Histopathological evaluation of dog sacral nerve after chronic electrical stimulation for micturition

Histological evaluations of dog sacral nerves were carried out after stimulation for electromicturition with three types of circumneural electrodes. The use of two types of cuff arrays was associated with a marked buildup of connective tissue around the nerve and filling the lumen of the array. Nerves within the first type of cuff array (having diameters approximately that of the nerve they surrounded) were often extruded from the lumen of the cuff. In some cases, this was accompanied by moderate or marked loss of axons. It is not clear whether this phenomenon was the result of the growth of connective tissue within the cuff or tension on the electrical leads. The damage cannot be attributed to the electrical stimulation because nerves enclosed by nonpulsed electrodes showed similar damage. The second type of cuff array used in the study had an oversize lumen. There was often considerable growth of connective tissue within the cuffs, but minimal or no mechanical deformation of the included nerves and minimal loss of axons. Because of sealable lips, extrusion of the nerve from this electrode was impossible. The nerves and arrays both functioned well, and there was minimal, if any, mechanical distortion of the nerves and minimal neural damage. Nerves within a third type of array ("spinal" array) also showed no or minimal damage. The array was implanted easily, and the delicate, springlike nature of the matrix allowed close apposition to nerves of different diameters while avoiding constriction of the nerve.     

Multielectrode Nerve Cuff Stimulation of the Median Nerve Produces Selective Movements in a Raccoon Animal Model

Abstract

In this study, an electrode system consisting of twelve small platinum dot electrodes imbedded in a spiral silicone rubber insulating cuff was used to investigate the feasibility of selective (regional) stimulation of the median nerves of the raccoon. Acute experiments in four raccoons consisted of functional response observations, isometric force recordings from tendon attachments and postmortem fascicular mapping. Functional responses (elbow, wrist and/or digit flexion, pronation and/or thumb abduction) to selective stimulation were noted as dependent upon cuff electrode configuration (longitudinal tripole with and without field steering, as well as a transverse bipolar arrangement) and current level (threshold, 1/2 maximal, maximal). Muscle force recruitment curves (force as a function of stimulus amplitude) were plotted for flexor digitorum superficialis, flexor digitorum profundus, flexor carpi radialis, palmaris longus and pronator teres of three raccoons. Fascicular maps at the level of the nerve cuff were created indicating the approximate position of innervation to each of the aforementioned muscles, as well as other innervation such as paw fascicles, sensory fascicles, and elbow innervation (such as coracobrachialis). The greatest selectivity was observed at or near threshold current levels. In all tour raccoons studied, a threshold electrode choice and stimulation strategy could be identified enabling selective production of either digit flexion, wrist flexion and/or digit and wrist flexion. It was possible to elicit a selective pronation response at threshold in three of the four animals. Selective elbow flexion at threshold could be produced in all four experiments. With stronger currents, additional movements were usually induced. The raccoon therefore appears to be a suitable, if challenging, animal model for further development of not only nerve cuff electrode approaches but perhaps other stimulation electrode technologies prior to human neuroprosthetic studies. (J Spinal Cord Med 1997; 20:233-243)     

New Easy to Install Nerve Cuff Electrode Using Shape Memory Alloy Armature

This paper presents an easy to install nerve cuff electrode dedicated to functional electrical stimulation (FES). In this new device, a shape memory alloy (SMA) armature is used to perform the closing of the electrode. This technique makes the electrode installation around the nerve much easier, quicker, and safer. Both remarkable mechanical properties of SMA materials, namely, shape memory effect and superelasticity, can be used to obtain the desired mode of electrode closing. The fabrication procedure of the new electrode is described. It does not require any expensive or complex techniques. Bipolar and tripolar electrodes have been manufactured with an inner diameter of 1.6 mm and a cuff wall thickness of 0.8 mm. These electrodes are to be used for FES of the bladder in spinal cord injured patients. Acute studies in dogs are being carried out to validate the device and the implantation procedure.     

Minimally invasive trans-mediastinal endoscopic approach to insert phrenic stimulation electrodes in the human diaphragm: a preliminary description in cadavers

Objective: Diaphragm pacing by phrenic nerve (PN) stimulation is currently used for patients with central respiratory paralysis to be weaned from mechanical ventilation. Electrodes are inserted either through bilateral thoracotomy or through four ports laparoscopy. The aim of this experimental work is to demonstrate the feasibility of trans-mediastinal bilateral implantation of PN electrodes using a flexible gastroscope introduced through a cervical incision in human cadavers. Methods: Ten refrigerated and non-embalmed cadavers were used. The gastroscope was introduced through a cervical incision into the latero-tracheal space and then subsequently into both pleura by opening the mediastinal pleura. After identification of the PN, electrodes were introduced through an intercostal space to the desired diaphragmatic location using a long, pliable needle with the electrode loaded in its lumen. Results: Results are described for each hemi-diaphragm not for an anatomic subject. Mediastinal exploration and introduction of the video gastroscope into the pleural cavities proved easy in all subjects. Pleural adherences were present in five hemi-diaphragms. The central tendon of both hemi-diaphragms could be identified unambiguously in all the subjects. Identification of the entry point of the phrenic nerve into the diaphragm was straightforward in 10 hemi-diaphragms. In the remaining 10, this proved more difficult because of mediastinal fat or lung parenchyma. Introduction of the electrode-holding needles through the intercostal space and their insertion close to the phrenic nerve entry point was also easy. Withdrawal of the needle from the diaphragm and ‘capture’ of the hook were successful on the first attempt in 14 hemi-diaphragms, but failed in six others in whom a second attempt was necessary. Conclusion: Trans-mediastinal implantation of PN stimulation electrodes is possible using a flexible endoscope. This application of endoscopic surgery could allow a minimally invasive placement of PN electrodes in patients with central respiratory paralysis, for example, at the time of tracheostomy.     

The Effect of Local Use of Nandrolone Decanoate on Rotator Cuff Repair in Rabbits

ABSTRACT

Objective: There is still controversy about the effect of anabolic steroid on connective tissue. This study examines the hypothesis that the local use of nandrolone decanoate, an anabolic steroid on rotator cuff, facilitates the healing process when used in combination with surgical repair. Methods: Forty-eight male rabbits were divided in four groups with anabolic steroids (Nandrolone Decanoate 10 mg/kg) and immobilization as variables. The groups were the following: first group, nonsteroid use-immobilization (NSI); second group, nonsteroid use-nonimmobilization (NSNI); third group, steroid use-immobilization (SI); fourth group steroid use-nonimmobilization (SNI). Every rabbit underwent a rotator cuff incision and reconstruction. Fifteen days later the tendons were sent for biomechanical and histological evaluation. Results: Groups that did not receive anabolic steroids showed better healing and more tendon strength in comparison to groups that received anabolic steroids. Microscopic examination of specimens from the groups without the use of anabolic steroid showed extensive fibroblastic activity whereas the specimens from those groups with anabolic steroid use showed focal fibroblastic reaction and inflammation. Immobilization provided better results in the groups with anabolic steroid use but it did not influence healing in groups without steroids. Conclusions: The effect of local nandrolone decanoate use on a rotator cuff tear is detrimental, acting as a healing inhibitor.     

Suprascapular nerve neuropathy leads to supraspinatus tendon degeneration

BackgroundNowadays most of attention regarding rotator cuff is payed to how to reduce the failure after rotator cuff surgical repair rather than how to prevent the rotator cuff tear before surgery. The etiologies of rotator cuff tear are still unclear. As we all know, the nerve system include brain, spinal cord, sensory organs and all the neurons allover our body coordinates the homoeostasis of our body. We hypothesis that the nerve injury proximal to suprascapular nerve can leads to rotator cuff degeneration even tear.MethodsThirty-six SD rats were used. A defect on the suprascapular nerve was made on the right side and a sham surgery on the nerve (expose nerve only) at the left side. The insertion of supraspinatus tendon and supraspinatus muscle were harvested for testing. Twelve rats were sacrificed for biomechanical (six rats) and histological (six rats) properties were evaluated at 3, 6, and 9 weeks after surgery, respectively.ResultsSignificant inferior biomechanical properties of rotator cuff were found in nerve injured side compared to the nerve intact side at 6–9 weeks. Significant muscle atrophy was found at nerve injured side from 3 to 9 weeks. The enthesis of nerve injured side showed significant excessive cell maturity, reduced cellularity, smaller metachromasia area and more type-III collagen especially at 9 weeks after surgery.ConclusionsThe neuropathy proximal to suprascapular nerve can leads to rotator cuff degeneration even tear. The nerve dysfunction maybe an important etiology for rotator cuff tear.     

Chronic instrumentation with model microstimulators in an animal model of the lower urinary tract

BACKGROUND: Microstimulators are a new type of neuroprosthetic device that should be considered for applications such as micturition control after spinal cord injury (SCI). These devices are small (less than 25 mm by 5 mm) and the electrodes are located on the ends of the stimulator. The aim of the current study was to develop methods for chronic implantation of model microstimulators (M-Micro) on the bladder wall and pelvic plexus of female cats. A postmortem evaluation of the effects of 3 months of implantation is reported. METHODS: Techniques to produce the M-Micro are described. Four of these devices were implanted in 4 female cats and maintained after the initial instrumentation surgery and a second survival surgery for SCI (at T10). Using a single suture tied around the M-Micro, these devices were secured to the bladder wall or the fat pads adjacent to the pelvic plexus. Additional instrumentation was implanted, including 2 catheters in the bladder, 1 abdominal balloon, and electromyography electrodes in the urethral and anal sphincters. Postmortem observations of the location of the M-Micro on the bladder wall were conducted after fixation. RESULTS: The animals' conditions were good. One animal was sacrificed early because of a skin infection. A single suture was sufficient to anchor the M-Micro. However, during the surgical implantation the pelvic plexus M-Micro ended up close to the bladder neck. Extensive fibrous connective tissue formed around the M-Micro and implanted catheters on the bladder wall. This appeared to result, in part, from multiple devices implanted on or near the bladder wall. CONCLUSIONS: These pilot studies showed that the M-Micro could be easily constructed and secured to the bladder wall or fat pads close to the pelvic plexus. There was a concern that the pelvic plexus location for the M-Micro ended near the bladder neck during the surgical implantation; however, these devices did not appear to migrate over this short, 3-month implantation period. The extensive connective tissue responses of the bladder wall to the tubes, wires, and M-Micro was a major concern. The M-Micro appears to be a good device to assess the potential of commercial microstimulators for use in micturition control.     

Animal study of pudendal nerve cuff electrode implants for collision block of motor activity

Through previous acute animal studies we have developed an asymmetric two electrode cuff (ATEC) implant for collision block of orthodromic pudendal nerve motor activity. In this paper we describe preliminary results concerning the effectiveness and safety of unilateral pudendal nerve ATECs implanted for 1 month in three adult male dogs. An apparent temporary pressure block of large fiber conduction in the implanted nerve trunks produced distinctive differences between the 2-week and 4-week tests in all three animals. In the first two implants significant nerve trunk tissue damage due presumably to surgical trauma and/or cuff encapsulation decreased the effectiveness of ATEC function; however, with the third implant virtually no damage was detected and ATEC effectiveness was high.     

Influence of a nerve injury proximal to the suprascapular nerve on healing of repaired rotator cuff tear

BackgroundMassive rotator cuff tears have a high rate of re-injury because of severe fatty infiltration. Our data showed that injuries proximal to the suprascapular nerve may be one cause of massive rotator cuff tears. The purpose of this study was to evaluate, using a rat model, how brachial plexus injury associated with a massive rotator cuff tear influences healing of the rotator cuff repair.MethodsSeventy Sprague–Dawley rats were divided into three groups: rotator cuff tear with BP injury (DT group) (n = 28), rotator cuff tear without brachial plexus injury (T group) (n = 28), and a sham-operated group (n = 14). In the DT group, the rotator cuff tear was made and repaired 4 weeks after brachial plexus ligation. The gross assessment (evaluated the wet weight), biomechanical testing (evaluated the yield stress and the Young's modulus) and histological analyses (using the Bonar scale) were performed at baseline in the sham group, and at 4 and 12 weeks postoperatively in the DT and T groups (n = 7/group/time).ResultsMean wet weight and yield stress were significantly lower in the DT group than in the T group. Additionally, the mean Young's modulus was significantly higher in the DT group than in the T group. Histologically, greater tendon degeneration was observed around the musculotendinous junction in the DT group than in the T group.ConclusionThe gross, biomechanical and histological data show that the repaired rotator cuff tendon with brachial plexus injury in rats does not heal as well as a repaired tendon without an accompanying brachial plexus injury. This suggests that more proximal neuropathy is one risk factor for re-tear of a repaired rotator cuff tendon.     

Revision and removal of stimulating electrodes following long-term therapy with the vagus nerve stimulator

BACKGROUND

A significant concern about vagus nerve stimulation therapy has been the disposition of the spiral stimulating electrodes once treatment is considered ineffective or is no longer desired. Because the electrodes are wrapped around the vagus nerve, there is the potential for nerve injury during their removal.

METHODS

We attempted removal of the spiral stimulating electrodes from 10 patients who received long-term vagus nerve stimulation therapy for drug-resistant epilepsy. In some patients, replacement with electrodes was also performed for poorly functioning leads.

RESULTS

The mean duration of electrode implantation was 3.7 ± 2.2 years (range 1.1–7.3 years). In seven patients, the old electrodes were removed completely from the nerve. No adverse events occurred intraoperatively or postoperatively.

CONCLUSIONS

Our results indicate that the spiral electrodes may be safely removed from the vagus nerve, even after the electrodes have been implanted for several years. The reversibility of lead implantation may enhance the attractiveness of vagus nerve stimulation therapy for patients with medically-intractable epilepsy.     

Do Direct Current Electric Fields Enhance Micturition in the Spinal Cat?

ABSTRACT

Changes in micturition behavior and motoneuron ultrastructure were studied in spinal cats to determine the effects of direct current (DC) electric field treatment. Adult cats received a complete injury at T8. A treatment group with an implanted 15 pA DC source and electrodes positioned near the lesion site was compared with non-treatment groups that were either operated or unoperated. Both bladder emptying with Crede and the withdrawal reflex were improved in the treatment group compared with the non-treatment group. Urodynamic procedures showed that high urethral resistance and pelvic floor activity following spinal injury was partially reduced in the stimulated cat, indicating inhibition of the urethral sphincter. The ultrastructural analysis of Onuf’s nucleus suggested a similar synaptic input in all three groups. In conclusion, possible activation of inhibitory processes and/or neural plasticity best explain the early improvement of bladder function seen following electrical stimulation. (J Spinal Cord Med 19:225–233)     

肩袖撕裂合并冻结肩行手法松解后的关节镜下表现及影响因素分析

目的 观察肩袖撕裂合并冻结肩行手法松解后的关节镜下表现,并分析其影响因素。方法 回顾性分析2017年9月至2019年9月收治的68例肩袖撕裂合并冻结肩病人的病例资料,其中,男35例,女33例,年龄为（52.68±6.54）岁,均行一期麻醉后手法松解联合关节镜检查并肩袖修复术,观察手法松解后的关节镜下表现,比较松解损伤病人和未损伤病人之间的性别、患侧、肩袖撕裂程度差异,分析患肩关节疼痛时间、肩关节活动受限病程和实施手法松解时间与手法松解损伤的相关性。收集病人的数字分级法（numerical rating scale, NRS）疼痛评分、美国肩肘外科医师学会（American Shoulder and Elbow Surgeons, ASES）评分、Constant-Murley评分及丹麦健康与医疗管理局（Danish Health and Medicine Authority）满意度评分。结果 共16例（23.53%）发生手法松解损伤,其中单一损伤者12例,两种及以上损伤者4例,损伤类型为前关节囊撕裂（3例,18.75%）、下关节囊撕裂（6例,37.50%）、盂肱中韧带撕裂（7例,43.75%）、盂肱下韧带肱骨端撕裂（humeral avulsion of the glenohumeral ligament, HAGL）（3例,18.75%）、前盂唇撕裂（2例,12.50%）。松解损伤病人和未损伤病人之间的年龄（P=0.431）、性别（P=0.893）、患侧（P=0.673）、肩袖撕裂程度（P=0.723）、患肩关节疼痛时间（P=0.813）、肩关节活动受限病程（P=0.250）、实施手法松解时间（P=0.125）均未见显著差异。松解损伤组和松解无损伤组术后NRS评分均较术前明显降低,肩关节功能评分较术前明显改善（P均＜0.05）;手术前后的NRS评分、肩关节功能ASES评分、Constant-Murley评分、病人满意度评分比较,差异均无统计学意义（P均＞0.05）。结论 肩袖撕裂合并冻结肩行麻醉后肩关节手法松解联合关节镜下肩袖修复术可能导致单一或合并的镜下损伤表现,年龄、性别、患侧、肩袖撕裂程度、患肩关节疼痛时间、肩关节活动受限病程、实施手法松解时间等因素与发生手法松解损伤无明确相关性。     

Single minimum incision endoscopic radical nephrectomy for renal tumors with preoperative virtual navigation using 3D-CT volume-rendering

Background

Intraurethral electrical stimulation (IES) of pudendal afferent nerve fibers can evoke both excitatory and inhibitory bladder reflexes in cats. These pudendovesical reflexes are a potential substrate for restoring bladder function in persons with spinal cord injury or other neurological disorders. However, the complex distribution of pudendal afferent fibers along the lower urinary tract presents a challenge when trying to determine the optimal geometry and position of IES electrodes for evoking these reflexes. This study aimed to determine the optimal intraurethral electrode configuration(s) and locations for selectively activating targeted pudendal afferents to aid future preclinical and clinical investigations.

Methods

A finite element model (FEM) of the male cat urethra and surrounding structures was generated to simulate IES with a variety of electrode configurations and locations. The activating functions (AFs) along pudendal afferent branches innervating the cat urethra were determined. Additionally, the thresholds for activation of pudendal afferent branches were measured in α-chloralose anesthetized cats.

Results

Maximum AFs evoked by intraurethral stimulation in the FEM and in vivo threshold intensities were dependent on stimulation location and electrode configuration.

Conclusions

A ring electrode configuration is ideal for IES. Stimulation near the urethral meatus or prostate can activate the pudendal afferent fibers at the lowest intensities, and allowed selective activation of the dorsal penile nerve or cranial sensory nerve, respectively. Electrode location was a more important factor than electrode configuration for determining stimulation threshold intensity and nerve selectivity.     

Electrochemical and Electrophysiological Performance of Platinum Electrodes Within the Ninety‐Nine‐Electrode Stimulating Nerve Cuff

The trend in neural prostheses using selective nerve stimulation for electrical stimulation therapies is headed toward single‐part systems having a large number of working electrodes (WEs), each of which selectively stimulate neural tissue or record neural response (NR). The present article reviews the electrochemical and electrophysiological performance of platinum WE within a ninety‐nine‐electrode spiral cuff for selective nerve stimulation and recording of peripheral nerves, with a focus on the vagus nerve (VN). The electrochemical properties of the WE were studied in vitro using the electrochemical impedance spectroscopy (EIS) technique. The equivalent circuit model (ECM) of the interface between the WE and neural tissue was extracted from the EIS data and simulated in the time domain using a preset current stimulus. Electrophysiological performance of in‐space and fiber‐type highly selective vagus nerve stimulation (VNS) was tested using an isolated segment of a porcine VN and carotid artery as a reference. A quasitrapezoidal current‐controlled pulse (stimulus) was applied to the VN or arterial segment using an appointed group of three electrodes (triplet). The triplet and stimulus were configured to predominantly stimulate B‐fibers and minimize the stimulation of A‐fibers. The EIS results revealed capacitive charge transfer predominance, which is a highly desirable property. Electrophysiological performance testing indicated the potential existence of certain parameters and waveforms of the stimulus for which the contribution of the A‐fibers to the NR decreased slightly and that of the B‐fibers increased slightly. Findings show that the design of the stimulating electrodes, based on the EIS and ECM results, could act as a useful tool for nerve cuff development.     

The effect of in vivo created vascularized neurotube on peripheric nerve regeneration

IntroductionCreating vascularized nerve conduits for treatment of nerve gaps have been researched, however, these methods need microsurgical anastomosis thereby complicating the nerve repair process. Thus, the concept of vascularized nerve conduits has not popularized up till now. The aim of this study is to evaluate the effects of vascularized and non-vascularized biological conduits on peripheral nerve regeneration.Material and methodsFollowing ethical board approval, 15 Sprague-Dawley rats were used in the study. The rats were equally divided into three groups. In group I, a silicon rod was inserted next to the sciatic nerve of the rat and connective tissue generated around this rod was used as a vascularized biological conduit. In group II, a silicon rod was inserted into the dorsum of the rat and connective tissue generated around this rod was used as a non-vascularized biological conduit. In group III, autogenic nerve graft was used to repair the nerve gap. The contralateral sciatic nerve is used as a control in all rats. Macroscopic, electrophysiological and histomorphometric evaluations were performed to determine the nerve regeneration.ResultsThere was no statistically significant difference between groups, in terms of latency. However, the mean amplitude of group I was found to be higher than other groups. The difference between group I and II was statistically significant. Myelinated axonal counts in group I was significantly higher than groups II and III.ConclusionOur results showed that vascularized biological conduits provided better nerve regeneration when compared to autografts and non-vascularized biological conduits. Creation and application of vascularized conduits by using the technique described here is easy. Although this method is not an alternative to autogenic nerve grafts, our results are promising and encouraging for further studies.     

Evaluation of a silicon-substrate modiolar eighth nerve implant in a guinea pig

The availability of thin-film multichannel electrodes provides new possibilities for implantation and direct stimulation of the modiolar portion of the auditory nerve. Electrodes in direct contact with the auditory nerve should be functional at lower thresholds and might require fewer remaining neurons for stimulation compared to electrodes in the scala tympani. This strategy would also provide close contact with neural elements subserving a greater frequency range. Implantation of the eighth nerve may also be advantageous in profoundly deaf subjects who lack an implantable scala tympani. In this study we evaluated the effect of surgical implantation and chronic placement of a silicon substrate implant in the modiolar portion of the auditory nerve of the guinea pig. Of six chronically implanted ears, five showed changes limited to the loss of spiral ganglion cells in the canal of Rosenthal, immediately adjacent to the implant. The sixth ear showed more extensive cochlear alteration in a pattern suggestive of vascular injury. In separate acute experiments, implants were placed in the modiolar portion of the auditory nerve and electrophysiologic analysis was performed. Middle latency responses with good morphology were obtained at thresholds below those found with scala tympani implants. Input-output functions exhibited a plateau in response amplitude at stimulus levels below thresholds for seventh or vestibular portion of the eighth nerve. Further modifications of the modiolar portion of the auditory nerve electrode design will include development of an electrode interconnect that will allow chronic implantation with stimulation.     

The role of materials biocompatibility for functional electrical stimulation applications

The biocompatibility of all metallic, polymeric, or ceramic materials used for functional electrical stimulation is governed by the inevitable inflammatory tissue response, but possibly also by immunological reactions to the bulk material or released constituents. Besides chemical, physical, and corrosion properties of the conductive electrode materials, increased surface area and roughness of the electrode can influence tissue contact and signal delivery, and can also affect electrode-tissue impedance due to increased connective tissue encapsulation. The polymeric materials used for electrode insulation and those for leads and stimulator packaging seem more or less compatible in an aggressive biological environment. For the long-term performance of electrodes and leads, the relative motion in the various implant bed situations also has to be considered.     

全关节镜下肩袖修补术对老年肩袖损伤患者术后72 h内疼痛程度和并发症的影响

目的:分析全关节镜下肩袖修补术与小切口肩袖修补术对老年肩袖损伤患者的临床效果。方法:选取2017年1月至2018年11月收治的60例老年肩袖损伤患者作为研究对象,男37例,女23例;年龄61~77(63.45±12.34)岁;病程6~12(5.32±1.02)个月;左侧29例,右侧31例。其中,行全关节镜下肩袖修补术者30例,为观察组;行小切口肩袖修补术者30例,为对照组。观察并记录两组患者术前术后美国加州大学肩关节评分系统(University of California,Los Angeles,UCLA)评分,美国肩肘外科协会(American Shoulder and Elbow Surgeons,ASES)评分,Constant-Murley评分,肩关节前屈活动度、外旋活动度、外展活动度,术后72 h内视觉模拟疼痛评分(visual analogue scale,VAS)及并发症发生情况,然后进行对比分析。结果:两组患者术后UCLA评分、ASES评分、Constant-Murley评分较术前均显著提高(P<0.05),两组术后UCLA、ASES、Constant-Murley评分相比差异无统计学意义(P>0.05)。两组患者术后肩关节前屈活动度、外旋活动度、外展活动度较术前均显著增加(P<0.05),术后两组间比较差异无统计学意义(P>0.05);观察组术后24、48、72 h VAS低于对照组(P<0.05);观察组并发症总发生率13.33%(4/30)低于对照组33.33%(10/30)(P<0.05)。结论:全关节镜下肩袖修补术和小切口肩袖修补术均可以改善老年肩袖损伤后的肩部功能,但全关节镜下肩袖修补术后72 h内疼痛程度和并发症均明显优于小切口肩袖修补术,可根据患者临床实际情况与需求进行选择。     

Subchronic Stimulation Performance of Transverse Intrafascicular Multichannel Electrodes in the Median Nerve of the Göttingen Minipig

This work evaluated the subchronic stimulation performance of an intraneural multichannel electrode (transverse intrafascicular multichannel electrode, TIME) in a large human‐sized nerve. One or two TIMEs were implanted in the right median nerve above the elbow joint in four pigs for a period of 32 to 37 days (six TIMEs in total). The ability of the contact sites to recruit five muscles in the forelimb was assessed via their evoked electromyographic responses. Based on these responses, a selectivity index was defined. Four TIMEs were able to selectively recruit a subset of muscles throughout the implantation period. The required recruitment current significantly increased, while there was a tendency for the recruitment selectivity to decrease over time. Histological assessment showed that all TIMEs remained inside the nerve and that they were located between fascicles. The average thickness of the encapsulation of the electrode was estimated to be 115.4 ± 51.5 μm (mean ± SD). This study demonstrates the feasibility of keeping the TIME electrodes fixed and functional inside a large polyfascicular human‐sized nerve in a subchronic setting.     

CT引导下经肺或肋膈角射频消融治疗肝顶部肿瘤

目的探讨CT引导下、经肋膈角或肺组织对肝顶部肿瘤进行射频消融治疗的安全性及可行性。方法对45例肝顶部肿瘤患者采用CT引导下经肋膈角或肺组织入路行射频消融治疗。记录过肺组织或肋膈角电极针数目及肺组织内电极针长度。分析围手术期并发症及临床疗效。结果 45例肝顶部肿瘤患者,原发性肝癌34例,转移癌11例。全身麻醉34例,局部麻醉11例。病变最大径0.91~6.67cm,中位数1.83cm。肺组织内电极长度0~59.42mm,中位数9.90mm。单针过肺13例,2针同时过肺13例,3针同时过肺3例,单独1支过肋膈角8例,1支过肋膈角同时1支过肺组织7例,1支过肋膈角同时2支过肺组织1例。无症状少量气胸11例(11/45,24.44%)。肺组织穿刺针道少量出血6例,右肩部疼痛9例,1周左右症状消失。随访3~14个月,局部复发7例(7/45,15.56%)。结论经肋膈角或肺穿刺射频消融治疗肝脏恶性肿瘤安全可行,尤其对于射频消融治疗时常规路径无法到位的肝顶部肿瘤,可采用此方法。