Extracorporeal membrane oxygenation in infants with meconium aspiration syndrome: a decade of experience with venovenous ECMO

Background

Despite the emergence of new therapies for respiratory failure of the newborn with meconium aspiration syndrome (MAS), extracorporeal membrane oxygenation (ECMO) has a significant role as a rescue modality in these infants. Our objective was to compare the use of venovenous (VV) vs venoarterial (VA) ECMO in newborns with MAS who need ECMO and to ascertain the impact of new therapies in these infants during the last decade. We also evaluated how disease severity or time of ECMO initiation affected mortality and morbidity.

Methods

A report of 12 years experience (1990-2002) of a single center, comparing VV and VA ECMO, is given. Venovenous ECMO was the preferred rescue modality for respiratory failure unresponsive to maximal medical therapy. Venoarterial ECMO was used only when the placement of a VV ECMO 14-F catheter was not possible; 128 patients met ECMO criteria, 114 were treated with VV ECMO, and 12 with VA ECMO. Two patients were converted from VV to VA ECMO.

Results

Venovenous and VA ECMO patients had comparable birth weight (mean ± SEM, 3.48 ± 0.05 vs 3.35 ± 0.15 kg) and gestational age (40.3 ± 0.1 vs 40.7 ± 0.3 weeks). Before ECMO, there was no difference between VV and VA ECMO patients in oxygenation index (60 ± 3 vs 63 ± 8), mean airway pressure (19.5 ± 0.4 vs 20.8 ± 1.5 cm H₂O), alveolar-arterial O₂ gradient (630 ± 2 vs 632 ± 4 torr), ECMO cannulation age (median [25th-75th percentiles], 23 [14-47] vs 26 [14-123] hours), or in the % of patients who needed vasopressors/inotropes (98% vs 100%). From November 1994, inhaled nitric oxide (NO) was available. Before VV ECMO, 67% of the patients received NO, 24% received surfactant, and 48% were treated with high-frequency ventilation (HFV). There was no significant difference between VV and VA ECMO patients in survival rate (94% vs 92%), ECMO duration (88 [64-116] vs 94 [55-130] hours), time of extubation (9 [7-11] vs 14 [9-15] days), age at discharge (23 [18-30] vs 27 [15-41] days), or incidence of short-term intracranial complications (5.3% vs 16.7%). For the total cohort of 126 infants, indices of disease severity (oxygenation index, alveolar-arterial O₂ gradient, mean airway pressure) did not correlate with outcome measures. Delay in ECMO initiation (>96 hours) was associated with prolonged mechanical ventilation and hospitalization (P < .01). New therapies (NO, HFV, surfactant) in the second part of the decade were associated with a longer ECMO duration (98 [80-131] vs 87 [60-116] hours; P < .05), no delay in ECMO initiation time (23 [10-40] vs 24 [14-52] hours), and no significant change in survival (97% vs 92.5%). No patient was treated with VA ECMO after 1994.

Conclusions

Venovenous ECMO is as reliable as VA ECMO in newborns with MAS in severe respiratory failure who need ECMO. Delay in ECMO initiation may result in prolonged mechanical ventilation and increased length of hospital stay. The emergence of new conventional therapies (NO, HFV, surfactant) and particularly increased experience enable sole use of VV ECMO with no significant change in survival in infants with MAS.     

Tarlov Cyst and Infertility

Background/Objective:

Tarlov cysts or spinal perineurial cysts are uncommon lesions. These are mostly incidental findings on magnetic resonance imaging or myelograms. The objectives of this study were to describe Tarlov cysts of the sacral region as a potential cause for retrograde ejaculations and review available management options.

Methods:

Case report and literature review.

Results:

A 28-year-old man presented with back pain and retrograde ejaculations resulting in infertility. After microsurgical excision of large perineurial cysts, back pain resolved, but semen quality showed only marginal improvement. Later, the couple successfully conceived by intrauterine insemination. To the best of our knowledge, this is the first reported case of Tarlov cyst associated with retrograde ejaculation and infertility.

Conclusions:

Despite being mostly asymptomatic and an incidental finding, Tarlov cyst is an important clinical entity because of its tendency to increase in size with time. Tarlov cysts of the sacral and cauda equina region may be a rare underlying cause in otherwise unexplained retrograde ejaculations and infertility. Microsurgical excision may be a good option in a select group of patients.     

Clinical and radiological outcome of anterior–posterior fusion versus transforaminal lumbar interbody fusion for symptomatic disc degeneration: a retrospective comparative study of 133 patients

Abundant data are available for direct anterior/posterior spine fusion (APF) and some for transforaminal lumbar interbody fusion (TLIF), but only few studies from one institution compares the two techniques. One-hundred and thirty-three patients were retrospectively analyzed, 68 having APF and 65 having TLIF. All patients had symptomatic disc degeneration of the lumbar spine. Only those with one or two-level surgeries were included. Clinical chart and radiologic reviews were done, fusion solidity assessed, and functional outcomes determined by pre- and postoperative SF-36 and postoperative Oswestry Disability Index (ODI), and a satisfaction questionnaire. The minimum follow-up was 24 months. The mean operating room time and hospital length of stay were less in the TLIF group. The blood loss was slightly less in the TLIF group (409 vs. 480 cc.). Intra-operative complications were higher in the APF group, mostly due to vein lacerations in the anterior retroperitoneal approach. Postoperative complications were higher in the TLIF group due to graft material extruding against the nerve root or wound drainage. The pseudarthrosis rate was statistically equal (APF 17.6% and TLIF 23.1%) and was higher than most published reports. Significant improvements were noted in both groups for the SF-36 questionnaires. The mean ODI scores at follow-up were 33.5 for the APF and 39.5 for the TLIF group. The patient satisfaction rate was equal for the two groups. This work is dedicated to the memory of Grace and Julia Hanson.     

Biomechanical evaluation of a new AxiaLIF technique for two-level lumbar fusion

Single level axial lumbar interbody fusion (AxiaLIF) using a transsacral rod through a paracoccygeal approach has been developed with promising early clinical results and biomechanical stability. Recently, the transsacral rod has been extended to perform a two-level fusion at both L4–L5 and L5–S1 levels (AxiaLIF II). No biomechanical studies have been conducted on multilevel fusion using the AxiaLIF technique. In this study, the biomechanics of L4–S1 motion segments instrumented with the AxiaLIF II transsacral rod was evaluated. Six human cadaveric lumbosacral spine segments from L4 to S1 were used (age ranges 46–74 years). Unconstrained and non-destructive pure moments in axial torsion, lateral bending, and flexion extension were applied to each specimen following intact, standalone AxiaLIF II, and AxiaLIF II with two posterior fixation options: facet screws and pedicle screws with rods. Range of motion was calculated from the raw data collected with an optical motion tracking system. The two-level transsacral rod was successfully inserted in all the specimens. At L4–L5 level in axial torsion (AT) and flexion extension (FE), none of the surgical treatments showed statistically significant difference between the procedures (all P > 0.05) although facet screws and pedicle screws had higher stability on average. In lateral bending (LB), the two posterior fixation techniques had significantly higher construct stability (P < 0.05) than the standalone rod. No significant difference was found between facet screws and pedicle screws (P = 0.821). At L5–S1 level in AT and LB, none of the surgical treatments were found to be statistically significant (all P > 0.05). In FE, standalone two-level transsacral rod had significantly higher range of motion (ROM) compared with the posterior fixation techniques (P < 0.05). In conclusion, the standalone rod reduced intact ROM significantly. Supplementary fixations including facet screws and pedicle screws are required to achieve higher construct stability for successful fusion. Further clinical studies are essential to evaluate the practical success of this technique.     

Fetal tissue engineering from amniotic fluid

BACKGROUND: We have recently shown, in an animal model, that amniotic fluid can be a source of cells for fetal tissue engineering. This study was aimed at determining whether fetal tissue constructs could also be engineered from cells normally found in human amniotic fluid. STUDY DESIGN: Cells obtained from the amniotic fluid of pregnant women at 15 to 19 weeks of gestation (n=6) were cultured in Dulbecco's Modified Eagle's medium (Sigma Chemical, St Louis, MO) containing 20% fetal bovine serum and 5 ng/mL basic fibroblast growth factor in a 95% humidified, 5% CO(2) chamber at 37 degrees C. A subpopulation of morphologically distinct cells was then mechanically isolated from the rest and selectively expanded. The lineage of this subpopulation of amniocytes was determined by immunofluorescent staining with antibodies against standard intermediate filaments and surface antigens. Cell proliferation rates were determined by oxidation assay. After cell expansion, colonies of amniocytes were statically and dynamically seeded onto both unwoven, 1-mm-thick polyglycolic acid polymer scaffold and acellular human dermis for 72 hours. The resulting constructs were analyzed by scanning electron microscopy. RESULTS: Amniocytes stained positively for smooth muscle actin, vimentin, cytokeratin 18, and fibroblast surface protein, and negatively for desmin, cluster of differentiation 31, and von Willebrand's factor (Dako, Carpenteria, CA). These findings are consistent with a mesenchymal, fibroblast-myofibroblast cell lineage. Mesenchymal amniocytes could be rapidly expanded in culture, based on results of the proliferation assay. Scanning electron microscopy of amniocyte constructs revealed dense, confluent layers of cells surrounding the polymer matrices and firm cell adhesion to both PGA and Alloderm (Lifecell Corp, Branchburg, NJ) scaffolds. No evidence of cell death was observed. CONCLUSIONS: Subpopulations of fetal mesenchymal cells can be consistently isolated from human amniotic fluid and rapidly expanded in vitro. Human mesenchymal amniocytes attach firmly to both polyglycolic acid polymer and acellular human dermis. The amniotic fluid can be a valuable and practical cell source for fetal tissue engineering.     

Time does not heal all wounds: quality of life and psychological distress of people who survived the holocaust as children 55 years later

The present study assessed posttraumatic stress disorder (PTSD) symptoms, psychological distress, and subjective quality of life (QoL) in a group of 43 child Holocaust survivors and a community sample of 44 persons who had not personally experienced the Holocaust. The participants were administered the PTSD-Scale, the SCL-90, and the WHOQOL-Bref. Results showed that the child survivors had higher PTSD symptom scores, higher depression, anxiety, somatization, and anger–hostility scores; and lower physical, psychological, and social QoL than did the comparison group. The findings suggest that the psychological consequences of being a child during the Holocaust can be long lasting.     

Current determinants of operative mortality in 1400 patients requiring aortic valve replacement

BACKGROUND: Determinants of operative mortality after aortic valve replacement vary with a changing patient population due to advances in operative management and increasing life expectancy. In order to predict current groups of high risk patients, a statistically valid large study population base recruited over a short period of time is required. METHODS: Between January 1996 and June 2001, 1408 aortic valves were replaced in 1400 patients (572 of them with simultaneous coronary artery bypass grafting). The data were analyzed by multivariate logistic regression to evaluate the operative risk. Mean age of the study population was 68 +/- 11 years (range 19 to 90 years old, 44% female). RESULTS: Overall operative mortality (within 30 days) was 3.8%. Independent predictive factors for operative mortality were previous bypass surgery, emergency operation, simultaneous mitral valve replacement, renal dysfunction, more than 80 years old, simultaneous bypass surgery in female patients with a body mass index greater than 29 kg/m(2), and height smaller than 1.57 m for patients more than 71 years old. Simultaneous coronary artery bypass grafting in general (p = 0.6), previous aortic valve replacement (p = 0.59), and implantation of stented bioprostheses (p = 0.39) or stentless bioprostheses (p = 0.7) were not identified as independent risk factors. CONCLUSIONS: Certain groups of patients with a high operative risk were identified: patients more than 80 years old, women with a body mass index greater 29 kg/m(2) undergoing simultaneous coronary artery bypass surgery, and "small" patients more than 71 years old.     

Voxel-based diffusion tensor magnetic resonance imaging evaluation of low-grade hepatic encephalopathy

PURPOSE: To quantify the changes in brain water diffusivity in hepatic encephalopathy (HE) associated with cirrhosis using diffusion tensor imaging (DTI) and to correlate with neuropsychological (NP) scores. MATERIALS AND METHODS: DTI was performed in 14 patients with low-grade HE and age/gender-comparable 16 healthy controls. Whole brain mean diffusivity (MD) and fractional anisotropy (FA) maps were calculated, normalized to common space, smoothed, and compared voxel-by-voxel between groups using analysis of covariance with age included as a covariate. The average MD and FA values were also calculated from individual subjects for selected brain regions and correlated with the neuropsychological scores. RESULTS: Patients with HE showed increased MD in the cortical gray and white matter and the internal capsule. Less extensive brain regions with decreased FA were observed in the bilateral frontal and occipital white matter. MD values from the corpus callosum correlated inversely with several NP scores among HE patients and controls. Positive correlations were observed with FA values and cognitive scores. CONCLUSION: Voxel-based DTI analysis showed widespread brain regions with increased MD values, indicating enhanced water content and decreased FA in cirrhotic patients with HE. The MD and FA values from selected regions correlated with the NP scores.     

Prevalence of left atrial appendage pseudothrombus filling defects in patients with atrial fibrillation undergoing coronary computed tomography angiography

Background

Previous reports have shown that computed tomography (CT) is a useful, noninvasive test for detecting atrial thrombi. However, blood stasis in the left atrial appendage (LAA) of patients with atrial fibrillation (AF) may be a common cause for false-positive results.

Objectives

We retrospectively evaluated the prevalence of filling defects that may simulate thrombus in the LAA of patients with AF during routine coronary CT angiography (CTA).

Methods

The LAA of 7 patients with AF was studied for the presence of filling defects and compared with 250 healthy persons. LAA volume in the patients with AF was measured at 10 different cardiac phases and compared with 30 healthy patients.

Results

Of the 7 patients with AF studied with CTA, 5 were positive for LAA filling defects. Follow-up imaging studies, including transesophageal echocardiogram, contrast-enhanced magnetic resonance angiography, or delayed-CT, were negative for LAA thrombus. Of 250 patients without AF, CTA showed no evidence of LAA filling defects. Patients with AF had significantly larger LAA volumes at all cardiac phases measured compared with patients without AF (15.2 ± 6.93 mL compared with 6.85 ± 3.01 mL at atrial contraction [P = 0.0187], 17.4 ± 7.76 mL compared with 9.46 ± 3.43 mL at ventricular systole [P = 0.0351], and 14.5 ± 5.87 mL compared with 8.48 ± 3.10 mL at mid-diastole [P = 0.0341]). Compared with the healthy persons, the patients with AF showed reduced percentages of change in LAA volume when the atrial contraction phase was compared with other phases: 44.0% ± 25.6% compared with 16.5% ± 12.2% compared with ventricular systole (P = 0.0004) and 29.5% ± 23.7% compared with −1.63% ± 8.84% at mid-diastole (P < 0.0001).

Conclusions

Pseudothrombus filling defects are common in the LAA of patients with AF undergoing coronary CTA and should not be mistaken for real thrombus.     

Degeneration of non-fused segments after floating lumbar fusion

Degeneration of the disc or discs between two fused spinal segments has been termed "floating disc disease". The purpose of this retrospective study was to show the radiological evolution of the floating disc(s) and the relationship between floating disc degeneration and segmental lordosis, lumbar lordosis and pelvic incidence. Twenty patients, with a mean age of 49.9 years, with symptomatic lumbar degenerative disc disease or low grade spondylolisthesis, who failed non-operative treatment and underwent fusion of 2 or more noncontiguous spinal segments, were included in this study. The radiographs of the floating discs were graded with the modified Gore System. The mean follow-up was 4.2 years. Forty-seven levels were fused and 27 floating discs were studied (13 single, 7 double). Five out of 27 floating discs (18%), in 4 patients, progressively degenerated. None of the floating discs degenerated more than two radiographic grades and none needed additional surgery. Postoperatively, 3 out of 5 degenerated floating discs had decreased segmental lordosis, while the other two had no change; this difference was not significant (p = 0.08). Neither was there any significant correlation between floating disc degeneration and lumbar lordosis L1-S1 (p > 0.10) or pelvic incidence (p > 0.10). This study shows that the effect of floating fusion on floating discs is the same as the effect of a contiguous fusion on adjacent discs.