Risk of injury to the sural nerve during posterolateral approach to the distal tibia: An ultrasound simulation study.

When surgeons operate on the foot and ankle, the most common complication that may arise is injury of the cutaneous nerves. The sural nerve (SN) is potentially at risk of being injured when treating fractures involving the distal tibia using the posterolateral approach. The aim of this study was to evaluate how differences in length and position of the surgical treatment of fractures involving the distal tibia can affect the risk of SN injury. The study involved 40 healthy volunteers (n = 80 lower limbs). Ultrasound simulation of each potential surgical incision site was used to locate the SN and to assess the risk of injury. The study showed that the SN predominantly travels more posteriorly at levels more proximal from the tip of the lateral malleolus. At these more proximal points of the SN's course, it was proven that there was an overall increased incidence of iatrogenic injury to the SN in incisions made closer to the Achilles tendon. Based on these results, a quasi 3 dimensional figure was created showing the anatomical structures of this region to identify areas at high risk for SN injury. By revealing how length and position of the surgical incision can influence the risk of SN injury, we hope to provide information to surgeons on the optimal technique to avoid iatrogenic SN injury while operating on the distal tibia via a posterolateral approach. Clin. Anat. 31:870-877, 2018. © 2018 Wiley Periodicals, Inc.

Association between low-grade chronic inflammation and depressed left atrial compliance in heart failure with preserved ejection fraction: A retrospective analysis.

BACKGROUND: A novel paradigm of diastolic heart failure with preserved ejection fraction (HFpEF) proposed the induction of coronary microvascular dysfunction by HFpEF comorbidities via a systemic pro-inflammatory state and associated oxidative stress. The consequent nitric oxide deficiency would increase diastolic tension and favor fibrosis of adjacent myocardium, which implies not only left ventricular (LV), but all-chamber myocardial stiffening. Our aim was to assess relations between low-grade chronic systemic inflammation and left atrial (LA) pressure-volume relations in real-world HFpEF patients. METHODS: We retrospectively analyzed medical records of 60 clinically stable HpEFF patients in sinus rhythm with assayed high-sensitive C-reactive protein (CRP) during the index hospitalization. Subjects with CRP >10 mg/L or coexistent diseases, including coronary artery disease, were excluded. LV and LA diameters and mitral E/E' ratio (an index of LA pressure) were extracted from routine echocardiographic records. A surrogate measure of LA stiffness was computed as the averaged mitral E/e' ratio divided by LA diameter. RESULTS: With ascending CRP tertiles, we observed trends for elevated mitral E/e' ratio (p <0.001), increased relative LV wall thickness (p = 0.01) and higher NYHA functional class (p = 0.02). The LA stiffness estimate and log-transformed CRP levels (log-CRP) were interrelated (r = 0.38, p = 0.003). On multi- variate analysis, the LA stiffness index was independently associated with log-CRP (ß ± SEM: 0.21 ± 0.07, p = 0.007) and age (ß ± SEM: 0.16 ± 0.07, p = 0.03), which was maintained upon adjustment for LV mass index and relative LV wall thickness. CONCLUSIONS: Low-grade chronic inflammation may contribute to LA stiffening additively to age and regardless of the magnitude of associated LV hypertrophy and concentricity. LA stiffening can exacerbate symptoms of congestion in HFpEF jointly with LV remodeling.

Left atrial compliance: an overlooked predictor of clinical outcome in patients with mitral stenosis or atrial fibrillation undergoing invasive management.

In the assessment of cardiovascular disease, the clinical significance of left atrial (LA) pressure-volume relations has largely been overlooked in contrast to left ventricular (LV) compliance. However, LA compliance has recently gained more attention. Net atrioventricular compliance (Cn), a joint measure of LA and LV compliance, can be calculated non-invasively by a previously validated method using parameters from standard echocardiography. Compliance measurement may be of relevance in selected clinical settings. First, subjects with low Cn are more likely to have their mitral valve area overestimated by the traditional mitral pressure half-time method. Consequently, low Cn in mitral stenosis, usually resulting from reduced LA compliance, can be mistaken for mild mitral stenosis. Second, low Cn independently predicted pulmonary hypertension and disease progression in medically treated mitral stenosis, and late cardiovascular complications after successful percutaneous mitral valvuloplasty. Decreased LA compliance also accounts for stiff LA syndrome, a rare complication of radiofrequency catheter ablation for atrial fibrillation, manifesting as otherwise unexplained heart failure with elevated LA pressure and pulmonary hypertension. Finally, depressed pre-ablation LA stiffness index, i.e. the ratio of the change in LA pressure to the corresponding change in LA volume during passive LA filling, was an independent predictor of arrhythmia recurrence. Thus, LA stiffening translates into adverse clinical outcomes in patients with mitral stenosis or atrial fibrillation undergoing interventional procedures. Whether reduced LA compliance after LA appendage occlusion can result in the LA stiff syndrome, has not been reported so far.