True benefit or selection bias: an analysis of laparoscopic versus open splenectomy from the ACS-NSQIP

Background

By virtue of the benefits associated with minimally invasive approaches, laparoscopic splenectomy (LS) is believed to have better patient-related outcomes compared to open splenectomy (OS). However, there are limited data directly comparing the two techniques.

Methods

Patients who underwent elective LS and OS between 2005 and 2010 were identified from the public use file of the ACS-NSQIP database using the Current Procedural Terminology codes 38120 and 38100. Patients who had concomitant procedures were excluded. Because of the nonrandom assignment of surgical techniques, a selection bias could have been responsible for the differences in patient outcomes. Therefore, patient characteristics and comorbidities that were available and could have been potential confounders were compared and regression analysis was performed to determine independent risk factors associated with serious and overall morbidity as well as mortality.

Results

During the study period 1,644 and 851 patients underwent LS and OS, respectively. Compared to patients who underwent LS, patients who had OS had a longer median length of hospital stay (3 vs. 6 days, P < 0.0001) and higher incidences of serious (7 vs. 17 %, P < 0.0001) and overall morbidity (12 vs. 25 %, P < 0.0001) and mortality (1.4 vs. 3.3 %, P = 0.02). However, there were certain significant differences in the characteristics and comorbidities of the patients that could have confounded outcomes. On regression analysis, OS was not associated with higher mortality (OR = 1.43, 95 % CI 0.7–2.7, P = 0.28) but was associated with higher serious morbidity (OR = 1.8, 95 % CI 1.4–2.3, P = 0.001) and overall morbidity (OR = 2.0, 95 % CI 1.6–2.4, P = 0.0001).

Conclusion

After adjusting for available confounders, patients who underwent LS had lower morbidity and similar mortality rates. Although certain confounders such as previous surgical history, underlying pathology, and spleen size could still have potentially influenced outcomes, the data suggest that patient outcomes after LS are excellent and when technically possible a minimally invasive technique should be the preferred approach for splenectomy.     

Power-Dependent Investigation of Photo-Response from GeSn-Based p-i-n Photodetector Operating at High Power Density

We report an investigation on the photo-response from a GeSn-based photodetector using a tunable laser with a range of incident light power. An exponential increase in photocurrent and an exponential decay of responsivity with increase in incident optical power intensity were observed at higher optical power range. Time-resolved measurement provided evidence that indicated monomolecular and bimolecular recombination mechanisms for the photo-generated carriers for different incident optical power intensities. This investigation establishes the appropriate range of optical power intensity for GeSn-based photodetector operation.     

Left ventricular rotational deformation changes by speckle tracking imaging before and 24 hours after transcatheter closure of large secundum atrial septal defects in children

Background: Large atrial septal defects (ASDs) in children cause increased volume overload of the right side of the heart which in turn lead to impairment of left ventricular (LV) performance. Aim: The aim of this study was to evaluate immediate LV rotational deformation changes in children with large ASDs post-device closure and removal of right ventricle (RV) volume overload. Patients and Methods: Twenty children who underwent transcatheter closure (TCC) of large secundum ASDs were included in the study. LV rotational deformation was assessed pre- and 24 hours post-device closure using speckle tracking imaging (STI). Results: 55% were females with mean age 6.1 ± 3.5 years. LV peak basal clockwise rotation improved significantly (−6.9 ± 2.6° before vs −10.3 ± 4.1° after TCC, P = .005), and time to peak clockwise rotation (345.1 ± 124.7 milliseconds (ms) before vs 282.2 ± 82.9 ms after closure, P = .02). There was no significant difference in apical rotational parameters including peak counterclockwise rotation (P > .05 for both). LV twist (11.3 ± 3.8° before vs 17.5 ± 7.1° after closure, P = .001) and torsion (2.1 ± 0.7°/cm before vs 3.1 ± 1.2°/cm after closure, P = .01) were significantly improved, mainly as the result of improvement of LV basal rotation. LV revealed a significant increase in LV end-diastolic volumes (P = .02) 24 hour after TCC with no significant change (P > .05) in end-systolic volumes after closure. Conclusion: Increased peak LV twisting and torsion were attributed to the improved peak systolic clockwise basal rotation after TCC of large ASDs in children.     

Gap phenomenon in the bundle of his conduction]

His bundle electrograms recorded during atrial stimulation with the extrastimulus technique permitted the analysis of the so called gaps in bundle branch conduction. Three different types of gaps were identified each with a distinct electrophysiological mechanism. In type I gap a CLBBB pattern disappeared at shorter coupling (A1-A2) intervals because the more premature impulses encountered a greater degree of the delay at the A-V node therefore reaching the left bundle branch after its effective refractory period had ended. During this part of the cycle the H1-H2 were longer and H2-V2 intervals shorter than when CRBBB was present. In type II gap a CRBBB pattern disappeared at shorter coupling intervals because the premature impulses met a greater delay in the proximal portions of the His-Purkinje system. In consequence, they arrived at the right bundle branch when its effective refractory period had expired. When this occurred the H1-H2 interval were shorter and the H2-V2 longer than those at which CRBBB had been present. The patient with type III gap had CLBBB. A-V conduction was possible through the right bundle branch very late in the cycle. However, it could not occur at shorter coupling intervals finally reappearing at even shorter coupling intervals. True supernormal conduction or vagal pulsatile discharges could have been present. Yet, we favor, as the most likely possibility, the existence of 2:1 phase 4 block with latent or abortive escapes not recorded in the surface leads.     

Secondary neoplasms of the esophagus

A review of 62 cases of esophageal involvement by secondary neoplasms is reported. The common routes of esophageal involvement are by direct extension of the tumor from the contiguous or adjacent organs (45.2%), via mediastinal nodes (35.5%), and hematogenous spread from a distant primary (19.3%). In the first 2 modes of esophageal involvement, the diagnosis is usually obvious but hematogenous metastases to the esophagus usually pose a diagnostic challenge. Radiologically, hematogenous metastases show a spectrum of features consisting of a short segment of progressive stricture with normal to minimally irregular mucosa, a submucosal mass with or without ulceration, a polypoid mass or masses, and defects in esophageal motility including secondary achalasia. Since endoscopy and biopsy have limited diagnostic yield, radiologic diagnosis plays a key role in the diagnosis of secondary neoplasms of the esophagus irrespective of their mode of spread to the esophagus.     

Rotator Cuff Fibro-Adipogenic Progenitors Demonstrate Highest Concentration,Proliferative Capacity,and Adipogenic Potential Across Muscle Groups

Fatty infiltration (FI) of rotator cuff (RC) muscles is common in patients with RC tears. Studies have demonstrated that fibro-adipogenic progenitors (FAPs), a population of resident muscle stem cells, are the main contributors of FI, which adversely affects muscle quality and RC repair success. Although FI is common in RC injuries, it is not frequently reported after other musculotendinous injuries. Additionally, studies have shown the development of different pathology patterns across muscle groups suggestive of intrinsic differences in cellular composition and behavior. This study evaluates FAP distribution and differentiation properties across anatomic locations in mice. Muscles from seven different anatomic locations were harvested from PDGFRα-eGFP FAP reporter mice. FAPs were quantified using histology and FACS sorting with BD Aria II with CD31⁻/CD45⁻/Integrinα7⁻/Sca-1⁺ and PDGFRα reporter signal (n = 3 per muscle). The cells were analyzed for adipogenesis using immunocytochemistry and for proliferation properties with Brdu-Ki67 staining. In a separate group of mice, RC and tibialis anterior muscles received glycerol injection and were harvested after 2 weeks for FI quantification (n = 4). One-way analysis of variance was used for statistical comparisons among groups, with significance at p < 0.05. FAPs from the RC, masseter, and paraspinal muscles were more numerous and demonstrated greater proliferative capacity and adipogenic potency than those from the tibialis anterior and gastrocnemius. The RC demonstrated significantly greater levels of FI than the tibialis anterior after glycerol-injection injury. Clinical Significance: This study suggests differences in FAP distribution and differentiation characteristics may account for the propensity to develop FI in RC tears as compared with other musculotendinous injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1113-1121, 2020     

The esophagus after endoscopic pneumatic balloon dilatation for achalasia

The changes seen on contrast esophagrams after endoscopic pneumatic balloon dilation for the treatment of achalasia are described and illustrated. Sixteen patients had esophagrams within 24 hr after dilation and follow-up esophagrams were obtained 6-24 months later. The radiographic features evaluated in the early postdilation period included detection of esophageal perforation, diameter of the esophagogastric channel, proximal esophageal dilatation, mucosal integrity, and emptying dynamics of the esophagus. Fourteen patients (88%) had immediate symptomatic improvement of dysphagia. The mean increase in diameter of the esophagogastric channel was 6.5 mm (range, 4.8-9 mm) relative to a pretreatment esophagram. Emptying dynamics of the esophagus improved significantly in 12 patients (75%). One patient developed esophageal perforation requiring surgery. On the follow-up esophagrams obtained 6-24 months later, the evaluation was for sustained dilatation of esophagogastric channel, decrease in esophageal dilatation, and improved emptying dynamics of the esophagus. The effective esophagogastric channel diameter of 8-10 mm correlated well with improved clinical response in 88% of the patients.