Cross cultural comparison of constipation profiles at tertiary care centers between India and USA.

BACKGROUND: Despite potential differences in patient perception of chronic constipation (CC) in geographically and culturally distinct regions, head-to-head studies comparing the clinical profile, constipation severity, impact on quality of life (QOL) and economic impact are lacking. METHODS: We conducted a cross-sectional cohort study of patients presenting with CC to tertiary care centers in the USA and India. Standardized instruments were used to assess constipation subtype, disease severity, disease-specific QOL, somatization, and psychiatric comorbidities. We used multivariable linear regression to determine the predictors of QOL and number of healthcare visits. KEY RESULTS: Sixty-six and 98 patients with CC were enrolled in the USA and India, respectively. Indian patients with CC had significantly more frequent bowel movements/week compared to their USA counterparts (Median 5 vs 3, P < .0001). The proportion of patients with Bristol stool form scale type 1 and 2 was significantly higher in the USA compared to India (65.5% vs 48%, P = .04). Higher depression score (P = .001), more severe constipation symptoms (P = .001) and site of the study being USA (P = .008) independently predicted worse QOL. Indian patients (P < .001) and worse QOL (P = .02) were independent predictors of number of healthcare visits in the last 12 months. CONCLUSIONS AND INFERENCES: Indian patients with CC have more frequent and softer bowel movements compared to those in the USA suggesting significant differences in perception of CC in different geographic and cultural settings. QOL and economic impact related to constipation varies with geographic/cultural setting irrespective of other clinical and psychosomatic features.

Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography.

Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach.

Small bowel fed response as measured by wireless motility capsule: Comparative analysis in healthy, gastroparetic, and constipated subjects.

BACKGROUND: Small bowel fed response is an increased contractile activity pattern following the ingestion of a meal. Postprandial motility is traditionally evaluated using small bowel manometry. Wireless motility capsule (WMC) is an ingestible wireless capsule that measures pH, temperature, and intraluminal pressure. The primary aim of the study was to assess small bowel fed response captured with the non-invasive WMC. The secondary aim was to compare the fed response patterns between healthy subjects and patients with motility disorders of gastroparesis and constipation. METHODS: All subjects had 250 cc Ensure® meal 6 hours after WMC ingestion. Frequency of contractions (Ct), area under the curve (AUC), and motility index (MI) were analyzed during 30 minutes of pre-prandial baseline and 60 minutes postprandially in 20-minute windows. KEY RESULTS: One hundred and eighty-eight subjects (107 healthy, 23 gastroparetics, 58 constipated) were analyzed. Healthy: Ct, AUC, and MI all increased significantly immediately after meal ingestion (P < .01). Motility parameters peak at 20-40 minutes postmeal. The motor activity decreased at the end of postprandial hour, but was still significantly higher than the fasting baseline (P < .01). Gastroparetics: All motility parameters failed to increase significantly compared to the baseline throughout the entire postprandial hour. Constipated: The fed response was similar to healthy subjects. CONCLUSIONS AND INFERENCES: The small bowel fed response was readily observed in healthy and chronic constipation subjects with WMC but is blunted in gastroparetics. A blunted small bowel fed response suggests neuropathic changes outside the stomach and may contribute to postprandial symptoms.

Number of retained radiopaque markers on a colonic transit study does not correlate with symptom severity or quality of life in chronic constipation.

BACKGROUND: Ingestion of radiopaque markers (ROM) is frequently used to determine colonic transit in chronic constipation. Although ≥20% of retained markers at 5 days defines slow-transit constipation, some clinicians use the number of retained markers to determine disease severity. METHODS: We assembled a cross-sectional cohort of patients presenting for evaluation of chronic constipation who underwent transit testing by ROM and completed validated symptom severity and quality-of-life (QOL) measures. We performed a correlation analysis to determine whether there was an association between number of retained markers and symptom severity and QOL. KEY RESULTS: Among 159 patients undergoing evaluation for chronic constipation, there was poor correlation between the number of retained markers and symptom severity (R = .09, P = .25) and QOL. Among the 55 patients with slow-transit constipation defined by ≥5 retained markers retained on day 5, there were similarly poor correlations between symptom severity (R = .17, P = .21) and QOL (R = .07, P = .60). Excluding patients with irritable bowel syndrome and outlet obstruction by balloon expulsion testing did not materially alter our results, nor did a multivariable analysis controlling for demographic and psychiatric confounders. CONCLUSIONS AND INFERENCES: Among patients with chronic constipation, number of retained markers on a ROM colonic transit study does not correlate with measures of symptom severity or QOL. Clinicians should be cautious about overinterpreting ROM transit testing.

Inflammatory Effects of Menthol vs. Non-menthol Cigarette Smoke Extract on Human Lung Epithelial Cells: A Double-Hit on TRPM8 by Reactive Oxygen Species and Menthol.

Clinical studies suggest that smokers with chronic obstructive pulmonary disease who use menthol cigarettes may display more severe lung inflammation than those who smoke non-menthol cigarette. However, the mechanisms for this difference remain unclear. Menthol is a ligand of transient receptor potential melastatin-8 (TRPM8), a Ca2+-permeant channel sensitive to reactive oxygen species (ROS). We previously reported that exposure of human bronchial epithelial cells (HBECs) to non-menthol cigarette smoke extract (Non-M-CSE) triggers a cascade of inflammatory signaling leading to IL-8 induction. In this study, we used this in vitro model to compare the inflammatory effects of menthol cigarette smoke extract (M-CSE) and Non-M-CSE and delineate the mechanisms underlying the differences in their impacts. Compared with Non-M-CSE, M-CSE initially increased a similar level of extracellular ROS, suggesting the equivalent oxidant potency. However, M-CSE subsequently produced more remarkable elevations in intracellular Ca2+, activation of the mitogen-activated protein kinases (MAPKs)/nuclear factor-κB (NF-κB) signaling, and IL-8 induction. The extracellular ROS responses to both CSE types were totally inhibited by N-acetyl-cysteine (NAC; a ROS scavenger). The intracellular Ca2+ responses to both CSE types were also totally prevented by NAC, AMTB (a TRPM8 antagonist), or EGTA (an extracellular Ca2+ chelator). The activation of the MAPK/NF-κB signaling and induction of IL-8 to both CSE types were suppressed to similar levels by NAC, AMTB, or EGTA. These results suggest that, in addition to ROS generated by both CSE types, the menthol in M-CSE may act as another stimulus to further activate TRPM8 and induce the observed responses. We also found that menthol combined with Non-M-CSE induced greater responses of intracellular Ca2+ and IL-8 compared with Non-M-CSE alone. Moreover, we confirmed the essential role of TRPM8 in these responses to Non-M-CSE or M-CSE and the difference in these responses between the both CSE types using HBECs with TRPM8 knockdown and TRPM8 knockout, and using HEK293 cells transfected with hTRPM8. Thus, compared with exposure to Non-M-CSE, exposure to M-CSE induced greater TRPM8-mediated inflammatory responses in HBECs. These augmented effects may be due to a double-hit on lung epithelial TRPM8 by ROS generated from CSE and the menthol in M-CSE.

Cyclic Vomiting Syndrome is characterized by altered functional brain connectivity of the insular cortex: A cross-comparison with migraine and healthy adults.

Cyclic Vomiting Syndrome (CVS) has been linked to episodic migraine, yet little is known about the precise brain-based mechanisms underpinning CVS, and whether these associated conditions share similar pathophysiology. We investigated the functional integrity of salience (SLN) and sensorimotor (SMN) intrinsic connectivity networks in CVS, migraine and healthy controls using brain functional Magnetic Resonance Imaging. CVS, relative to both migraine and controls, showed increased SLN connectivity to middle/posterior insula, a key brain region for nausea and viscerosensory processing. In contrast, this same region showed diminished SMN connectivity in both CVS and migraine. These results highlight both unique and potentially shared pathophysiology between these conditions, and suggest a potential target for therapeutics in future studies.

Gender differences in chronic constipation on anorectal motility.

BACKGROUND: The epidemiology of chronic constipation (CC) skews toward female predominance, yet men make up an important component of those suffering from CC. We sought to determine whether there are sex-specific differences in symptoms and physiologic parameters on anorectal manometry (ARM). METHODS: We performed a case-control analysis of sequential men and age-matched women (2:1 ratio) presenting for ARM as part of the evaluation of CC. We collected physiologic parameters derived from 3D high-resolution ARM in addition to the ROME III constipation module and the Pelvic Floor Distress Inventory 20 (PFDI-20) questionnaires. We analyzed univariate, sex-specific differences in ARM physiologic parameters and PFDI-20 parameters and adjusted for putative confounders using multivariate logistic regression. KEY RESULTS: Our study enrolled 80 men and 165 age-matched women. Men had a higher median sphincter resting pressure (81.2 vs 75.2 mm Hg, P=.01) and mean squeeze pressure (257.0 vs 170.5 mm Hg, P<.0001) than women. Although men reported significantly less severe straining and incomplete evacuation, they had greater mean rectoanal pressure differential (-106.7 vs -71.1 mm Hg, P<.0001), smaller mean defecation index (0.17 vs 0.27, P=.03) and higher volume threshold for urgency (115.2 v. 103.4 mL, P=.03). However, women were more likely to have abnormal balloon expulsion time (BET) than men (52.7% vs 35.0%, P=.01). After multivariate analysis, male gender was the only independent predictor of a normal BET (OR: 0.48, 95% CI: 0.27-0.86, P=.01). CONCLUSIONS & INFERENCES: Men and women with CC differ with regard to symptom severity and physiologic parameters derived from ARM suggesting differences in their pathophysiology.

Prolonged length of stay associated with air leak following pulmonary resection has a negative impact on hospital margin.

BACKGROUND: Protracted hospitalizations due to air leaks following lung resections are a significant source of morbidity and prolonged hospital length of stay (LOS), with potentially significant impact on hospital margins. This study aimed to evaluate the relationship between air leaks, LOS, and financial outcomes among discharges following lung resections. MATERIALS AND METHODS: The Medicare Provider Analysis and Review file for fiscal year 2012 was utilized to identify inpatient hospital discharges that recorded International Classification of Diseases (ICD-9) procedure codes for lobectomy, segmentectomy, and lung volume reduction surgery (n=21,717). Discharges coded with postoperative air leaks (ICD-9-CM codes 512.2 and 512.84) were defined as the air leak diagnosis group (n=2,947), then subcategorized by LOS: 1) <7 days; 2) 7-10 days; and 3) ≥11 days. Median hospital charges, costs, payments, and payment-to-cost ratios were compared between non-air leak and air leak groups, and across LOS subcategories. RESULTS: For identified patients, hospital charges, costs, and payments were significantly greater among patients with air leak diagnoses compared to patients without (P<0.001). Hospital charges and costs increased substantially with prolonged LOS, but were not matched by a proportionate increase in hospital payments. Patients with LOS <7, 7-10, and ≥11 days had median hospital charges of US $57,129, $73,572, and $115,623, and costs of $17,594, $21,711, and $33,786, respectively. Hospital payment increases were substantially lower at $16,494, $16,307, and $19,337, respectively. The payment-to-cost ratio significantly lowered with each LOS increase (P<0.001). Higher inpatient hospital mortality was observed among the LOS ≥11 days subgroup compared with the LOS <11 days subgroup (P<0.001). CONCLUSION: Patients who develop prolonged air leaks after lobectomy, segmentectomy, or lung volume reduction surgery have the best clinical and financial outcomes. Hospitals experience markedly lower payment-to-cost ratios as LOS increases. Interventions minimizing air leak or allowing outpatient management will improve financial performance and hospital margins for lung surgery.

STEM tomography reveals that the canalicular system and α-granules remain separate compartments during early secretion stages in blood platelets.

UNLABELLED: ESSENTIALS: How platelets organize their α-granule cargo and use their canalicular system remains controversial. Past structural studies were limited due to small sampling volumes or decreased resolution. Our analyses revealed homogeneous granules and a closed canalicular system that opened on activation. Understanding how platelets alter their membranes during activation and secretion elucidates hemostasis. BACKGROUND: Platelets survey the vasculature for damage and, in response, activate and release a wide range of proteins from their α-granules. Alpha-granules may be biochemically and structurally heterogeneous; however, other studies suggest that they may be more homogeneous with the observed variation reflecting granule dynamics rather than fundamental differences. OBJECTIVES: Our aim was to address how the structural organization of α-granules supports their dynamics. METHODS: To preserve the native state, we prepared platelets by high-pressure freezing and freeze-substitution; and to image nearly entire cells, we recorded tomographic data in the scanning transmission electron microscope (STEM). RESULTS AND CONCLUSIONS: In resting platelets, we observed a morphologically homogeneous α-granule population that displayed little variation in overall matrix electron density in freeze-substituted preparations (i.e., macro-homogeneity). In resting platelets, the incidence of tubular granule extensions was low, ~4%, but this increased by > 10-fold during early steps in platelet secretion. Using STEM, we observed that the initially decondensing α-granules and the canalicular system remained as separate membrane domains. Decondensing α-granules were found to fuse heterotypically with the plasma membrane via long, tubular connections or homotypically with each other. The frequency of canalicular system fusion with the plasma membrane also increased by about three-fold. Our results validate the utility of freeze-substitution and STEM tomography for characterizing platelet granule secretion and suggest a model in which fusion of platelet α-granules with the plasma membrane occurs via long tubular connections that may provide a spatially limited access route for the timed release of α-granule proteins.

Subnoise detection of a fast random event.

Observation of random, nonrepetitive phenomena is of critical importance in astronomy, spectroscopy, biology, and remote sensing. Heralded by weak signals, hidden in noise, they pose basic detection challenges. In contrast to repetitive waveforms, a single-instance signal cannot be separated from noise through averaging. Here, we show that a fast, randomly occurring event can be detected and extracted from a noisy background without conventional averaging. An isolated 80-picosecond pulse was received with confidence level exceeding 99%, even when accompanied by noise. Our detector relies on instantaneous spectral cloning and a single-step, coherent field processor. The ability to extract fast, subnoise events is expected to increase detection sensitivity in multiple disciplines. Additionally, the new spectral-cloning receiver can potentially intercept communication signals that are presently considered secure.

Two-fold transmission reach enhancement enabled by transmitter-side digital backpropagation and optical frequency comb-derived information carriers.

We demonstrate a two-fold reach extension of 16 GBaud 16-Quadrature Amplitude Modulation (QAM) wavelength division multiplexed (WDM) system based on erbium doped fiber amplifier (EDFA)-only amplified standard and single mode fiber -based link. The result is enabled by transmitter-side digital backpropagation and frequency referenced carriers drawn from a parametric comb.

GEOPHYSICS. Layered deformation in the Taiwan orogen.

The underthrusting of continental crust during mountain building is an issue of debate for orogens at convergent continental margins. We report three-dimensional seismic anisotropic tomography of Taiwan that shows a nearly 90° rotation of anisotropic fabrics across a 10- to 20-kilometer depth, consistent with the presence of two layers of deformation. The upper crust is dominated by collision-related compressional deformation, whereas the lower crust of Taiwan, mostly the crust of the subducted Eurasian plate, is dominated by convergence-parallel shear deformation. We interpret this lower crustal shearing as driven by the continuous sinking of the Eurasian mantle lithosphere when the surface of the subducted plate is coupled with the orogen. The two-layer deformation clearly defines the role of subduction in the formation of the Taiwan mountain belt.

Regional gastrointestinal transit and pH studied in 215 healthy volunteers using the wireless motility capsule: influence of age, gender, study country and testing protocol.

BACKGROUND: The wireless motility capsule (WMC) offers the ability to investigate luminal gastrointestinal (GI) physiology in a minimally invasive manner. AIM: To investigate the effect of testing protocol, gender, age and study country on regional GI transit times and associated pH values using the WMC. METHODS: Regional GI transit times and pH values were determined in 215 healthy volunteers from USA and Sweden studied using the WMC over a 6.5-year period. The effects of test protocol, gender, age and study country were examined. RESULTS: For GI transit times, testing protocol was associated with differences in gastric emptying time (GET; shorter with protocol 2 (motility capsule ingested immediately after meal) vs. protocol 1 (motility capsule immediately before): median difference: 52 min, P = 0.0063) and colonic transit time (CTT; longer with protocol 2: median 140 min, P = 0.0189), but had no overall effect on whole gut transit time. Females had longer GET (by median 17 min, P = 0.0307), and also longer CTT by (104 min, P = 0.0285) and whole gut transit time by (263 min, P = 0.0077). Increasing age was associated with shorter small bowel transit time (P = 0.002), and study country also influenced small bowel and CTTs. Whole gut and CTTs showed clustering of data at values separated by 24 h, suggesting that describing these measures as continuous variables is invalid. Testing protocol, gender and study country also significantly influenced pH values. CONCLUSIONS: Regional GI transit times and pH values, delineated using the wireless motility capsule (WMC), vary based on testing protocol, gender, age and country. Standardisation of testing is crucial for cross-referencing in clinical practice and future research.

Resting anal pressure, not outlet obstruction or transit, predicts healthcare utilization in chronic constipation: a retrospective cohort analysis.

BACKGROUND: Chronic constipation is common and exerts a considerable burden on health-related quality of life and healthcare resource utilization. Anorectal manometry (ARM) and colonic transit testing have allowed classification of subtypes of constipation, raising promise of targeted treatments. There has been limited study of the correlation between physiological parameters and healthcare utilization. METHODS: All patients undergoing ARM and colonic transit testing for chronic constipation at two tertiary care centers from 2000 to 2014 were included in this retrospective study. Our primary outcomes included number of constipation-related and gastroenterology visits per year. Multivariate linear regression adjusting for confounders defined independent effect of measures of colonic and anorectal function on healthcare utilization. KEY RESULTS: Our study included 612 patients with chronic constipation. More than 50% (n = 333) of patients had outlet obstruction by means of balloon expulsion testing and 43.5% (n = 266) had slow colonic transit. On unadjusted analysis, outlet obstruction (1.98 vs 1.68), slow transit (2.40 vs 2.07) and high resting anal pressure (2.16 vs 1.76) were all associated with greater constipation-related visits/year compared to patients without each of those parameters (p < 0.05 for all). Outlet obstruction and high resting anal pressure were also associated with greater number of gastroenterology visits/year. After multivariate adjustment, high resting anal pressure was the only independent predictor of increased constipation-related visits/year (p = 0.02) and gastroenterology visits/year (p = 0.04). CONCLUSIONS & INFERENCES: Among patients with chronic constipation, high resting anal pressure, rather than outlet obstruction or slow transit, predicts healthcare resource utilization.

APPLIED OPTICS. Overcoming Kerr-induced capacity limit in optical fiber transmission.

Nonlinear optical response of silica imposes a fundamental limit on the information transfer capacity in optical fibers. Communication beyond this limit requires higher signal power and suppression of nonlinear distortions to prevent irreversible information loss. The nonlinear interaction in silica is a deterministic phenomenon that can, in principle, be completely reversed. However, attempts to remove the effects of nonlinear propagation have led to only modest improvements, and the precise physical mechanism preventing nonlinear cancellation remains unknown. We demonstrate that optical carrier stability plays a critical role in canceling Kerr-induced distortions and that nonlinear wave interaction in silica can be substantially reverted if optical carriers possess a sufficient degree of mutual coherence. These measurements indicate that fiber information capacity can be notably increased over previous estimates.

Duodenal rather than antral motility contractile parameters correlate with symptom severity in gastroparesis patients.

BACKGROUND: Studies of symptomatic gastroparetics consistently find poor correlation with gastric emptying. We hypothesized that concomitant small bowel dysmotility may play a role in symptom causation in gastroparesis and sought to test this hypothesis by using wireless motility capsule (WMC) testing to simultaneously measure antral and duodenal area under pressure curve (AUC) in patients with delayed gastric emptying. METHODS: Using a cohort from a multicenter clinical trial and a separate tertiary clinical database, we identified gastroparetics that underwent concurrent WMC testing and completed the Gastroparesis Cardinal Symptom Index, a validated questionnaire. Our study included 35 gastroparetics defined by a gastric emptying time (GET) ≥ 5 h. Antral and duodenal AUC were assessed at 1-h windows pre-GET and post-GET, respectively. KEY RESULTS: We found moderate correlations between duodenal AUC and symptom severity in the combined cohort (n = 35; R = -0.42; p = 0.01; 95% CI -0.7, -0.1). Removing patients with colonic delay resulted in a stronger correlation of duodenal AUC to symptom severity (n = 21; R = -0.63; p < 0.01; 95% CI -0.81, -0.31). The multicenter trial (n = 20) and clinical practice cohorts (n = 15) had significantly different symptom severity and exclusion criteria. When analyzed separately, significant correlations between duodenal AUC and symptom severity were observed (R = -0.71; p < 0.01; 95% CI -0.9, -0.4 and R = -0.72; p < 0.01; 95% CI -0.9, -0.3, respectively). Symptom severity and antral motility showed no correlation. CONCLUSIONS & INFERENCES: We found significant correlations between duodenal AUC and symptom severity in two cohorts of gastroparetics. Small bowel motility may contribute to symptom generation in gastroparetic patients and this may inform therapeutic considerations.

New thinking on clinical utility: hard lessons for molecular diagnostics.

OBJECTIVES: To describe 5 basic requirements for planning, implementing, and proving clinical utility for diagnostic tests, drawing on recent reimbursement decisions. STUDY DESIGN: Review of recent reimbursement decisions by Palmetto GBA's MolDx program, and summary of lessons learned. METHODS: Qualitative review of publicly available coverage and reimbursement decisions, plus our industry experience. RESULTS: Lack of clinical utility data is the most commonly cited reason for why companies fail to receive favorable coverage and reimbursement decisions in this rapidly growing industry. We summarize 5 strategies to establish clinical utility and secure coverage with reimbursement: 1) understanding that outcomes are hard to capture, but that clinical behavior change is always proximate to outcomes change, 2) starting clinical utility studies early, 3) learning from successes and failures, 4) determining clinical utility with rigorous science, and 5) understanding that clinical utility studies may need to involve private payers and providers from the start. CONCLUSIONS: Coverage and reimbursement are shifting from relatively low entry barriers to higher, evidence-based barriers that will require test developers to generate evidence of the net clinical benefits before widespread clinical use will occur. Concerted, early investment in rigorously designed clinical utility studies is necessary.

High-speed, rate-scalable photonic-assisted digitizer equalization by frequency comb referencing.

A scalable analog-to-digital converter based on polychromatic sampling and optical-domain frequency referencing is described. The new architecture relies on low-distortion replication of an optical signal to spectrally distinct copies and subsequent polychromatic parametric sampling. Frequency comb referencing of parametric replication and sampling was used to convert processor distortions into quasi-stationary impairments and enable a practical equalization implementation. The operation of the new digitizer was demonstrated at 30 GS/s, achieving 6.5 effective number of bits in the first Nyquist zone. In contrast to conventional analog-to-digital converters, the new preprocessor sampling bandwidth is not restricted to the first Nyquist zone, and can operate in the second and third Nyquist zones beyond 40 GHz.

Ultrafast optics. Ultrafast optical control by few photons in engineered fiber.

Fast control of a strong optical beam by a few photons is an outstanding challenge that limits the performance of quantum sensors and optical processing devices. We report that a fast and efficient optical gate can be realized in an optical fiber that has been engineered with molecular-scale accuracy. Highly efficient, distributed phase-matched photon-photon interaction was achieved in the fiber with locally controlled, nanometer-scale core variations. A three-photon input was used to manipulate a Watt-scale beam at a speed exceeding 500 gigahertz. In addition to very fast beam control, the results provide a path to developing a new class of sensitive receivers capable of operating at very high rates.

Transition to a novel advanced integrated vitrectomy platform: comparison of the surgical impact of moving from the Accurus vitrectomy platform to the Constellation Vision System for microincisional vitrectomy surgery.

BACKGROUND: Microincisional vitrectomy surgery (MIVS) is the current standard surgical approach for pars plana vitrectomy. Historically, the most common surgical platform for vitrectomy surgery, since its introduction in 1997, has been the Accurus vitrectomy system. Recent introduction of the next generation of vitrectomy platforms has generated concerns associated with transitioning to new technology in the operating room environment. This study compared, in a matched fashion, surgical use of the Accurus vitrectomy system and the next generation Constellation Vision System to evaluate surgical efficiencies, complications, and user perceptions of this transition. METHODS: Electronic health records were abstracted as a hospital quality assurance activity and included all vitreoretinal surgical procedures at the Bascom Palmer Eye Institute, Anne Bates Leach Eye Hospital, during two discrete 12-month time periods. These two periods reflected dedicated usage of the Accurus (June 2008-May 2009) and Constellation Vision (July 2009-June 2010) systems. Data were limited to a single surgeon and evaluated for operating room (OR) total time usage/day, OR case time/case, and OR surgical time/case. Further analysis evaluated all patients undergoing combined MIVS and clear cornea phacoemulsification/intraocular lens (IOL) implantation during each individual time period to determine the impact of the instrumentation on these parameters. All records were evaluated for intraoperative complications. RESULTS: Five hundred and fourteen eligible patients underwent MIVS during the 2-year study windows, with 281 patients undergoing surgery with the Accurus system and 233 patients undergoing surgery with the Constellation system. Combined MIVS and phacoemulsification with IOL implantation was performed 141 times during this period with the Accurus and 158 times during the second study period with the Constellation. Total number of patients operated per day increased from 7.55 with Accurus to 8.53 with Constellation. Surgical room time decreased from 56 minutes with Accurus to 52 minutes with Constellation, and procedure time decreased from 35 minutes with Accurus to 31 minutes with Constellation (P < 0.004). Combined MIVS/phacoemulsification surgery saw similar declines in surgical room time and procedure time (P < 0.001). Subset analysis of procedures limited by case number per day (eg, four cases/day, five cases/day, six cases/day, and seven or more cases/day) showed similar outcomes with a decrease in surgical room time and procedure time. No increases in surgery-related complications were noted by quality assurance review during these time periods. DISCUSSION: Transitioning to advanced surgical technology is a complex issue for the surgeon, the hospital team, and the hospital administration. This study documents improvement in three significant measures of surgical efficiency: operative number of patients per day, operative room time, and surgical procedure time that reflect the positive impact of the novel, combined, integrated, posterior and anterior, ophthalmologic surgical platform of the Constellation Vision System. These data are imperative to evaluate the impact of transition from one surgical platform to another. During this transition, hospital quality assurance review and surgeon evaluation of operative complications showed no increased concerns for the shift from the Accurus to the Constellation Vision System surgical platform. Further, both operative staff and surgeons felt that the transition to the Constellation was not associated with increases in difficulty with setup, turnover, or use and that the Constellation decreased safety concerns for surgical usage. Ultimately, in this case, new technology benefited the surgeon, the patient, and the hospital.