Proximal Direction Research Articles

Abstract TMP5: Vessel Status Findings in Patient Candidates Transferred for Endovascular Treatment. Data From Catalonia’s Code Stroke Registry

The aim of this study was to determine changes in vessel status between PSC and CSC according to site and occlusion level, rtPA-treatment, and pre-specified time intervals. Methods: Observational, multicenter study, from a prospective, government-mandated, population-based registry. We selected data from candidates to EVT with documented LVO at PSC who were transferred to CSC from January 2017 to June 2019. We used clinical variables and time intervals as the Symptom-Onset to Vascular-Imaging at CSC (SOTVI2). The primary endpoint was defined as no-occlusion/distal occlusion ineligible for EVT at CSC arrival (NOEVTatCSC) as was utilized. Results: From 589 patients, 37% received rtPA. Rate of NOEVTatCSC was 10.5% (n: 62) and 87% were treated with rtPA, being 35.8% of causes to exclude EVT at CSC arrival. In univariate analysis, lower baseline-NIHSS (median 12 vs. 16 p<0.01), RACE-scale (median 5 vs. 6; p=0.04) and SOTVI2-time (mean-minutes 268.7 vs. 317.2; p=0.04), rtPA treatment (13.7% Vs. 5.0%; p<0.01), and M2 occlusion (16.8% Vs. 9%; p= 0.02) were associated with NOEVTatCSC. In multivariate analysis, only rtPA-treatment was associated with NOEVTatCSC (OR: 4.65, 95%CI: 1.73-12.4, p= 0.003). In the rtPA subgroup, Basilar occlusion (28% Vs. 12%; p=0.04), lower baseline-NIHSS (13 Vs. 16; p<0.01) and SOTVI2 times ≤240 minutes (28.9% Vs. 15.4%; p=0.02) were associated with NOEVTatCSC. In Multivariate analysis SOVI2 ≤240 minutes (OR: 2.109 95%CI: 1.008-4.401, p=0.04) emerged as the only predictor of NOEVTatCSC. Changes in the vessel status according to initial occlusion at PSC in anterior circulation were observed, and occurred in both; proximal and distal direction. In 11.2% of cases, occlusion site at CSC was more proximal than at PSC. Conclusion: In patient candidates for EVT transferred from PSC to CSC, NOEVTatCSC is infrequent making the need of a second vascular study before the angiogram at CSC arguable. Despite of its modest effect, tPA-treatment at PSC is the only factor associated with NOEVTatCSC. This could be most relevant in basilar occlusions and in the first 4-hours. Changes in the vessel status according to initial occlusion in PSC occur in anterior circulation. Future studies addressed to determine factors related to these changes are warranted.

Transport and fate of inhaled particles after deposition onto the airway surface liquid: A 3D numerical study

In this paper, a numerical investigation is carried out to provide insights into the fate of inhaled aerosols after their deposition on the lung lining fluid in both healthy and diseased states. Pulmonary drug delivery is a well-known non-invasive route of administration compared to intravenous delivery. Aerosol particles are formulated and used as drug carriers, which are then sent to the airways using aerosol drug delivery devices. This approach is useful for site-specific treatment of lung diseases, treatment of central nervous system (CNS) disorders and a variety of other diseases. Bioavailability of the inhaled therapeutic particles after landing on the airway lining fluid can be significantly altered by the lung muco-ciliary clearance, a process through which hairlike structures known as cilia beat in a harmonised manner and induce the mucus in the proximal direction, leading to an effective clearance of the foreign inhaled particles entrapped by this sticky layer from the airways. Here, we set up a 3D computational model of ciliary arrays interacting with periciliary liquid film (i.e. confined between the epithelium and mucus layer) and a detailed analysis is conducted to better understand the fate of drug nanoparticles that are able to penetrate the mucus. Consistent with clinical findings, we find that the actions of cilia result in a low rate of drug retention and absorption by the pulmonary tissues in healthy lungs. However, under conditions associated with abnormal ciliary beats, the retention time of particles is notably increased at the site of release. Nonetheless, the results associated with some of the ciliary impairments reveal that deposition of drug aerosols on the ciliated cells may still be a significant challenge. These findings have potentially important implications on the modification of therapeutic drug particles to achieve a higher absorption rate.

Anatomy and venous hemodynamics of gait phases

The Valve-Muscular Pump (MVP) of the lower limb, a kind of peripheral heart, is principally activated during walking, by the succession of gait phases. The pump has three parts, which work in a coordinated way. The foot pump, due to the compression of the predominating lateral plantar vein during the contact on the ground (40% of gait event), “eject” 20-30 cm3 of blood into the posterior tibial vein and, in alternative, in the anterior tibial, peroneal and saphenous veins connected by perforators. The distal calf pump, activated during dorsiflexion of the ankle (passive 20% and active 40% of gait event), when the calf muscles are stretched and their distal part descends within the fascial sheath. This movement acts like a piston which expels venous blood in proximal direction. The proximal calf muscle pump due to sural and gastrocnemius muscles rich in venous sinuses that are strongly squeezed during the impulse phase of the step. During dorsiflexion of the ankle (passive or active) space is given to the blood coming from the foot pump (due to weight bearing), that will feed in prevalence the posterior tibial veins. These two systems are “in series”: the foot pump cannot expel the blood into the deep veins if these are not regularly emptied. The proximal pump, at the opposite, is very strong and can void a high volume of blood in the popliteal vein, even in the absence of a favourable gradient as it works “in parallel”.

АМБИВАЛЕНТНОСТЬ ХРОНИЧЕСКОГО ВОСПАЛЕНИЯ В СЛИЗИСТОЙ ОБОЛОЧКЕ ЖЕЛУДКА

For peptic ulcer disease, the etiological role of H. pylori infection has been proven, 60-90% of gastric cancer cases are associated with H. pylori. The bacterium is recognized as a first-order carcinogen. An association has been established between the successful elimination of H. pylori and a reduced risk of gastric cancer and relapse of peptic ulcer. In the pathogenesis of chronic inflammation in the gastric mucosa associated with H. pylori, there are reference points that determine the further path of development of the pathology. If peptic ulcer is not a consequence of the direct damaging effect of NSAIDs, it is associated with the development of gastritis. In gastric ulcer, gastritis is found in both the antrum and the fundus of the stomach Atrophy of the glands begins in the antrum, then its foci are found in the fundus on the front and back walls. Gradu- ally they increase in size, merge with each other, the acid secreting zone decreases, and the border between the fundus and pyloric glands shifts in the proximal direction. With atrophic fundus gastritis, the likelihood of developing high ulcers and stomach cancer increases. Significant increase in apoptosis processes with relative rigidity of proliferation leads to the formation of ulcer, and carcinogenesis is due to excessive proliferation and accumulation of cell mutations. One of the subjects of damage is Cag A H. pylori protein, which implements remodeling of the gastric epithelial barrier. Among its effects are modulation and impaired proliferation of gastric epithelium, leading to morphological changes. The aggressive action of Cag A protein enhances toxic doses of alcohol and smoking, supporting inflammation and causing damage to the gastric mucosa. Despite the common etiology and pathogenesis of gastric ulcer and gastric cancer, the relationship with the de- velopment of atrophic pangastritis and the similarity of convention risk factors determines that the key point in the manifestation of gastric cancer is a genetic predisposition in the form of gene polymorphism causing severe atrophy as a result of chronic inflammation.

Migrating biliary stent in an older woman with choledocholithiasis

Endoscopy-guided plastic biliary stent insertion is successfully used to treat many biliary and pancreatic disorders. However, stent migration may occur in patients who undergo endoscopic stenting. Migration of the biliary stent generally occurs in the proximal direction, and displaced stents are usually removed by endoscopy. Distal stent migration occurs in 5–10% of biliary stent migration cases. Spontaneous and asymptomatic distal migration of the stent is rare. We report the case of a 76-year-old woman who had undergone biliary stenting with endoscopic retrograde cholangiopancreatography (ERCP) 1 month prior due to choledocholithiasis and was admitted to the emergency department (ED) with asymptomatic, spontaneous distal migration of her stent via normal passage to the anus. To our knowledge, no uncomplicated and asymptomatic distal biliary stent migration case has been previously reported in the literature.

Identification of cutaneous arteries of the perineal and caudal thigh region: A cadaveric study in 12 cats.

To describe the location of the dorsal perineal artery in cats and identify landmarks for axial pattern flaps based on this vessel. Anatomic study. Twelve feline cadavers. Nonselective barium sulfate angiography was performed via injection of the descending aorta. Skin excised from the perineum and thighs was evaluated via gross inspection and radiography to identify angiosomes. The dorsal perineal artery had a robust angiosome on the caudal thigh in 10 of 12 cadavers. The artery exited the ischiorectal fossa along the muscular furrow between the biceps femoris and semitendinosus muscles and passed sagittally toward the popliteal fossa in those 10 specimens. All cadavers had a consistent angiosome based on the ventral perineal artery, which was located on the caudomedial thigh. All cadavers also had a consistent angiosome from a cutaneous branch of the popliteal artery, which traveled in a distal to proximal direction starting at the popliteal fossa. The dorsal perineal artery had a large cutaneous angiosome on the caudal thigh, which was consistent in most cats. The ventral perineal artery and cutaneous branch of the popliteal artery had consistent but smaller cutaneous angiosomes. The axial pattern flaps of the cutaneous branches of the dorsal and ventral perineal arteries and the popliteal artery provide a robust arterial blood supply to the skin of the perineum and the caudal thigh. These three flaps may therefore have adequate vascular supply to consistently survive in most cats.

Biomechanical signaling and collagen fiber reorientation during distraction enterogenesis

Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common subset of intestinal failure. Spring distraction uses an intraluminal axial mechanical force to stimulate the growth and elongation of the small intestine. The tissue close to the distracted intestinal segment may also experience signaling to grow. In this study we examined the effects of distraction enterogenesis at different post-operative days on the thickness of small intestinal layers in the intestine proximal and distal to the distracted segment, as well as how the submucosal collagen fibers were reoriented. It was observed that not only different layers of intestine wall in distracted segment showed thickening due to the applied mechanical force but also adjacent tissues in both distal and proximal directions were impacted significantly where they showed thickening as well. The orientation of collagen fibers in submucosa layer was also significantly impacted due to the mechanical force in both distracted and adjacent tissue. The effect of the applied mechanical force on the main distracted tissue and the radial growth of the adjacent tissue strongly suggest actions of paracrine signaling.

Impact of intrafraction prostate motion on clinical target coverage in proton therapy: A simulation study of dosimetric differences in two delivery techniques.

PurposeTo investigate the dosimetric impact of prostate intrafraction motion on proton double‐scattering (DS) and uniform scanning (US) treatments using electromagnetic transponder‐based prostate tracking data in simulated treatment deliveries.MethodsIn proton DS delivery, the spread‐out Bragg peak (SOBP) is created almost instantaneously by the constant rotation of the range modulator. US, however, delivers each entire energy layer of the SOBP sequentially from distal to proximal direction in time, which can interplay with prostate intrafraction motion. This spatiotemporal interplay during proton treatment was simulated to evaluate its dosimetric impact. Prostate clinical target volume (CTV) dose was obtained by moving CTV through dose matrices of the energy layers according to prostate‐motion traces. Fourteen prostate intrafraction motion traces of each of 17 prostate patients were used in the simulated treatment deliveries. Both single fraction dose‐volume histograms (DVHs) and fraction‐cumulative DVHs were obtained for both 2 Gy per fraction and 7.25 Gy per fraction stereotactic body radiotherapy (SBRT).ResultsThe simulation results indicated that CTV dose degradation depends on the magnitude and direction of prostate intrafraction motion and is patient specific. For some individual fractions, prescription dose coverage decreased in both US and DS treatments, and hot and cold spots inside the CTV were observed in the US results. However, fraction‐cumulative CTV dose coverage showed much reduced dose degradation for both DS and US treatments for both 2 Gy per fraction and SBRT simulations.ConclusionsThis study indicated that CTV dose inhomogeneity may exist for some patients with severe prostate intrafraction motion during US treatments. However, there are no statistically significant dose differences between DS and US treatment simulations. Cumulative dose of multiple‐fractions significantly reduced dose uncertainties.

Minimally invasive intramedullary fixation with flexible nails in the treatment of metatarsal neck fractures

Objective: This study was designed to retrospectively assess patients with deviated central metatarsal neck fractures subjected to reduction and fixation with flexible intramedullary nails. Methods: Thirty-six patients (36 feet) diagnosed with acute fractures of one or more metatarsals and whose therapeutic indication was exclusively surgical were evaluated between June 2010 and August 2011. Considering the metatarsophalangeal joint, such injuries should be located up to two centimeters in the proximal direction of this segment, with plantar deviation greater than 10 degrees and translation greater than three millimeters in any plane. Minimally invasive intramedullary fixation with two flexible titanium nails was used when adequate stability was not obtained with the use of one nail. The visual analog scale (VAS), American Orthopedic Foot & Ankle Society (AOFAS) forefoot score and specific statistical tests were used. Results: There was a significant (p<0.001) improvement in the results until 6 months of follow-up. There was no significant difference (p>0.05) in the results between 6 and 12 months of follow-up. The average time of consolidation was 8 weeks, and there were no complications during the period evaluated. Conclusion: This technique provided a significant (p<0.001) improvement in the VAS and AOFAS forefoot scores at 6 months of follow-up. Between 6 and 12 months of postoperative follow-up, we did not observe a significant (p<0.05) difference in the results of the analysis due to stabilization of the condition and fracture consolidation. Although the results were considered excellent, the level of evidence of studies should be increased to effectively demonstrate the efficacy of this technique. Level of Evidence IV; Therapeutic Studies; Case Series.

Sites of Anesthetic Block of the Lateral and Medial Palmar Metacarpal Nerves in Equines of Indeterminate Breed

Background: Local anesthesia blockage at equines claudication diagnosis besides favoring the beginning of the therapy and relieving patient’s pain, it allows the identification of the specific affected region and its origin, however, if it is done incorrectly (by improper volume of anesthetics application and/or mistakenly nerve identification due to the lack of anatomic referential) it may cause inflammation, infection or even tissue necrosis. The aim was describing anatomically lateral and medial palmar metacarpal nerves in equines to improve diagnostic anesthetic block techniques on four metacarpophalangeal articulation joints of the specie.Materials, Methods & Results: A number of 20 thoracic limbs from 10 equines of indeterminate breed were used to be fixated in 10% phormaldehyde and with a marked arterial system by water solution of red dyed latex. The structures were identified by dissection, and their denomination bases on Nomina Anatomica Veterinaria (N.A.V.) by the International Committee on Veterinary Gross Anatomical Nomenclature. The study had been approved by the Board of Ethics in Animal Use of the University Center of Patos de Minas (UNIPAM), protocol n° 18/17. The lateral and medial palmar metacarpal nerves have been observed in all of the specimens originated from the deep branch of lateral palmar nerve, immediately distal to the intercarpal articulation. After its origin, the first nerve stretched ipsilaterally from the common trunk, whilst the second nerve positioned counter-lateral manner after superficially crossing the interosseus muscle. Both penetrated at the level of the mid third of the referred muscle and the metacarpal bone III and, assumed respectively a parallel medial position to the metacarpal bone IV and lateral to the metacarpal II, being intimately associated to the palmar face of the metacarpal bone III. Distally, those nerves emerged from a palmar position to a lateral and medial to the distal extremity of the metacarpal bones, corresponding and adjacent to the metacarpophalangeal articulation palmar recession, where they had finally ramified to partially innervate the associated articular capsule and the subcutaneous tissue of the region.Discussion: The lateral and medial palmar metacarpal nerves present similar origin and disposition to the above described, however, besides largely mentioned in literature, we point out here as recommended by N.A.V., no use of terms like axial and abaxial as position indicators for equine. As a part of block anesthetic diagnosis of four metacarpophalangeal articulation points, it is hereby suggested for the studied nerves desensitization, should be palpated the distal extremities of the metacarpal bones IV and II. After the identification, using thumb located from the extremity at proximal direction way, introduce the needle bilaterally for 1.5 cm downright between the above mentioned metacarpal bones and the interosseus muscle, being these latter and the flexor muscle tendons drawn in the palmar direction. Thus, it becomes valid to affirm that the technique of four-point diagnostic anesthetic block of the metacarpophalangeal articulation has been perfected for equines, and that it will limit the chances of false results on account of misplaced puncturing of nearby structures, such as, for example, the synovial recesses, mentioned as the location of the utmost gravity, hence septic synovitis may come in play.

Time-controlled adaptive ventilation (TCAV) accelerates simulated mucus clearance via increased expiratory flow rate

BackgroundVentilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care units. Distal airway mucus clearance has been shown to reduce VAP incidence. Studies suggest that mucus clearance is enhanced when the rate of expiratory flow is greater than inspiratory flow. The time-controlled adaptive ventilation (TCAV) protocol using the airway pressure release ventilation (APRV) mode has a significantly increased expiratory relative to inspiratory flow rate, as compared with the Acute Respiratory Distress Syndrome Network (ARDSnet) protocol using the conventional ventilation mode of volume assist control (VAC). We hypothesized the TCAV protocol would be superior to the ARDSnet protocol at clearing mucus by a mechanism of net flow in the expiratory direction.MethodsPreserved pig lungs fitted with an endotracheal tube (ETT) were used as a model to study the effect of multiple combinations of peak inspiratory (IPF) and peak expiratory flow rate (EPF) on simulated mucus movement within the ETT. Mechanical ventilation was randomized into 6 groups (n = 10 runs/group): group 1—TCAV protocol settings with an end-expiratory pressure (PLow) of 0 cmH2O and PHigh 25 cmH2O, group 2—modified TCAV protocol with increased PLow 5 cmH2O and PHigh 25 cmH2O, group 3—modified TCAV with PLow 10 cmH2O and PHigh 25 cmH2O, group 4—ARDSnet protocol using low tidal volume (LTV) and PEEP 0 cmH2O, group 5—ARDSnet protocol using LTV and PEEP 10 cmH2O, and group 6—ARDSnet protocol using LTV and PEEP 20 cmH2O. PEEP of ARDSnet is analogous to PLow of TCAV. Proximal (towards the ventilator) mucus movement distance was recorded after 1 min of ventilation in each group.ResultsThe TCAV protocol groups 1, 2, and 3 generated significantly greater peak expiratory flow (EPF 51.3 L/min, 46.8 L/min, 36.8 L/min, respectively) as compared to the ARDSnet protocol groups 4, 5, and 6 (32.9 L/min, 23.5 L/min, and 23.2 L/min, respectively) (p < 0.001). The TCAV groups also demonstrated the greatest proximal mucus movement (7.95 cm/min, 5.8 cm/min, 1.9 cm/min) (p < 0.01). All ARDSnet protocol groups (4–6) had zero proximal mucus movement (0 cm/min).ConclusionsThe TCAV protocol groups promoted the greatest proximal movement of simulated mucus as compared to the ARDSnet protocol groups in this excised lung model. The TCAV protocol settings resulted in the highest EPF and the greatest proximal movement of mucus. Increasing PLow reduced proximal mucus movement. We speculate that proximal mucus movement is driven by EPF when EPF is greater than IPF, creating a net force in the proximal direction.

Identification of key events in baseball hitting using inertial measurement units

Quantification of baseball hitting mechanics under game conditions help players to become successful batters and prevent injuries. Inertial measurement units (IMUs) can measure motion without any spatial restriction and are thus becoming a popular tool to investigate sports biomechanics. Biomechanical analysis of hitting requires the accurate detection of key events including “foot-off” while leaning back (FOff), “foot-on” during forward swing (FOn), and ball impact. Ten male university baseball players hit a ball suspended on a T pole five times in kick-hitting and glide-hitting styles. Three IMUs were attached on mid-pelvis and on each hand to record acceleration and orientation data. The key events identified by the three IMUs were compared with those retrieved by an optical motion capture system with force platforms. The timings of the local peak acceleration of the pelvis in the direction of the pitcher that were recorded by the IMU closely matched those of FOff and FOn events detected by the ground reaction force. Root mean square error (RMSE) between each measurement for the FOff and FOn events were 0.024 and 0.031 s, respectively. The timing of the negative peak of acceleration in the proximal direction of the hands corresponded to the impact time determined by an optical motion capture system. RMSEs for the knob and barrel-side hand were 0.009 and 0.011 s, respectively. Our results demonstrate how IMUs can be useful for analyzing baseball hitting mechanics.

Distal Ulnar Metaphyseal Wedge Osteotomy for Ulnar Abutment Syndrome.

Background Ulnar shortening osteotomy of the diaphysis is a common and effective surgical procedure for ulnar abutment syndrome. However, this procedure has some disadvantages, such as a long period until union and a relatively high nonunion rate. To overcome these disadvantages, we have developed distal ulnar metaphyseal wedge osteotomy. The purpose of this article is to describe the technique and to report its clinical results. Patients and Methods Distal ulnar metaphyseal wedge osteotomy consists of resection of the wedge fragment at the distal ulnar metaphysis, compressing the distal fragment of the ulna toward the radial-proximal direction and fixation with a Herbert type headless screw. We performed this procedure for 58 patients with ulnar abutment syndrome, and the clinical data of 43 patients who were followed for > 6 months were analyzed. We evaluated range of motion, grip strength, and HAND20 which is a validated subjective scoring system in Japan. Results All patients experienced relief from their ulnar wrist pain, and bone union was achieved within an average of 2.6 months. The range of dorsiflexion improved from 63° preoperatively to 69° postoperatively, grip strength compared with the contralateral hand improved from 77% preoperatively to 87% postoperatively, and HAND20 improved from 41.3 points preoperatively to 22.4 points postoperatively. Discussion This procedure has advantages especially in early bone union. This procedure should be taken into consideration as one of the options to treat ulnar abutment syndrome.

An Extensile Approach to the Radial Aspect of the Carpus: "The Link Incision".

The structures on the radial side of the wrist and thumb base can be approached by a longitudinal incision on the radial side of the wrist. However, longer longitudinal scars can be cosmetically unacceptable and can result in a scar contracture. It is preferable to curve longer incisions along the Langer’s skin lines to achieve better scar characteristics. Curving the incision also enables an extensile approach and provides easy access to the thumb base, radial carpus, and radial wrist joint. We describe our approach as a “Link” between the most common approaches that surgeons are familiar with; the dorsoulnar approach to the thumb metacarpophalangeal joint for ulnar collateral ligament repair and the flexor carpi radialis approach for distal radial fracture fixation. The zone between these two incisions is not as frequently approached. Our incision connects these two well established incisions and we have described a step by step approach to this unfamiliar area. This “Link zone” overlies the thumb trapeziometacarpal joint, scaphotrapeziotrapezoid joint, and the radial styloid. It contains superficial branches of the radial nerve, first extensor compartment tendons, and the deep branch of radial artery in the anatomic snuff box. The “Link incision” is an extensile approach in both the proximal and distal directions.

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae).

Our aim was to compare friction and traction forces between two burying beetle species of the genus Nicrophorus exhibiting different attachment abilities during climbing. Specifically, the interaction of adhesive hairs and claws during attachment with respect to various surface properties was investigated by using a 2 × 3 experimental design. Traction force was measured for two different surface energies (hydrophilic vs hydrophobic) varying in roughness from smooth to micro-rough to rough. Nanotribometric tests on single legs were also performed. The external morphology of the attachment devices investigated by scanning electron microscopy suggested higher intra-specific (intersexual) than inter-specific differences. Whereas differences between the two species in traction force were high on smooth surfaces, no differences could be detected between males and females within each species. With claws intact, both species showed the highest forces on rough surfaces, although N. nepalensis with clipped claws performed best on a smooth surface. However, N. nepalensis beetles outperformed N. vespilloides, which showed no differences between smooth and rough surfaces with clipped claws. Both species demonstrated poor traction forces on micro-rough surfaces. Results concerning the impact of surface polarity were inconclusive, whereas roughness more strongly affected the attachment performance in both species. Nanotribometric analyses of the fore tarsi performed on micro-rough and rough surfaces revealed higher friction in the proximal (pull) direction compared with the distal (push) direction. In these experiments, we detected neither differences in friction performance between the two species, nor clear trends concerning the influence of surface polarity. We conclude that the investigated morphological traits are not critical for the observed interspecific difference in attachment ability on smooth surfaces. Furthermore, interspecific differences in performance are only clear on smooth surfaces and vanish on micro-rough and rough surfaces. Our results suggest that even subtle differences in the adhesion-mediating secretion in closely related species might result in qualitative performance shifts.

Local cerebral hemodynamics following STA-MCA bypass in patients with symptomatic carotid occlusions

To assess changes in local hemodynamic parameters in patients with symptomatic ICA occlusions and moyamoya disease after placement of extracranial-intracranial bypass (EC-IC bypass). The study included 112 patients who underwent surgical treatment at the National Scientific and Practical Center for Neurosurgery in the period between 1999 and 2015. Of these, 105 patients had ICA occlusions, and 7 patients had moyamoya disease. During the main stage of EC-IC bypass placement, all patients were monitored for local hemodynamic parameters using intraoperative contact Doppler ultrasonography - 89 (72%) patients (72%) and flowmetry - 56 (50%)). In 33 (29%) cases, both techniques were used. Forty two patients underwent preoperative SCT perfusion to assess the degree of perfusion deficit. Grade 1 cerebrovascular insufficiency (acute oligemia) was detected in 6 patients; grade 2 perfusion deficit (persistent oligemia) was found in 25 patients; grade 3 perfusion deficit (chronic oligemia) was present in 11 patients. Measurements were performed before bypass placement: the blood flow direction and hemodynamic parameters in the cortical arteries were evaluated; and after bypass placement: blood flow values and directions in the cortical artery, proximal and distal to the bypass area, were assessed. A total of 112 EC-IC bypasses were placed without perioperative complications and deaths. Bypass functioning was confirmed in 108 (96.3%) cases; bypass thrombosis occurred in 4 (3.7%) cases. The distal blood flow direction was observed in patients with ICA occlusions (105 patients) in all cases before EC-IC bypass placement. Patients with moyamoya disease had more often the proximal blood flow direction - 5 (71%) out of 7 cases. The cerebral blood flow parameters obtained in this study differed significantly, depending on the baseline degree of perfusion deficit. The blood flow rate was minimal in patients with grade 1 cerebrovascular insufficiency. After revascularization, local hemodynamics in the cortical arteries was significantly dependent on the ability of EC-IC bypass to reverse blood flow in the proximal acceptor artery. A change in the blood flow direction was observed in 86 (77%) cases. The mean volumetric blood flow in EC-IC bypass was 34.2±5.7 mL/min. The knowledge of baseline hemodynamic parameters and their changes after revascularization plays an important role in choosing the correct surgical technique, further bypass functioning, and, as a result, improvement of the clinical outcome after surgery.

Tectonophysical Paleostress Reconstructions: Interpretation Challenges and Possible Solutions

Abstract —Paleostress inversion may be ambiguous when several markedly different local stress states are inferred for a group of outcrops. Attempts of reconstructing regional stress regimes (compressional, extensional, or strike-slip) by selecting local principal stresses of proximal directions turn out to have poor grounds. Each stress permutation (e.g., extension to compression) attendant with buildup of large irreversible strain (fault slip) requires a 5–6 kbar change in middle-crust horizontal stress and at least 50 Myr stable and uniform loading. Tectonophysical stress reconstructions for present active intracontinental orogens show heterogeneous patterns: Stress directions in uplifts are different from those in large intermontane basins and even in relatively subsided parts of mountain ranges or in adjacent uplifted zones (e.g., a plateau and a range). Paleostresses should be interpreted with reference to present stress fields in the respective areas. It is suggested to reconstruct regional stresses using the approach of L. Sim implying search for “common stress fields”. Another important technique is to trace stress changes in specific structures (large folds etc.) in the course of their evolution. The available data indicate correlation and bipolarity of stress states in large basins and uplifts.

Medical and social rehabilitation following testicular prosthesis in post-orchiectomy patients

Aim. The aim of this study was to optimize indications and techniques and to develop the optimal timing for testicular prosthesis following inversion in adolescence considering the assessment of quality of life of patients at different times following the surgery. Materials and methods. We observed 70 patients with gonadal loss following critical ischemia (torsion) at ages 11-18 years (average, 15.5 ± 2.3 years). In total, 49 patients underwent joint replacement after orchiectomy due to torsion. In 21 patients, prosthetics were preceded by orchiectomy for testicular atrophy as a result of twisting. The interval from an acute episode to joint replacement ranged from 6 months to 15 years. Three techniques for testicular prosthesis implantation were applied: prosthetics with inguinal access without suturing the scrotal entrance (n = 14); prosthetics with inguinal access with suturing the scrotal entrance by the originally developed technique (n = 34); and a prosthetic scrotum (n = 22). Patient satisfaction was assessed based on the different outcomes of testicular inversion according to the originally developed questionnaire. Results. Suturing the scrotal entrance reduces the risk of implant migration in the proximal direction due to anatomical prerequisites. Scrotal access does not have this drawback but increases the risk of inflammatory complications. The esthetic result of prosthetics depends on patient’s age during orchiectomy. Older patients tend to have better cosmetic results. The most favorable results of prosthetics are noted at the time that has passed since the turn - no more than 3 years; all unsatisfactory results are noted at the time of more than 5 years since the twist. Testicular prosthesis increases social adaptation of patients after gonadal loss and improves their quality of life. Conclusions. 1. Testicular prosthesis is an essential stage of patient rehabilitation after an orchiectomy for inversion. 2. Prosthetic inguinal access by the originally developed technique is optimal from a technical perspective and provides the most physiological standing of the implant. 3. Prosthetics results directly depend on the period following the initial operation. 4. Testicular prosthesis complications can be minimized with the accumulation of knowledge and surgical experience and their rational prevention. 5. Assessment of patients’ quality of life illustrates the necessity of gonadal prosthetics for cosmetic compensation of organ loss and psycho-emotional and social rehabilitation. (For citation: Shormanov IS, Shchedrov DN. Medical and social rehabilitation following testicular prosthesis in post-orchiectomy patients. Urologicheskie vedomosti. 2018;8(2):43-52. doi: 10.17816/uroved8243-52).

A novel REBOA system: prototype and proof of concept

Lower torso hemorrhage is a significant cause of death from injuries in combat. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been used to rescue patients successfully in the hospital setting, but its prehospital use is controversial. We designed a device that would be easy to use, safer in injured vessels, migration-resistant and amenable to a prehospital environment. We designed a novel, balloon-led device using common commercial materials. Thin latex rubber was reassembled in cylindrical conformation aligned to the shape of the aorta and invaginated into vinyl tubing. The catheter is placed into the femoral vessel, followed by expression of the balloon with CO2 inflation in a proximal direction to navigate and treat damaged pelvic vasculature, occluding the distal aorta. The system was tested on model aortas (both intact and injured cadaveric porcine aorta) with inline fluid flow and pressure monitoring to determine the maximum pressure the balloons could occlude. The device was also tested on a perfused human cadaveric model. Flow was occluded with the balloon up to an average of 561.1 ± 124.3 mm Hg. It always ruptured before causing damage to the porcine aorta and was able to occlude injured iliac vessels and proceed to occlude the distal aorta. The device was effective in occluding the distal aorta of a perfused human cadaver. This novel, high-volume, low-pressure device can occlude the distal aorta in a simulated human aorta model, cadaveric porcine model and perfused human cadaver. It can occlude fluid flow to supraphysiologic pressures. It is easy to use, migration-resistant, able to navigate and treat injured pelvic vessels, and amenable to prehospital care.

Performance control after arthroscopic arthrolysis with capsulectomy in fresh-frozen elbow joints

Posttraumatic or postoperative movement restrictions in elbow joints can often occur (including capsular contracture) and can generate everyday limitations. In persistent elbow stiffness, arthroscopic arthrolysis with removal of the dorsal and ventral capsule portions can be carried out. The purpose of this study was to assess the efficacy of arthroscopic capsulectomy by means of an in vitro anatomical study. Astandardized elbow arthroscopy with ventral and dorsal capsulectomy was performed and image-documented in fivefresh-frozen elbow specimens. Subsequently, open dissection of the elbow joint was performed to analyze the amount of residual capsule by means of photodocumentation of the specimens. Regardless of the surgeon and surgical experience, anterior and posterior remnants of the capsule remained in all specimens. Dorsal capsule strands around the standard arthroscopy portals were noticed particularly more often in the area of the high dorsolateral camera portal. An incomplete capsulectomy was seen on the ulnar side at the level of the posterior medial ligament (PML) in the immediate vicinity of the ulnar nerve. Ventrally, acapsulectomy was performed from the radial side and also the ulnar side until the brachialis muscle and additionally acomplete capsulectomy as far as the anterior medial ligament (AML) and radial collateral ligament (RCL) was achieved. The capsule was completely resected in a proximal direction. Distally, irrelevant capsular remnants were found in the region of the annular ligament and distal of the tip of the coronoid process. Arthroscopic arthrolysis can be performed with ahigh degree of radicality. The radicality must be self-critically taken into account in one's own action. The radicality of the portal change may even be higher ventrally than with an isolated column procedure. On the other hand, it must be critically considered that posteriorly, the PML cannot be adequately addressed by means of arthroscopy due to the risk of ulnar nerve injury. Portal changes might help to enable amore complete visualization of the joint capsule and may avoid leaving possibly relevant remnants of the capsule. If arelease of the PML is required, this may have to be carried out in combination with an ulnar nerve release in a mini-open technique.