Charlson score as a single pertinent criterion to select candidates for active surveillance among patients with small renal masses

Purpose

The aim of the study was to assess the outcome after nephron-sparing surgery (NSS) of patients with small renal masses (SRMs) who would have been eligible for active surveillance (AS).

Methods

Data were collected retrospectively for 758 patients who underwent NSS over a 5-year period. Outcomes were assessed in two groups of patients who were eligible for AS according to different criteria. Group 1 criteria were as follows: age >75 years, renal mass ≤4 cm, significant comorbidities [Charlson Comorbidity Index (CCI) >2]. Group 2 criteria were as follows: any SRM ≤ 4 cm regardless of age, severe comorbidities with a 10-year mortality risk >50 % (CCI > 4). The two groups were not compared statistically because some patients were included in both.

Results

Fifty-five patients (7.3 %) were included in Group 1 and 62 (8.2 %) in Group 2. There was a significant proportion of benign tumours in Group 1 (N = 6; 11 %) and Group 2 (N = 6; 10 %). Six (11 %) positive margins were observed in Group 1 and 8 (13 %) in Group 2. The 2- and 5-year recurrence-free survival rates were 100 and 77.4 %, respectively, in Group 1, and 88.5 and 79.6 % in Group 2. The 2- and 5-year overall survival rates were 100 and 74.7 % in Group 1, and 96.7 and 78.1 % in Group 2.

Conclusions

The majority of patients with SRMs who would have been eligible for AS had no recurrence after initial tumour removal. In these patients, a CCI > 4 appeared to be a pertinent criterion to identify those patients less likely to benefit from immediate surgery.     

Brief review: Neuraxial analgesia in refractory malignant pain

Purpose

This narrative review aims to inform health care practitioners of the current literature surrounding the use of intrathecal (IT) and epidural analgesia in cancer patients with refractory pain at end of life. Topics discussed and reviewed include: patient selection, treatment planning, procedure, equipment, medications, complications, policies and procedures, as well as directions for future research.

Principal findings

Cancer pain is inadequately treated in an estimated 10% of patients with malignant pain despite the implementation of the World Health Organization three-step analgesic ladder. This has prompted some to advocate for the addition of a fourth step that would include neuraxial interventions. There is moderate evidence supporting the safety and efficacy of IT drug therapy in cancer patients with refractory pain. A detailed assessment and interdisciplinary team approach is necessary to develop and implement care plans for patients requiring neuraxial analgesia. Neuraxial analgesia can significantly improve pain and reduce side effects, but this must be balanced against the increased complexity of care and the risk of uncommon but serious complications.

Conclusion

Neuraxial drug delivery gives clinicians more options to manage refractory pain at end of life and should be offered to patients with intractable cancer pain. Teams should be interprofessional with clear delineation of roles and responsibilities. They should discuss advanced discharge planning with the patient prior to implantation as well as provide on-call support.     

Use of near infrared spectroscopy to detect impaired tissue oxygen saturation in patients with complex regional pain syndrome type 1

Purpose

Deep tissue hypoxia has been hypothesized in the pathogenesis of complex regional pain syndrome type 1 (CRPS 1) for some patients. The purpose of this study was to determine if near-infrared spectroscopy (NIRS) could detect differences in deep tissue oxygen saturation (StO₂) and microcirculatory function in the hands of patients with CRPS 1.

Methods

Tissue oxygen saturation was evaluated at baseline and during an ischemia reperfusion challenge using vascular occlusion testing (VOT) in affected vs unaffected hands of patients with unilateral upper limb CRPS 1. A non-randomized experimental study design was used with baseline StO₂ as the primary outcome measure. Secondary outcome measures were occlusion and reperfusion slopes from VOT. Values were compared with the unaffected, contralateral hand and with the dominant and non-dominant hands of sex and age-matched volunteers. Correlations between values derived from NIRS and measures of pain and function from the Brief Pain Inventory (BPI) and the Disability of the Arm, Shoulder and Hand (DASH) questionnaires were explored.

Results

Independent of handedness, the baseline StO₂ of the affected hands of ten CRPS 1 patients was significantly lower than that of their unaffected hands (?5.8%; 95% confidence interval [CI] ?10.6 to ?1.0; P = 0.02). The baseline StO₂ of affected CRPS 1 hands was also significantly lower than the non-dominant hands of ten volunteers (?7.3%; 95% CI ?12.4 to ?2.3; P = 0.007). Differences in VOT occlusion and reperfusion slopes did not reveal changes that could be uniquely attributed to CRPS 1. No significant correlations were detected between values derived from VOT and values for pain and function obtained from BPI and DASH questionnaires for patients with CRPS 1.

Conclusions

Hands of patients affected by CRPS 1 of the upper limb showed significantly lower StO₂ compared with their unaffected contralateral hand as well as the hands of control subjects. This trial was registered at: ClinicalTrials.gov: NCT01586377.     

Parastomal hernia repair with a 3-D mesh device and additional flat mesh repair of the abdominal wall

Purpose

Parastomal hernias (PSHs) have been a major clinical problem. The aim of this study was to evaluate a new method of PSH repair in combination with an additional flat mesh reinforcement of the abdominal wall.

Methods

In a pilot case series, seven patients suffering from complex PSHs (≥5 cm diameter and/or recurrence) underwent surgery and were treated by intraperitoneal onlay technique (IPOM) with a synthetic 3-D funnel-shaped mesh implant. The demographics, perioperative, and follow-up data are presented in this report.

Results

The surgical strategy varied between purely laparoscopic (n = 1), laparoscopically assisted (hybrid n = 3), or open techniques (n = 3) using original or suture-reconstructed mesh devices. The funnel mesh implantations in IPOM technique were combined with attached flat meshes in the appropriate position of the abdominal wall. No procedure-related complications occurred. The mean length of hospital stay was 12 days and the mean operating time was 171 min. No recurrence of PSH or incisional hernias was observed during a mean follow-up period of 12.3 months (range from 7 to 22).

Conclusion

The use of a 3-D mesh implant has so far shown to be a promising option in the treatment of primary and recurrent PSHs. Its use proved to be reasonable in both laparoscopic and open IPOM technique. PSHs were preferably repaired using the original, unmodified implant, but when we also found it safe to incise, place and then suture the mesh around the pre-existing ostomy.     

Mycotic aneurysm of the left ventricle: echocardiographic diagnosis.

We report an unusual case of myocardial mycotic aneurysm of the left ventricle resulting from a healed myocardial abscess caused by an aortic regurgitant jet lesion. The diagnosis was made during intraoperative transesophageal echocardiography and confirmed by surgical inspection. The echocardiographic features are described.     

Shape matters in protein mobility within membranes

The lateral mobility of proteins within cell membranes is usually thought to be dependent on their size and modulated by local heterogeneities of the membrane. Experiments using single-particle tracking on reconstituted membranes demonstrate that protein diffusion is significantly influenced by the interplay of membrane curvature, membrane tension, and protein shape. We find that the curvature-coupled voltage-gated potassium channel (KvAP) undergoes a significant increase in protein mobility under tension, whereas the mobility of the curvature-neutral water channel aquaporin 0 (AQP0) is insensitive to it. Such observations are well explained in terms of an effective friction coefficient of the protein induced by the local membrane deformation.Brownian motion plays an essential role in biological processes. Since the pioneering experiments of Perrin (1), the observation of diffusing objects has emerged as a mean to extract the rheological properties of the surrounding medium or the probe particle size. The theoretical investigation of diffusion of proteins within membranes has been studied widely going back to P. G. Saffman and M. Delbrück (SD). They investigated the hydrodynamic drag acting on a membrane inclusion when the membrane is described as a 2D fluid sheet of viscosity embedded within a less viscous fluid of viscosity η (2). In this theory, the diffusion coefficient D₀ in the limit of a large viscosity contrast between the membrane and bulk fluid is given by:The length is the length scale over which flow is generated within the bilayer by the inclusion, k_BT is the thermal energy, and γ is Euler’s constant. This model predicts a logarithmic dependence of D₀ on the protein radius a_p, which has been confirmed for some in vitro experiments on membranes containing transmembrane proteins (see ref. 3 and references therein). In contrast, the experiments of Gambin et al. (4) showed significant deviations from the SD theory.A possible origin for the discrepancy observed by Gambin et al. (4) is the significant local membrane deformation due to the interaction between the inclusion and the lipid bilayer (5). Naji et al. suggested in ref. 6 that inclusions experience additional dissipation, either due to internal flows within the membrane or to additional fluid flows produced by the deformed membrane. This work triggered a number of theoretical studies investigating the coupling of inclusion proteins with the membrane that had been pioneered by the Seifert’s group (see ref. 7 and references therein). Such studies have systematically gone beyond the SD model by including additional effects (8–12). So far, a thorough verification of these ideas has not been attempted. To investigate the effect of the protein–lipid coupling on the protein mobility, we study its dependence on membrane tension, because this parameter affects the local membrane deformation.In this work, we compare the mobility of two transmembrane proteins with the same lateral size, aquaporin 0 (AQP0) and a voltage-gated potassium channel (KvAP), reconstituted in giant unilamellar vesicles (GUVs). Whereas AQP0 does not deform locally the bilayer, KvAP locally bends the membrane (13). Using single-particle tracking (SPT), we demonstrate that the curvature-coupled protein KvAP undergoes a significant increase in mobility under tension, whereas the mobility of the curvature-neutral water channel AQP0 is insensitive to it. This difference, which goes beyond the SD model, is explained by an approach that includes the interplay between membrane deformation and friction with the surrounding medium and within the bilayer. This is compelling evidence that the Brownian motion of a shaping-membrane protein is not simply dependent on the inclusion size but also related to the lateral extension of the deformed membrane patch, which depends on tension.