after administration of medicine to release the spasm. The time of Allen’s test ,diameter and the systolic velocity of blood in daul radial arteries were no significant change before and after pPCI.Conclusions The duration and effect by TRA pPCI for AMI with stable hemodynamics was similar to TFA pPCI. The complications such as of bleeding,vessel injury, thrombi and embolism by TRA pPCI were few, and it was unnecessary to discontinue the anticoagulation medicine. TRA pPCI might be selected as a access vessel for pPCI in AMI patients with stable hemodynamics.

Percutaneous cervical carotid artery access with stenting of the left internal carotid artery in an elderly patient

To describe the successful endovascular treatment in a nonagenarian with symptomatic internal carotid artery stenosis using direct carotid artery access. An independent 98 year-old man was admitted to our hospital for symptoms of progressive weakness with disorientation and dysphasia. Carotid Duplex ultrasonography was performed which revealed a totally occluded right internal carotid artery and high grade stenosis of the left internal carotid artery by velocities of 608/240 cm/sec. The patient refused surgical endarterectomy and thus he was referred for carotid artery stenting. Using the femoral artery approach and multiple catheter techniques, access to the common carotid artery could not be accomplished safely. The procedure was aborted and he was therefore brought back to the catheterization laboratory the following day for direct carotid access. Carotid artery stenting was accomplished by using of a 6F sheath percutaneously in the left common carotid, cerebral protection device (CPD) and a Nitinol stent. The patient was discharged the following day without complications. At 14 months follow-up the patient is functional and independent without recurrence of symptoms. Carotid artery stenting via direct access can be accomplished in patients when the femoral artery approach is anatomically prohibitive. In this case of advanced age and the patient’s refusal for surgery, direct carotid access was his only option.

Percutaneous kidney stone surgery and radiation exposure: A review

During the past 3 decades,radiation exposure(RE)has increased drastically among patients undergoing percutaneous nephrolithotomy(PCNL),thus potentially causing new cases of cancer each year.The effective dose received by patients comes from pre-and postoperative computed tomography(CT)and intraoperative fluoroscopy(FL).We reviewed literature to find novel techniques and approaches that help to decrease RE of patients and personnel.We performed PubMed search using keywords percutaneous nephrolithotomy,intraoperative fluoroscopy,radiation exposure,imaging,percutaneous access,ultrasound,computed tomography,endoscopy,reconstruction,innovations,and augmented reality.Forty-four relevant articles were included in this review.As much as 20%of patients with first diagnosed urolithiasis exceed background RE level almost 17-fold.For diagnosing purposes using low-dose and ultra-low-dose CT,as well as low-dose dual energy scan protocols can be efficient ways to decrease RE while maintaining decent accuracy.Patients with urinary stones can be effectively monitored with digital tomosynthesis,ultrasound alone or ultrasound combined with plain film of the abdomen.Percutaneous access(PCA)into the kidney can be performed with reduced or even no RE,using novel PCA methods.REs from conventional imaging techniques during diagnosis and treatment increase probability of non-stochastic radiation effects.Urologists should be aware of protocols that decrease RE from CT and FL in diagnosis and management of urinary stones.Consideration of recently developed imaging modalities and PCA techniques will also aid in adherence to the“as low as reasonably achievable”principle.

Training for percutaneous renal access on a virtual reality simulator

Background The need to develop new methods of surgical training combined with advances in computing has led to the development of virtual reality surgical simulators. The PERC MentorTM is designed to train the user in percutaneous renal collecting system access puncture. This study aimed to validate the use of this kind of simulator, in percutaneous renal access training. Methods Twenty-one urologists were enrolled as trainees to learn a fluoroscopy-guided percutaneous renal accessing technique. An assigned percutaneous renal access procedure was immediately performed on the PERC MentorTM after watching instruction video and an analog operation. Objective parameters were recorded by the simulator and subjective global rating scale （GRS） score were determined. Simulation training followed and consisted of 2 hours daily training sessions for 2 consecutive days. Twenty-four hours after the training session, trainees were evaluated performing the same procedure. The post-training evaluation was compared to the evaluation of the initial attempt. Results During the initial attempt, none of the trainees could complete the appointed procedure due to the lack of experience in fluoroscopy-guided percutaneous renal access. After the short-term training, all trainees were able to independently complete the procedure. Of the 21 trainees, 10 had primitive experience in ultrasound-guided percutaneous nephrolithotomy. Trainees were thus categorized into the group of primitive experience and inexperience. The total operating time and amount of contrast material used were significantly lower in the group of primitive experience versus the inexperience group （P=0.03 and 0.02, respectively）. Conclusions The training on the virtual reality simulator, PERC MentorTM, can help trainees with no previous experience of fluoroscopy-guided percutaneous renal access to complete the virtual manipulation of the procedure independently. This virtual reality simulator may become an important training and evaluation tool in teaching fluoroscopy-guided percutaneous renal access.