Removal Notice to 'Neurosurgical Steps and Lessons Learned in Final Separation of Three-Years-Old Craniopagus Twins' [World Neurosurgery (2022) 18924].

This article has been removed: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been removed at the request of the Editor-in-Chief because the authors did not have authorised consent from the legal representatives of the patients to publish the details of their case.

Impact of Sex and Exercise on Femoral Artery Function: More Favorable Adaptation in Male Rats.

Blood flow increases in arteries of the skeletal muscles involved in active work. Our aim was to investigate the gender differences as a result of adaptation to sport in the femoral arteries. Vascular reactivity and histology of animals were compared following a 12-week swimming training. Animals were divided into sedentary male (MS), trained male (MTr), sedentary female (FS), and trained female (FTr) groups. Isolated femoral artery rings were examined by wire myography. Contraction induced by phenylephrine (Phe) did not differ between the four groups. The contractile ability in the presence of indomethacin (INDO) was decreased in both sedentary groups. However, we found a specific cyclooxygenase-2 (COX-2) role only in FS rats. After exercise training, we observed increased vasoconstriction in both sexes, when nitro-L-arginine methyl ester (L-NAME) was present. The COX-dependent vasoconstriction effect disappeared in MTr animals, and the COX-2-dependent vasoconstriction effect disappeared in FTr ones. Relaxation was reduced significantly, when L-NAME was present in MTr animals compared to in FTr rats. The training was associated with greater endothelial nitric oxide synthase (eNOS) protein expression in males, but not in females. The present study proves that there are gender differences regarding adaptation mechanisms of musculocutaneous arteries to sports training. In males, relaxation reserve capacity was markedly elevated compared to in females.

Additive damage in the thromboxane related vasoconstriction and bradykinin relaxation of intramural coronary resistance arterioles in a rodent model of andropausal hypertension.

Hypertension and andropause both accelerate age-related vascular deterioration. We aimed to evaluate the effects of angiotensin-II induced hypertension and deficiency of testosterone combined regarding the resistance coronaries found intramurally. Four male groups were formed from the animals: control group (Co, n = 10); the group that underwenr orchidectomy (ORC, n = 13), those that received an infusion of angiotensin-II (AII, n = 10) and a grous that received AII infusion and were also surgically orchidectomized (AII + ORC, n = 8). AII and AII + ORC animals were infused with infusing angiotensin-II (100 ng/min/kg) using osmotic minipumps. Orchidectomy was perfomed in the ORC and the AII + ORC groupsto establish deficiency regarding testosterone. Following four weeks of treatment, pressure-arteriography was performed in vitro, and the tone induced by administration of thromboxane-agonist (U46619) and bradykinin during analysis of the intramural coronaries (well-known to be resistance arterioles) was studied. U46619-induced vasoconstriction poved to be significantly decreased in the ORC and AII + ORC groups when compared with Co and AII animals. In ORC and AII + ORC groups, the bradykinin-induced relaxation was also significantly reduced to a greater extent compared to Co and AII rats. Following orchidectomy, the vasocontraction and vasodilatation capacity of blood vessels is reduced. The effect of testosterone deficiency on constrictor tone and relaxation remains pronounced even in AII hypertension: testosterone deficiency further narrows adaptation range in the double noxa (AII + ORC) group. Our studies suggest that vascular changes caused by high blood pressure and testosterone deficiency together may significantly increase age-related cardiovascular risk.

Neurosurgical Steps and Lessons Learned in Final Separation of 3-Year-Old Craniopagus Twins.

The only published paper1 describing the separation of the conjoined twins did not describe the novel steps and techniques of the microsurgery part, which lasted 26 hours. That paper did not include the neurosurgical video, either. The massive intracerebral hemorrhage that occurred on postoperative day 33 was not reported, and its potential causes have not been scrutinized. The strategy of final separation was developed during day-by-day microsurgical practice on cadavers and did lead us to novel surgical solutions as the introduction of the application of hinge and distractors. One of the twins advanced to GOS 5 status during first 5 postoperative months. The other twin slowly advanced to GOS 3 status and remained at that functional level. The latter suffered the massive brain hemorrhage on postoperative day 33, which led to delayed rehabilitation and interfered with a potentially better outcome. The thorough analysis of the potential causative factors revealed the possible pathophysiologic mechanism behind that complication.2 Two major factors have been identified, one of which is the traction-related traumatic brain injury that evolved during supine position. Another probable theory is the lack of sufficient reconstruction of the posterior part of the skull, which caused a recurring tactile microtrauma of the brain due to the supine position. The hemorrhage may have been facilitated by the fact that their coagulation tests were on the lower edge of normal parameters. It was a mistake that this part of the surgery was not performed by the neurosurgeons who designed it and practiced extensively on fresh cadavers using 3-dimensional models. Sufficient cranioplasty was performed 3 months later. It is impossible to say with certainty the cause of the hemorrhage, since there may have been other unknown causes (e.g., blood pressure spike). As a contributing factor, congestion of the veins is also possible.3 We concluded that closer monitoring, a stricter management of the interdisciplinary team work, and realizing the seriousness of the lack of sufficient structural support earlier could have prevented this unfortunate complication. In a similar case we advise future professionals to use a halo ring postoperatively for posterior protection until a sufficient cranioplasty can safely be done.

Sex differences in rat renal arterial responses following exercise training.

During aerobic exercise, hemodynamic alterations occur. Although blood flow in skeletal muscle arteries increases, it decreases in visceral vessels because of mesenterial vasoconstriction. However, maintaining renal blood flow during intensive sport is also a priority. Our aim was to investigate the changes of vascular reactivity and histology of isolated renal artery of male and female rats in response to swim training. Wistar rats were distributed into four groups: male sedentary (MSed), male trained (MTr), female sedentary (FSed), and female trained (FTr). Trained animals underwent a 12-wk-long intensive swimming program. Vascular function of isolated renal artery segments was examined by wire myography. Phenylephrine-induced contraction was lower in FSed than in MSed animals, and it was decreased by training in male but not in female animals. Inhibition of cyclooxygenases by indomethacin reduced contraction in both sedentary groups, and in MTr but not in FTr animals. Inhibition of nitric oxide production increased contraction in both trained groups. Acetylcholine induced relaxation was similar in all experimental groups showing predominant NO-dependency. Elastin and smooth muscle cell actin density was reduced in female rats after aerobic training. This study shows that, as a result of a 12-wk-long training, there are sex differences in renal arterial responses following exercise training. Swimming moderates renal artery vasoconstriction in male animals, whereas it depresses elastic fiber and smooth muscle actin density in females.NEW & NOTEWORTHY We provided the first detailed analysis of the adaptation of the renal artery after aerobic training in male and female rats. As a result of a 12-wk-long training program, the pharmacological responses of renal arteries changed only in male animals. In phenylephrine-induced contraction, cyclooxygenase-mediated vasoconstriction mechanisms lost their significance in female rats, whereas NO-dependent relaxation became a significant contraction reducing factor in both sexes. Early structural changes, such as reduced elastin and smooth muscle cell actin evolves in females.

Network analysis of the left anterior descending coronary arteries in swim-trained rats by an in situ video microscopic technique.

BACKGROUND: We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy. METHODS: Thirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 µm in diameter were studied using divided 50-µm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry. RESULTS: The LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-µm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-µm vessels appeared unusually close to the orifice. CONCLUSIONS: Physical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.

Effects of Testosterone Deficiency and Angiotensin II-Induced Hypertension on the Biomechanics of Intramural Coronary Arteries.

BACKGROUND: Andropause and hypertension also increase the risk of coronary artery damage. AIM: To investigate the effect of testosterone deficiency and hypertension on intramural coronary vessels. METHODS: 4 groups of 8-week-old Sprague-Dawley rats were studied: control male (Co, n=10), orchidectomized male (OCT, n=13), angiotensin (AII) hypertensive male (AII, n=10), and AII hypertensive and OCT (AII + OCT, n=8). Surgical orchidectomy was performed, and an osmotic minipump was inserted for chronic angiotensin II infusion (100 ng/min/kg). After 4 weeks, spontaneous tone and biomechanical properties of the intramural coronary resistance artery were investigated in vitro, by pressure microarteriography. OUTCOMES: Morphology and biomechanics of the intramural coronaries were evaluated: the outer diameter, wall thickness-to-lumen diameter ratio, and tangential wall stress in the contracted and relaxed states. RESULTS: The outer diameter was reduced in OCT and AII + OCT groups (on 50 mmHg 315 ± 20 Co; 237 ± 21 OCT; 291 ± 16 AII, and 166 ± 12 µm AII + OCT). The increased wall thickness-to-lumen diameter ratio resulted in lower tangential wall stress in AII + OCT rats (on 50 mmHg 19 ± 2 Co; 24 ± OCT; 26 ± 5 AII, and 9 ± 1 kPa AII + OCT). Spontaneous tone was increased in the hypertensive rats (AII and AII + OCT groups) (on 50 mmHg 7.7 ± 1.8 Co; 6.1 ± 1.4 OCT; 14.5 ± 3.0 AII, and 17.4 ± 4.1 % AII + OCT). CLINICAL IMPLICATIONS: Andropause alone can be considered as a cardiovascular risk factor that will further exacerbate vascular damage in hypertension. STRENGTHS & LIMITATIONS: A limitation of our study is that it was performed on relatively young rats, and the conclusions might not apply to coronary remodelling in older animals with slower adaptation processes. CONCLUSIONS: Testosterone deficiency and hypertension damage the mechanical adaptation of the vessel wall additively: double noxa caused inward eutrophic remodeling and increased tone. Jósvai A, Török M, Mátrai M, et al. Effects of Testosterone Deficiency and Angiotensin II-Induced Hypertension on the Biomechanics of Intramural Coronary Arteries. J Sex Med 2020;17:2322-2330.

Long-term exercise results in morphological and biomechanical changes in coronary resistance arterioles in male and female rats.

BACKGROUND: Biomechanical remodeling of coronary resistance arteries in physiological left ventricular hypertrophy has not yet been analyzed, and the possible sex differences are unknown. METHODS: Wistar rats were divided into four groups: male and female sedentary controls (MSe and FSe) and male and female animals undergoing a 12-week intensive swim training program (MEx and FEx). On the last day, the in vitro contractility, endothelium-dependent dilatation, and biomechanical properties of the intramural coronary resistance arteries were investigated by pressure microarteriography. Elastica and collagen remodeling were studied in histological sections. RESULTS: A similar outer radius and reduced inner radius resulted in an elevated wall to lumen ratio in the MEx and FEx animals compared to that in the sedentary controls. The wall elastic moduli increased in the MEx and FEx rats. Spontaneous and TxA2 agonist-induced tone was increased in the FEx animals, whereas endothelium-dependent relaxation became more effective in MEx rats. Arteries of FEx rats had stronger contraction, while arteries of MEx animals had improved dilation. CONCLUSIONS: According to our results, the coronary arterioles adapted to an elevated load during long-term exercise, and this adaptation depended on sex. It is important to emphasize that in addition to differences, we also found many similarities between the sexes in the adaptive response to exercise. The observed sport adaptation in the coronary resistance arteries of rats may contribute to a better understanding of the physiological and pathological function of these arteries in active and retired athletes of different sexes.

Transpedicular direct osteosynthesis of hangman's fracture from a mini-open exposure as a less invasive procedure: A technical note.

This surgical technical case report presents initial clinical experience and preliminary results with a less invasive surgical solution for selected hangman's fracture. A well-known stabilization technique (i.e. direct transpedicular osteosynthesis) was applied through a minimally invasive small incision transmuscular posterior approach guided by a standard C-arm fluoroscopy. This mini-open approach to C2 vertebra allows similar dissection, visualization of the bony landmarks, visual control of the transpedicular screw path drilling, tapping and screw insertion to the standard posterior cervical spine approach. At the same time it has the benefits of less invasive procedures.