Learning curve and influencing factors of performing microsurgical anastomosis: a laboratory prospective study.

Despite being a critical component of any cerebrovascular procedure, acquiring skills in microsurgical anastomosis is challenging for trainees. In this context, simulation models, especially laboratory training, enable trainees to master microsurgical techniques before performing real surgeries. The objective of this study was to identify the factors influencing the learning curve of microsurgical training. A prospective observational study was conducted during a 7-month diploma in microsurgical techniques carried out in the anatomy laboratory of the school of surgery. Training focused on end-to-end (ETE) and end-to-side (ETS) anastomoses performed on the abdominal aorta, vena cava, internal carotid and jugular vein, femoral artery and vein, caudal artery, etc. of Wistar strain rats under supervision of 2 expert anatomical trainers. Objective and subjective data were collected after each training session. The 44 microsurgical trainees enrolled in the course performed 1792 anastomoses (1577 ETE, 88%, vs. 215 ETS, 12%). The patency rate of 41% was independent from the trainees' surgical background and previous experience. The dissection and the temporary clamping time both significantly decreased over the months (p < 0.001). Technical mistakes were independently associated with thrombosis of the anastomoses, as assessed by the technical mistakes score (p < 0.01). The training duration (in weeks) at time of each anastomosis was the only significant predictor of permeability (p < 0.001). Training duration and technical mistakes constituted the two major factors driving the learning curve. Future studies should try and investigate other factors (such as access to wet laboratory, dedicated fellowships, mentoring during early years as junior consultant/attending) influencing the retention of surgical skills for our difficult and challenging discipline.

Trends in Trapeziometacarpal Implant Design: A Systematic Survey Based on Patents and Administrative Databases.

Hand function is inseparably linked to the condition of the thumb. The trapeziometacarpal (TMC) joint that provides the different movements of opposition is one of the joints most affected by osteoarthritis, which causes an irreversible deformation of the bone. The ideal thumb carpometacarpal implant must restore range of movement, prevent complications, be biocompatible, and have good mechanical properties (ie, low wear, high corrosion resistance, and osteointegration properties where it is anchored in a bone). The integrity of the implant and the surrounding biological structures must be long-lasting and withstand constant stresses induced by the prosthesis. Three main types of implant systems for the thumb are currently clinically available; others are under investigation in human subjects. This systematic review is based on administrative databases, patents, the literature, and information from orthopedic companies. It provides a summary of strategies and design changes and an overview of the biomechanical characteristics of currently available carpometacarpal implants for treating osteoarthritis of the thumb.

Induced membrane technique with sequential internal fixation: use of a reinforced spacer for reconstruction of infected bone defects.

PURPOSE: To evaluate a novel sequential internal fixation strategy using a reinforced spacer for infected bone defect reconstruction by the induced membrane technique (IMT). METHODS: A retrospective case study was performed among patients treated for infected bone defects by applying this strategy. Following radical debridement, temporary stabilization was provided by a massive cement spacer combined with minimal intramedullary fixation during step 1. Definitive internal fixation was performed together with bone grafting at step 2. RESULTS: Eight patients with a mean age of 58 years were reviewed. The mean bone defect length was 8.8 cm. The spacer armature mostly consisted of elastic nails and Steinmann pins. Iterative debridement was required in one case after step 1. The mean interval between steps was 12 weeks. Definitive internal fixation was performed by intramedullary nailing (n = 4) or plating (n = 4). At a mean follow-up of 21 months, bone union was achieved in seven cases without additional bone grafting or infection recurrence. CONCLUSIONS: Sequential internal fixation using a reinforced cement spacer seems to be a valuable option for avoiding external fixation between IMT steps and limiting the recurrence of infection.

A cadaver study into the number of fasciotomies required to decompress the anterior compartment in forearm compartment syndrome.

PURPOSE: There is no typical approach for decompression of forearm compartment syndrome, due to contradictory considerations regarding the characteristics of forearm anterior compartment deep fascia. The main purpose of this study was to determine how many fasciae should be opened to fully decompress the forearm anterior compartment. Further, the compliance of the deep anterior compartment was also investigated, to strengthen our results. METHODS: An experimental study of a laboratory model of acute forearm compartment syndrome was performed. A deep forearm injection of egg white was undertaken to create an acute forearm compartment syndrome in sixteen non-embalmed human forearms from six male and two female donors. The pressure in the superficial and deep anterior compartments was recorded four times, both before and after each fasciotomy and the compliance of the deep anterior compartment was calculated for each step. RESULTS: The first incision of the superficial lamina of the deep fascia was not sufficient to decrease the elevated compartment pressure in the superficial and deep anterior compartments. Whereas the pressures decreased to near-baseline levels, following the fasciotomy of the intermuscular septum observed posterior to the flexor carpi radialis. The last incision of the deep lamina of the deep anterior fascia had no noticeable impact. These observations supported the hypothesis of high compliance of the deep anterior compartment. CONCLUSION: Two successive incisions were necessary to decompress the anterior compartment: the incision of the superficial lamina of the deep fascia and the incision of the intermuscular septum.

Perforators of the fibular artery and suprafascial network.

INTRODUCTION: Soft tissue defect on lower limb can result in an intractable wound. Surgeons resort in flaps to cover these injuries. Including fascia as in the case of a fasciocutaneous flap increases survey of the flap. Rising a perforator flap avoids to sacrifice a major vessel whence the nourishing perforator artery is born. We wanted to explore suprafascial distribution of the fibular skin perforator arteries supposing possible to find out a vascular axis composed of anastomoses of the fibular perforator vessels. MATERIALS AND METHODS: Systematic observation was carried out on ten injected legs about the fibular perforator distribution, and especially their suprafascial course. RESULTS: Dissection allowed us to raise in all specimens a large fasciocutaneous paddle including a fine arteriolar vessel connecting fibular perforators. Perforators were isolated along from the leg and we found suprafascial arteriole connecting all perforators from the fibular head to the lateral malleolus. There were a total number of 126 perforators for 10 legs. The mean length of the fibula was 32.9 cm. No perforator was located at more than 2 cm from fibular posterior border. Proximal perforators were closer to posterior fibular side than distal perforators. We found that fibular perforators clustered in the middle and upper third of the leg. CONCLUSION: This study proves the real existence of a microvascular suprafascial axis formed by fibular perforator anastomoses and stretching over the entire length of the fibula, from the fibular head to the distal tip of the lateral malleolus. This suprafascial vascular axis could be an anatomical basis for a fasciocutaneous fibular flap.

Dual-acting biofunctionalised scaffolds for applications in regenerative medicine.

Off the shelf scaffolds for replacing ultra-small diameter vascular grafts are valuable for reconstruction of diseased or damaged vessels. The limitations for such grafts include optimal handling with ready availability of varied lengths of grafts, graft patency with the ability to replace the function of active cellular mechanisms and adequate mechanical properties to maintain physicochemical function. We used a well-established, solvent casting method for potential tissue replacement scaffold fabrication with incorporated bioactive molecules, which we have previously explored to confer haemocompatibility. These grafts were tested in-vivo within the abdominal aorta of 10 Wistar rats and the patency was clinically and echographically evaluated. Haemocompatibility and endothelialisation were assessed on explants. Biofunctionalised scaffolds were also grafted subcutaneously and intraperitoneally to evaluate integration, inflammation and angiogenesis reactions. The potential wider applications of this dual acting scaffold were evaluated for its interactions with human dermal fibroblasts as well as bronchial epithelial cells. Physicochemical property evaluation of the functionalised grafts has clarified the mechanical strength and permeability. This study confirmed the microsurgical suturability of tubular grafts and graft patency of functionalized scaffolds. The study demonstrated the potential of a dual acting biofunctionalised scaffold's use for a wide range of tissue engineering applications where micro-porous, yet impermeable scaffolds are needed.

Finger reconstruction using induced membrane technique and ulnar pedicled forearm flap: a case report.

INTRODUCTION: Injuries referred to as "rollover hands" are associated with multiple and complex lesions of the dorsal aspect of the hand. We present a case of a multitissular reconstruction following a severe injury of the dorsum of the fingers in a 45-year-old woman. MATERIALS AND METHODS: The bone loss reconstruction was performed in two stages using the Masquelet induced membrane technique. In the first stage, a cement spacer was inserted into the phalanx bone defects. For the second stage, the membrane induced by the foreign-body reaction was opened, the spacer was removed, and an autologous cancellous bone graft was inserted into the defects. The skin coverage was obtained using a reverse ulnar artery forearm pedicled flap. The digits were covered jointly. Three surgical procedures over the course of a 2-month period were required to desyndactylize the fingers and to defat the flap. RESULTS: At the 2-year follow-up examination, the patient exhibited good integration of their hand use in daily living. The esthetic result was deemed to be satisfactory. Definitive bone consolidation occurred 4 months after the second stage. CONCLUSIONS: Rollover hands are typically a challenge for both the patient and the hand surgeon. The risk of septic complications, as well as the need for several stages of surgical reconstruction, makes the Masquelet technique particularly attractive for the treatment of phalanx bone defects consecutive to rollover injuries.

Update: Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass.

After the publication of our paper Dunlop et al. "Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass", we became aware of further data correlating left ventricular (LV) mass index at baseline and their corresponding mass at 12 months, using cardiac magnetic resonance imaging (MRI) in patients on hemodialysis. The original published sample size for the SoLID trial of 118 was a conservative estimate, calculated using analysis of covariance and a within person Pearson's correlation for LV mass index of 0.75. New data communicated to the SoLID trial group has resulted in re-calcuation of the sample size, based upon a within person Pearson's correlation of 0.8 but otherwise unchanged assumptions. As a result, the SoLID trial will now recruit 96 participants.

[François Humbert, an unknown orthopedist, initiator of cures for the "lame"]. / François Humbert, orthopédiste méconnu, initiateur du traitement curatif des "boiteux".

François Humbert (1776-1850) created in 1817 the first French orthopaedic institution, at a great turning point in orthopedics. Interested in "lame people" and "hunchbacks", he treated congenital hip dislocation and scoliosis, for about 30 years. Humbert's medical practice illustrated very well the deep transformation which occured in orthopedics at the beginning of the 19th century. As testimonies of Humbert's work, there are the books he published, his Memoirs, some buildings of his institution which have been reconverted into houses, but above all thirty-eight models of his "machines". In spite of the fact that he was the first to consider congenital hip dislocation like a curable disease, his work quickly became unknown after his death.

Rationale and design of the Myocardial Microinjury and Cardiac Remodeling Extension Study in the Sodium Lowering in Dialysate trial (Mac-SoLID study).

BACKGROUND: The Sodium Lowering in Dialysate (SoLID) trial is an ongoing a multi-center, prospective, randomised, single-blind (assessor), controlled, parallel assignment clinical trial, enrolling 96 home and self-care hemodialysis (HD) patients from 7 centers in New Zealand. The trial will evaluate the hypothesis that lower dialysate [Na+] during HD results in lower left ventricular (LV) mass. Since it's inception, observational evidence has suggested increased mortality risk with lower dialysate [Na+], possibly due to exacerbation of intra-dialytic hypotension and subsequent myocardial micro-injury. The Myocardial Micro-injury and Cardiac Remodeling Extension Study in the Sodium Lowering In Dialysate Trial (Mac-SoLID study) aims to determine whether lower dialysate [Na+] results in (i) increased levels of high-sensitivity Troponin T (hsTnT), a well-established marker of intra-dialytic myocardial micro-injury in HD populations, and (ii) increased fixed LV segmental wall motion abnormalities, a marker of recurrent myocardial stunning and micro-injury, and (iii) detrimental changes in LV geometry due to maladaptive homeostatic mechanisms. METHODS/DESIGN: The SoLID trial and the Mac-SoLID study are funded by the Health Research Council of New Zealand. Key exclusion criteria: patients who dialyse > 3.5 times per week, pre-dialysis serum sodium <135 mM, and maintenance haemodiafiltration. In addition, some medical conditions, treatments or participation in other dialysis trials that contraindicate the study intervention or confound its effects, will be exclusion criteria. The intervention and control groups will receive dialysate sodium 135 mM and 140 mM respectively, for 12 months. The primary outcome measure for the Mac-SOLID study is repeated measures of [hsTnT] at 0, 3, 6, 9, and 12 months. The secondary outcomes will be assessed using cardiac magnetic resonance imaging (MRI), and comprise LV segmental wall motion abnormality scores, LV mass to volume ratio and patterns of LV remodeling at 0 and 12 months. DISCUSSION: The Mac-SoLID study enhances and complements the SoLID trial. It tests whether potential gains in cardiovascular health (reduced LV mass) which low dialysate [Na+] is expected to deliver, are counteracted by deterioration in cardiovascular health through alternative mechanisms, namely repeated LV stunning and micro-injury. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry number: ACTRN12611000975998.

Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass.

BACKGROUND: The current literature recognises that left ventricular hypertrophy makes a key contribution to the high rate of premature cardiovascular mortality in dialysis patients. Determining how we might intervene to ameliorate left ventricular hypertrophy in dialysis populations has become a research priority. Reducing sodium exposure through lower dialysate sodium may be a promising intervention in this regard. However there is clinical equipoise around this intervention because the benefit has not yet been demonstrated in a robust prospective clinical trial, and several observational studies have suggested sodium lowering interventions may be deleterious in some dialysis patients. METHODS/DESIGN: The Sodium Lowering in Dialysate (SoLID) study is funded by the Health Research Council of New Zealand. It is a multi-centre, prospective, randomised, single-blind (outcomes assessor), controlled parallel assignment 3-year clinical trial. The SoLID study is designed to study what impact low dialysate sodium has upon cardiovascular risk in dialysis patients. The study intends to enrol 118 home hemodialysis patients from 6 sites in New Zealand over 24 months and follow up each participant over 12 months. Key exclusion criteria are: patients who dialyse more frequently than 3.5 times per week, pre-dialysis serum sodium of <135 mM, and maintenance hemodiafiltration. In addition, some medical conditions, treatments or participation in other dialysis trials, which contraindicate the SoLID study intervention or confound its effects, will be exclusion criteria. The intervention and control groups will be dialysed using dialysate sodium 135 mM and 140 mM respectively, for 12 months. The primary outcome measure is left ventricular mass index, as measured by cardiac magnetic resonance imaging, after 12 months of intervention. Eleven or more secondary outcomes will be studied in an attempt to better understand the physiologic and clinical mechanisms by which lower dialysate sodium alters the primary end point. DISCUSSION: The SoLID study is designed to clarify the effect of low dialysate sodium upon the cardiovascular outcomes of dialysis patients. The study results will provide much needed information about the efficacy of a cost effective, economically sustainable solution to a condition which is curtailing the lives of so many dialysis patients. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry number: ACTRN12611000975998.

The flexor digitorum longus muscle flap for the reconstruction of soft-tissue defects in the distal third of the leg: anatomic considerations and clinical applications.

Soft-tissue defects of the distal third of the leg are common occurrences in trauma centers. The authors present the anatomic basis and their clinical experience using the flexor digitorum longus muscle flap. Ten cadaver specimens were dissected to evaluate the potential use of this flap for soft-tissue coverage in the lower third of the leg. Eleven patients underwent a soft-tissue reconstruction in the distal third of the leg with this flap. The average size of the defect covered by this flap was 11.3 cm. This transfer flap was used in 7 cases exclusively or in combination in 4 cases. No functional deficit and good plastic result were observed in all cases. Ease of elevation and reliability has made this transfer flap the procedure of choice for small soft-tissue defects over the proximal portion of the distal tibia in our institution.

The mini postero-postero-lateral mini incision in total hip arthroplasty.

PURPOSE: Mini invasive incisions in THA and femoral hip prostheses tend to minimise healing and recovery time. We have used a very posterior approach with technical modifications and precise skin landmarks to decrease surgical complexity, and we describe this experience here. METHODS: From 2010 to 2012, 140 patients aged 79 years (range 53-93 years) were operated upon by the same surgeon in a continuous series using the same minimally invasive skin incision and six different types of implants. The incision was very posterior in the hip allowing direct visualisation of the acetabulum in the hip flexion position and visualisation of the femoral shaft extremity in a leg flexion position. RESULTS: The mean operating time was 100 minutes (range 75-110 min). Estimated blood loss was 385 cc (20-585 cc). Twenty-six patients had blood transfusion. The mean hospital stay was 6.8 days (5-20 days) including the time waiting for a rehabilitation centre. No operative complications related to the technique were recorded. On the postoperative radiograph, the femoral stem was aligned with the femoral axis within 3° in all patients. The mean acetabular angle to the ground plane was 40° (35-48°). No patient had a leg length discrepancy of more than four millimetres. The mean skin incision length was seven centimetres (six to eight centimetres). All patients were seen at the clinic after six weeks and the data were unchanged at this time point. CONCLUSION: The method and skin landmarks we describe appear to be a safe way to perform minimally invasive total hip replacement.

MQM1, a bacteriophage infecting strains of Aeromonas salmonicida subspecies salmonicida carrying Prophage 3.

Aeromonas salmonicida subsp. salmonicida is a Gam-negative bacterium responsible for furunculosis in fish. Because this aquatic bacterial pathogen has a rich reservoir of antibiotic-resistant genes, it is essential to investigate antibacterial alternatives, including the use of phages. Yet, we have previously demonstrated the inefficiency of a phage cocktail designed against A. salmonicida subsp. salmonicida strains due to a phage resistance phenotype associated to a prophage, namely Prophage 3. To bypass this resistance, one of the solutions is to isolate novel phages capable of infecting Prophage 3-bearing strains. Here we report on the isolation and characterization of the new virulent phage vB_AsaP_MQM1 (or MQM1), which is highly specific to A. salmonicida subsp. salmonicida strains. Phage MQM1 inhibited the growth of 01-B516, a strain carrying Prophage 3, including when combined to the previous phage cocktail. MQM1 infected 26 out of the 30 (87%) Prophage 3-bearing strains tested. Its linear dsDNA genome contains 63,343 bp, with a GC content of 50.2%. MQM1 genome can encode 88 proteins and 8 tRNAs, while no integrase or transposase-encoding genes were found. This podophage has an icosahedral capsid and a non-contractile short tail. We suggest that MQM1 may be a good addition to future phage cocktails against furunculosis to resolve the Prophage 3-resistance issue.

Anatomical variations in the sensory innervation of the dorsal surface of the first digit space, a cadaveric study with clinical consequences.

INTRODUCTION: Radial nerve palsy is a classical complication of a humeral shaft fracture. In clinical practice, motor palsy of the radial nerve is sometimes observed without an abnormality felt in the sensory territory. HYPOTHESIS: We hypothesised that this dissociation between sensory and motor involvement is related to anatomical variations of the sensory innervation of the dorsal surface of the first digit space, thus, we decided to study the nature and frequency of these variations. MATERIAL AND METHOD: A cadaveric study was conducted on 24 upper limbs to analyse the truncal origin of the sensory branches innervating the dorsal surface of the first digit space. RESULTS: The sensory branch of the radial nerve (SBRN) participated in the innervation of the dorsal surface of the first digit space in 22 limbs, an anatomical variation was present in 2 cases with a mixed innervation by the SBRN and the lateral cutaneous nerve of forearm (LCNF) in 1 case and singular innervation by LCNF, with no SBRN involvement, in 1 case. Communications between SBRN and LCNF were found in 7 cases. DISCUSSION: Pure motor radial damage, without a sensory deficit of the dorsal surface of the first digit space, does not preclude a complete traumatic injury of the radial nerve. The sensory innervation of this region can be relayed by a branch of the LCNF. LEVEL OF EVIDENCE: IV; cadaveric study.

Questions about Using the Induced Membrane Technique to Manage Cases of Congenital Tibial Pseudarthrosis.

The induced membrane technique is an innovative approach for repairing critical bone defects and has been applied recently in patients with congenital pseudarthrosis of the tibia (CPT). CPT is frequently associated with neurofibromatosis type 1 (NF1). Here, we briefly describe the clinical results of the induced membrane technique in NF1-deficient patients with CPT and in an animal model of CPT. Furthermore, we discuss the hypotheses used to explain inconsistent outcomes for the induced membrane technique in CPT-especially when associated with NF1.

Corrigendum: Safety of Bottle-Feeding Under Nasal Respiratory Support in Preterm Lambs With and Without Tachypnoea.

[This corrects the article DOI: 10.3389/fphys.2021.785086.].

Conventional vs high-frequency ventilation for weaning from total liquid ventilation in lambs.

OBJECTIVE: To compare conventional gas ventilation (GV) and high-frequency oscillatory ventilation (HFOV) for weaning from total liquid ventilation (TLV). METHODS: Sixteen lambs were anesthetized. After 1 h of TLV with perflubron (PFOB), they were assigned to either GV or HFOV for 2 h. Oxygen requirements, electrical impedance tomography and videofluoroscopic sequences, and respiratory system compliance were recorded. RESULTS: The lambs under GV needed less oxygen at 20 min following TLV (40 [25, 45] and 83 [63, 98]%, p = 0.001 under GV and HFOV, respectively). During weaning, tidal volume distribution was increased in the nondependent regions in the GV group compared to baseline (p = 0.046). Furthermore, residual PFOB was observed in the most dependent region. No air was detected by fluoroscopy in that region at the end of expiration in the GV group. CONCLUSION: GV offers a transient advantage over HFOV with regards to oxygenation for TLV weaning.

[The anatomy lesson of Doctor Tulp]. / La Leçon d'Anatomie du Docteur Tulp.

The Dr Tulp's Anatomy Lesson is one of Rembrandt's most famous paintings. Analysis of scene suggest that Dr Tulp is demonstrating the action of the flexor digitorum superficialis muscle on the flexion of the fingers PIP joints. Rembrandt's painting is a true lesson of the connection between an anatomic structure and a function. It also bears witnesse of the intellectual atmosphere of the 17th centrury, centered on a new theory of movement, and symbolizes an epistemological break with the descriptive anatomy of Vesalius.

Safety of Bottle-Feeding Under Nasal Respiratory Support in Preterm Lambs With and Without Tachypnoea.

Aim: Convalescing preterm infants often require non-invasive respiratory support, such as nasal continuous positive airway pressure or high-flow nasal cannulas. One challenging milestone for preterm infants is achieving full oral feeding. Some teams fear nasal respiratory support might disrupt sucking-swallowing-breathing coordination and induce severe cardiorespiratory events. The main objective of this study was to assess the safety of oral feeding of preterm lambs on nasal respiratory support, with or without tachypnoea. Methods: Sucking, swallowing and breathing functions, as well as electrocardiogram, oxygen haemoglobin saturation, arterial blood gases and videofluoroscopic swallowing study were recorded in 15 preterm lambs during bottle-feeding. Four randomly ordered conditions were studied: control, nasal continuous positive airway pressure (6 cmH2O), high-flow nasal cannulas (7 L•min-1), and high-flow nasal cannulas at 7 L•min-1 at a tracheal pressure of 6 cmH2O. The recordings were repeated on days 7-8 and 13-14 to assess the effect of maturation. Results: None of the respiratory support impaired the safety or efficiency of oral feeding, even with tachypnoea. No respiratory support systematically impacted sucking-swallowing-breathing coordination, with or without tachypnoea. No effect of maturation was found. Conclusion: This translational physiology study, uniquely conducted in a relevant animal model of preterm infant with respiratory impairment, shows that nasal respiratory support does not impact the safety or efficiency of bottle-feeding or sucking-swallowing-breathing coordination. These results suggest that clinical studies on bottle-feeding in preterm infants under nasal continuous positive airway pressure and/or high-flow nasal cannulas can be safely undertaken.