Preoperative planning of lymphaticovenous anastomosis: The use of magnetic resonance lymphangiography as a complement to indocyanine green lymphography.

BACKGROUND: Lymphaticovenous anastomosis (LVA) is a surgical treatment for lymphedema that requires identification and mapping of functional lymphatic channels. This technique was performed blindly for years because of the lack of suitable methods of study. Progress in imaging techniques and the introduction of Indocyanine green lymphography (ICG-L) represented a significant advancement in lymphedema management. Magnetic resonance lymphangiography (MRL) has also helped improve knowledge about lymphedema anatomy and pathophysiology. We now present our protocol based on both ICG-L and MRL for optimal LVA preoperative planning. METHODS: A prospective study between April 2010 and June 2015 was conducted in 82 patients (77 females, mean age 45.5 years) with stage I (9.8%), II (73.2%), and III (17.0%) lymphedema. All patients underwent lymphedema surgical treatment with LVA. Surgery was planned based on preoperative information from ICG- L and MRL. RESULTS: We obtained a mean of 6.87 lymphatic locations per extremity from MRL and selected a mean of 4.04 for LVA. When MRL data coincided with ICG-L data, we found a functional lymphatic vessel in 96.9% of cases and performed LVA successfully in 91.4%. CONCLUSIONS: ICG-L and MRL are noninvasive techniques that provide images of the lymphatic system with sufficient temporal and spatial resolution to depict functional lymphatic vessels. Such knowledge is essential for preoperative planning of LVA microsurgery. We present our protocol for the approach of surgical treatment of lymphedema. This protocol represents a step forward in unifying patient selection criteria and achieving safe, effective, and rational surgery.

Detection of muscle gap by L-BIA in muscle injuries: clinical prognosis.

Sport-related muscle injury classifications are based basically on imaging criteria such as ultrasound (US) and magnetic resonance imaging (MRI) without consensus because of a lack of clinical prognostics for return-to-play (RTP), which is conditioned upon the severity of the injury, and this in turn with the muscle gap (muscular fibers retraction). Recently, Futbol Club Barcelona's medical department proposed a new muscle injury classification in which muscle gap plays an important role, with the drawback that it is not always possible to identify by MRI. Localized bioimpedance measurement (L-BIA) has emerged as a non-invasive technique for supporting US and MRI to quantify the disrupted soft tissue structure in injured muscles. OBJECTIVE: To correlate the severity of the injury according to the gap with the RTP, through the percent of change in resistance (R), reactance (Xc) and phase-angle (PA) by L-BIA measurements in 22 muscle injuries. MAIN RESULTS: After grouping the data according to the muscle gap (by MRI exam), there were significant differences in R between grade 1 and grade 2f (myotendinous or myofascial muscle injury with feather-like appearance), as well as between grade 2f and grade 2g (myotendinous or myofascial muscle injury with feather and gap). The Xc and PA values decrease significantly between each grade (i.e. 1 versus 2f, 1 versus 2g and 2f versus 2g). In addition, the severity of the muscle gap adversely affected the RTP with significant differences observed between 1 and 2g as well as between 2f and 2g. SIGNIFICANCE: These results show that L-BIA could aid MRI and US in identifying the severity of an injured muscle according to muscle gap and therefore to accurately predict the RTP.

Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (P<0.001) T2 of GR (95%), ST (65%), BFSh (51%) and BFLh (14%). After the Nordic hamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (P<0.001). Russian belt and conic-pulley exercise produced subtle (P<0.02) T2 increases of ST (9 and 6%, respectively) and BFLh (7 and 6%, respectively). Russian belt increased T2 of SM (7%). Among exercises examined, flywheel leg curl showed the most substantial hamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors.

Effects of muscle injury severity on localized bioimpedance measurements.

Muscle injuries in the lower limb are common among professional football players. Classification is made according to severity and is diagnosed with radiological assessment as: grade I (minor strain or minor injury), grade II (partial rupture, moderate injury) and grade III (complete rupture, severe injury). Tetrapolar localized bioimpedance analysis (BIA) at 50 kHz made with a phase-sensitive analyzer was used to assess damage to the integrity of muscle structures and the fluid accumulation 24 h after injury in 21 injuries in the quadriceps, hamstring and calf, and was diagnosed with magnetic resonance imaging (MRI). The aim of this study was to identify the pattern of change in BIA variables as indicators of fluid [resistance (R)] and cell structure integrity [reactance (Xc) and phase angle (PA)] according to the severity of the MRI-defined injury. The % difference compared to the non-injured contralateral muscle also measured 24-h after injury of R, Xc and PA were respectively: grade I (n = 11; -10.4, -17.5 and -9.0%), grade II (n = 8; -18.4, -32.9 and -16.6%) and grade III (n = 2; -14.1, -52.9 and -43.1%), showing a greater significant decrease in Xc (p < 0.001). The greatest relative changes were in grade III injuries. However, decreases in R, that indicate fluid distribution, were not proportional to the severity of the injury. Disruption of the muscle structure, demonstrated by the localized determination of Xc, increased with the severity of muscle injury. The most significant changes 24 h after injury was the sizeable decrease in Xc that indicates a pattern of disrupted soft tissue structure, proportional to the severity of the injury.

Usefulness of coronary artery calcium for detecting significant coronary artery disease in asymptomatic individuals.

OBJECTIVES: To confirm the value of the coronary artery calcium (CAC) score as an indicator of significant coronary artery disease (CAD) in the asymptomatic Spanish population, using noninvasive coronary angiography by multidetector computed tomography (MDCT). METHODS: This was a retrospective study of 232 asymptomatic individuals, referred for a cardiovascular health checkup that included CAC and MDCT. RESULTS: Participants' mean age was 54.6 years (SD ± 12.8); 73.3% of them were men. The mean CAC value was 117.8 (SD ± 277). The individuals with arterial hypertension, diabetes mellitus, smoking and 3 or more risk factors had significantly greater CAC scores. Some 16.4% of the participants were in the ≥75 percentile population for CAC. The MDCT identified 148 individuals (63.8%) with CAD; the coronary lesions were not significant in 116 individuals (50%) and were significant (>50% stenosis) in 32 (13.8%). The participants with diabetes, smoking and ≥3 risk vascular factors had a greater prevalence of significant stenosis. The individuals with >50% stenosis had higher CAC values (352.5 vs. 1; P<.0001), and those in the ≥75 percentile had a high percentage of significant lesions (57.9% vs. 5.2%; P<.0001). The predictors of significant CAD were a CAC score >300 (OR=10.9; 95% CI 3.35-35.8; P=.0001), belonging to the ≥75 percentile (OR=5.65; 95% CI 1.78-17.93; P=.03) and having 3 or more vascular risk factors (OR=4.19; 95% CI 1.44-12.14; P=.008). CONCLUSION: CAC quantification is an effective method for determining the extent and magnitude of CAD and delimiting the predictive capacity of traditional risk factors.

Localized bioimpedance to assess muscle injury.

Injuries to lower limb muscles are common among football players. Localized bioimpedance analysis (BIA) utilizes electrical measurements to assess soft tissue hydration and cell membrane integrity non-invasively. This study reports the effects of the severity of muscle injury and recovery on BIA variables. We made serial tetra-polar, phase-sensitive 50 kHz localized BIA measurements of quadriceps, hamstring and calf muscles of three male football players before and after injury and during recovery until return-to-play, to determine changes in BIA variables (resistance (R), reactance (Xc) and phase angle (PA)) in different degrees of muscle injury. Compared to non-injury values, R, Xc and PA decreased with increasing muscle injury severity: grade III (23.1%, 45.1% and 27.6%), grade II (20.6%, 31.6% and 13.3%) and grade I (11.9%, 23.5% and 12.1%). These findings indicate that decreases in R reflect localized fluid accumulation, and reductions in Xc and PA highlight disruption of cellular membrane integrity and injury. Localized BIA measurements of muscle groups enable the practical detection of soft tissue injury and its severity.

The best conditions for parallel stenting during EVAR: an in vitro study.

OBJECTIVES: The aim of this study is to identify which endograft, and to what degree of oversizing, in combination with what type of parallel stent, may result in the most adequate fit in a juxtarenal abdominal aneurysmal neck when using a parallel-stent technique. MATERIALS/METHODS: In-vitro silicon aneurysmal neck models of different diameters, with one side-branch, were constructed. Two different endografts (Medtronic-Endurant Abdominal Stent Graft and Gore-Excluder abdominal aortic aneurysm Endoprosthesis; three diameters each), and two stents (self-expanding Gore Viabahn Endoprosthesis and balloon-expandable Atrium Advanta V12; 6-mm diameter) were tested, applying three endograft-oversizing degrees (15%, 30% and 40%). After remodelling using the kissing-balloon technique at 37 °C, the 36 endograft-stent-oversizing combinations were scanned by computed tomography (CT). The size of the results in gutters, parallel-stent compression and main stent-graft infolding were recorded. RESULTS: Increasing oversizing (15%, 30% and 40%) significantly decreased gutter areas (11.5, 6.2, 4.3 mm(2), P < 0.001); nevertheless, main endograft infolding of most 40%-oversized stent grafts was detected, particularly with Excluder devices. Lower stent compression, but wider gutters, were observed with the Excluder when compared to Endurant stent grafts, and with V12 when compared to Viabahn parallel stents. The Endurant-Viabahn combination resulted in maximum stent compression (35%). CONCLUSIONS: Better endograft-stent apposition was achieved when using 30% endograft oversizing. Lower stent compression, but wider gutters, were observed with the Excluder stent-graft and V12 parallel stent, achieving maximum stent compression with the Endurant-Viabahn combination.

Anatomy of the temporomandibular joint.

The temporomandibular joint (TMJ), also known as the mandibular joint, is an ellipsoid variety of the right and left synovial joints forming a bicondylar articulation. The common features of the synovial joints exhibited by this joint include a fibrous capsule, a disk, synovial membrane, fluid, and tough adjacent ligaments. Not only is the mandible a single bone but the cranium is also mechanically a single stable component; therefore, the correct terminology for the joint is the craniomandibular articulation. The term temporomandibular joint is misleading and seems to only refer to one side when referring to joint function. Magnetic resonance imaging has been shown to accurately delineate the structures of the TMJ and is the best technique to correlate and compare the TMJ components such as bone, disk, fluid, capsule, and ligaments with autopsy specimens.

Multidetector-row computed tomography in the planning of abdominal perforator flaps.

An accurate preoperative evaluation of the vascular anatomy of the abdominal wall is extremely valuable in improving the surgical strategy in abdominal perforator flaps. The multidetector-row computer tomography offers thin slice coverage of extended volumes with an extremely high spatial resolution. From October 2003 to December 2004, 66 female patients had breast reconstruction surgery in our department using the deep inferior epigastric artery perforator flap. Our multidetector-row computer tomography studies were performed using a 16-detector-row computer tomography scanner. The image assessment was carried out using the following protocol: we first identified the best three perforators from each side of the abdomen. Then we conducted a three-dimensional reconstruction of the abdomen by identifying exactly where the three best perforators emerged from the rectus abdominis fascia. We then transferred the data obtained from the image to the patient using a coordinate system. In addition, we also placed the dominant perforators in the patient by using a conventional hand-held Doppler. During the operation we compared intra-operative findings, Doppler results and computer tomography outcomes. Neither false positive nor false negative results were found in the computer tomography outcome. Multidetector-row computer tomography provides us with an easy method of interpreting the virtual anatomic dissection in three dimensions. It has high sensitivity and specificity and provides a good quality evaluation of the perforator vessels. This information allows reduction of operating time and safer performance of surgery. The multidetector-row computer tomography is a highly effective tool in the preoperative study of abdominal perforator flaps.