Are postoperative standing radiographs relevant before hospital discharge in adolescent idiopathic scoliosis?

PURPOSE

Postoperative standing radiographs are usually performed before hospital discharge after AIS fusion. However, patients are often still painful and have not recovered yet their physiological balance. The aim of this study was therefore to evaluate the relevance of such early radiographs and more specifically investigate whether postoperative alignment could be analyzed.

METHODS

All consecutive AIS patients operated between January 2015 and December 2015 were included. All patients underwent biplanar stereoradiographs before hospital discharge, at 4 months postoperative and at last follow-up. Fifteen parameters (eight coronal and seven sagittal), reflecting correction and spinal alignment were measured and compared. The incidence of implant misplacement, requiring or not surgical revision, was recorded.

RESULTS

In total, 100 patients were included. A significant difference was found for 12 out of the 15 (80%) parameters between the first erect radiograph and the 4-month follow-up visit, including the CVA and the SVA, which are commonly used to assess postoperative alignment. Clavicle, UIV and LIV tilts also decreased significantly at 4 months postoperative. In opposition, no significant change occurred for the same parameters between the 4-month visit and latest follow-up. In nine patients, a pedicle screw was considered misplaced on the first radiograph, but all patients remained asymptomatic and no revision was performed.

CONCLUSION

There is no need for additional immediate postoperative radiographs in AIS, if an intraoperative radiograph has already been taken. This finding could help reducing radiation exposure in immature patients and should be further studied in other etiologies. These slides can be retrieved under Electronic Supplementary Material.

Clinical experience with a single-nucleotide polymorphism-based non-invasive prenatal test for five clinically significant microdeletions

Single-nucleotide polymorphism (SNP)-based non-invasive prenatal testing (NIPT) can currently predict a subset of submicroscopic abnormalities associated with severe clinical manifestations. We retrospectively analyzed the performance of SNP-based NIPT in 80 449 referrals for 22q11.2 deletion syndrome and 42 326 referrals for 1p36, cri-du-chat, Prader-Willi, and Angelman microdeletion syndromes over a 1-year period, and compared the original screening protocol with a revision that reflexively sequenced high-risk calls at a higher depth of read. The prevalence of these microdeletion syndromes was also estimated in the referral population. The positive predictive value of the original test was 15.7% for 22q11.2 deletion syndrome, and 5.2% for the other 4 disorders combined. With the revised protocol, these values increased to 44.2% for 22q11.2 and 31.7% for the others. The 0.33% false-positive rate (FPR) for 22q11.2 deletion syndrome decreased to 0.07% with the revised protocol. Similarly, the FPR for the other 4 disorders combined decreased from 0.56% to 0.07%. Minimal prevalences were estimated to be 1 in 1255 for 22q11.2 deletion syndrome and 1 in 1464 for 1p36, cri-du-chat, and Angelman syndromes combined. Our results show that these microdeletions are relatively common in the referral population, and that the performance of SNP-based NIPT is improved with high-depth resequencing.

Dynamic balance assessment during gait in spinal pathologies - a literature review

The role of the spine as a gait stabilizer is essential. Dynamic assessment, while walking, might provide complementary data to improve spinal deformity management. The aim of this paper was to review spine dynamic behavior and the various methods that have been used to assess gait dynamic balance in order to explore the consequences of spinal deformities while walking. A review was performed by obtaining publications from five electronic databases. All papers reporting pathological or non-pathological spine dynamic behavior during gait and dynamic balance assessment methods were included. Sixty articles were selected. Results varied widely according to pathologies, study conditions, and balance assessment techniques. Three methods assessing dynamic stability during gait were identified: local-orbital dynamic stability, tri-axial accelerometry, and dynamic stability margin. Data from conventional gait analysis techniques were established essentially for scoliosis and low back pain, but they do not assess specific consequences on gait dynamic balance. Three techniques investigate gait dynamic balance and have been validated in normal subjects. Further investigations need to be performed for validation in spinal pathologies as well as the value for clinical practice.

LEVEL OF EVIDENCE

Level IV.

Contribution of domain interface residues to the stability of antibody CH3 domain homodimers

Dimers of CH3 domains from human IgG1 were used to study the effect of mutations constructed at a domain-domain interface upon domain dissociation and unfolding, "complex stability". Alanine replacement mutants were constructed on one side of the interface for each of the sixteen interdomain contact residues by using a single-chain CH3 dimer in which the carboxyl terminus of one domain was joined to the amino terminus of the second domain via a (G4S)4 linker. Single-chain variants were expressed in Escherichia coli grown in a fermentor and recovered in yields of 6-90 mg L-1 by immobilized metal affinity chromatography. Guanidine hydrochloride-induced denaturation was used to follow domain dissociation and unfolding. Surprisingly, the linker did not perturb the complex stability for either the wild type or two destabilizing mutants. The CH3 domain dissociation and unfolding energetics are dominated by six contact residues where corresponding alanine mutations each destabilize the complex by >2.0 kcal mol-1. Five of these residues (T366, L368, F405, Y407, and K409) form a patch at the center of the interface and are located on the two internal antiparallel beta-strands. These energetically key residues are surrounded by 10 residues on the two external beta-strands whose contribution to complex stability is small (three have a Delta DeltaG of 1.1-1.3 kcal mol-1) or very small (seven have a Delta DeltaG of </=0.7 kcal mol-1). Thus, at the center of the CH3 structural interface there is a small "functional interface" of residues that make significant contributions to complex stability.

Long-term oral acyclovir therapy. Effect on recurrent infectious herpes simplex keratitis in patients with and without grafts

PURPOSE

To evaluate the efficacy of long-term oral acyclovir therapy in reducing recurrences of dendritic or geographic herpes simplex keratitis (HSK).

METHODS

Thirteen patients with a history of frequently recurring HSK were followed before (mean, 27 months) and during long-term systemic acyclovir, and eight were followed after the acyclovir was discontinued.

RESULTS

Treatment ranged from 8.5 to 62 months (mean, 34 months). During treatment, the number of recurrences per month decreased from 0.15 to 0.03, and the average duration of relapses decreased from 12.6 to 7.8 days. Recurrences correlated with daily doses of oral acyclovir of 800 mg or less, intraocular surgery within 6 weeks of initiating treatment, and discontinuation of therapy against medical advice.

CONCLUSION

The results of this small study appear to demonstrate the efficacy of long-term oral acyclovir in prophylaxis of recurrent epithelial herpes simplex infection: therapeutic doses of oral acyclovir reduce both the rate and duration of recurrences of infectious herpetic keratitis. A multicenter, double-masked, placebo-controlled study is indicated.

Flow cytometric analysis of relative mean DNA content of urogenital cancer cells in fresh and paraffin-embedded materials

The relative mean DNA content calculation was performed by flow cytometry on single cell suspensions prepared from fresh and paraffin-embedded specimens of 10 patients with surgically resected urogenital cancer. Samples were processed by a modified method of Hedley et al. including two hours of pepsinizing time, ribonuclease digestion, and propidium iodide staining. The mean DNA content which is a quantitative description of flow cytometric characteristics was significantly correlated between the fresh and paraffin-embedded materials (n = 10, r = 0.869, p less than 0.01). This method allows for the objective, retrospective analysis of DNA content in relation to diagnosis and prognosis of urogenital cancer.

Juxtaductal aortic coarctation. Analysis of 84 patients studied hemodynamically, angiographically, and morphologically after age 1 year

Although many studies of juxtaductal coarctation of the aorta have been reported, none has correlated clinical, hemodynamic, angiographic, anatomic, and operative findings. Of 84 patients (62 male and 22 female; age range, 1 to 49 years [mean 17]), all had murmurs; 76 had absent, diminished, or delayed femoral pulsations; 50 had cuff systolic blood pressures in the arm greater than 140 mm Hg, and 30 had diastolic pressures greater than 90 mm Hg. The average pressure gradients (mm Hg) by direct measurements above and below the coarctation in 35 patients were peak systolic, 45; mean, 17; and diastolic, 5. Rib notching, visible in chest roentgenograms in 43 patients, correlated directly with age and inversely with the diameter of the coarctation. Moderate or marked cardiomegaly by radiograph was present in only 1 of 48 patients with isolated coarctation and in 17 of 36 with associated cardiovascular malformations. Electrocardiograms were abnormal in more than two thirds of patients with associated anomalies, but were normal in more than three fourths of those with isolated coarctation. In 70 excised, serially sectioned coarctations the aortic lumens were completely occluded in 4 patients, up to 0.5 mm in internal diameter in 22 patients, from 0.6 to 2 mm in 26 patients, from 2.1 to 5 mm in 14, and greater than 5 mm in 4, and correlated directly with lumens measured angiographically. The most significant anatomic factor causing the coarctation was invagination of the media from the posterior aortic wall, but intimal proliferation (jet lesion) at and immediately distal to the invagination contributed to the narrowing. Three (each with associated anomalies) of 70 patients died early after coarctation repair. Systolic or diastolic blood pressures decreased early postoperatively in 58 (87%) of 67 surviving patients, and both pressures decreased in 42 (63%). Late postoperatively (mean follow-up, 4.7 years), the systolic blood pressure remained elevated in 25% of patients.

Localization of the conduction delay occurring during coronary arteriography

The effect of coronary arteriography on intraventricular conduction was studied in 12 atropinized, open-chest dogs. Left bundle-branch (LB) and cavitary (V) potentials were recorded from a bipolar electrode catheter positioned against the septum below the aortic valve. Subendocardial (SEE) and subepicardial (IME) bipolar potentials were obtained from distal and proximal poles of multipolar electrode needles. Conduction times from LB to V, LB or V to SEE and SEE to IME were obtained during control and during Renografin 76 (REN) and normal saline injections into the left and right coronary arteries. Significant QRS axis changes and increased QRS duration occurred in 6 of 12 dogs simultaneously with LB-SEE and V-SEE delay. In 6 without axis changes, REN produced significant delay and increased QRS duration. Only REN to LCA produced significant changes. Coronary arteriography alters conduction through the distal left ventricular Purkinje system without affecting transmural conduction.

Catheter positions in congenital cardiac malformations

Biplane cineangiocardiograms were examined from a population of patients with diverse forms of congenital heart disease and examples were selected to illustrate catheter positions which may help define and elucidate the anatomy of simple and complex cardiac lesions. Familiarity with the appearance of these typical and atypical catheter positions may be of considerable aid in the course of hemodynamic study and in the evaluation of cineangiocardiograms. The editors suggest that each figure be evaluated as an unknown before reading the caption.

Correlations between the chest film and hemodynamics in acute myocardial infarction

A series of 169 standardized chest films was analyzed relative to hemodynamic parameters obtained within 2 hr of the roentgenogram in 86 patients with acute myocardial infarction. The films were evaluated for cardiomegaly using the cardiothoracic ratio and the standardized, external left heart dimension. The radiographic appearance of the pulmonary vasculature was divided into levels of increasing severity: normal, pulmonary venous congestion, interstitial pulmonary edema, alveolar pulmonary edema. These were compared with wedge pressure levels of ⪕12, 13-18, 19-25, and >25 mm Hg, respectively. Correlations with the admission films of the 86 patients showed: 1) The appearance of the pulmonary vasculature accurately predicted the patient's wedge pressure on admission in 43% of the cases, overestimated it in 33% and underestimated it in 24%. 2) The presence of cardiomegaly and/or pleural effusion indicated an elevated wedge pressure with a high degree of certainty; however the absence of these signs did not exclude an elevated wedge pressure. 3) In only 62% of the studies was the chest film able to detect or exclude the presence of pulmonary venous hypertension. However, when wedge pressures were elevated to 19-25 mm Hg and over 25 mm Hg, 74% and 100%; respectively of roentgenograms had some evidence of pulmonary venous hypertension. 4) There was a high degree of correlation between the patient's admission physical findings, as evidenced by clinical classification, and the radiologic assessment of pulmonary venous hypertension.

There was no statistical variation in the accuracy of the estimate of wedge pressure in relation to the time elapsed from onset of symptoms of myocardial infarction. However, a therapeutic phase lag was encountered in 21 patients, the chest films remaining abnormal for a period of 1 to 4 days following return of the wedge pressure to normal. A diagnostic phase lag was encountered in 6 patients in whom the chest film did not correlate with elevation of wedge pressure for up to 12 hr. Furthermore, in 17 patients the films were normal in spite of a persistently elevated wedge pressure for 6 to 24 hr.

These studies document the limitations of the chest roentgenogram in predicting the hemodynamic status of patients with acute myocardial infarction.

Left ventricular size after acute myocardial infarction. Serial changes and their prognostic significance

The distance from the midline to the left heart border measured in a standardized manner on calibrated chest roentgenograms was determined serially in 125 patients after acute myocardial infarction. This external left heart dimension (LHD) was compared to the normal value, and its prognostic value was assessed during early and late follow-up periods (average 10½, range 2-31 months). Within 96 hours after acute myocardial infarction the initial LHD was enlarged (>52 mm/m 2 BSA [body surface area]) in 42% of the patients. The LHD became normal, or remained persistently normal in 60% of the 115 patients without shock, and it became enlarged or remained persistently enlarged in 40%. If the 10 patients with cardiogenic shock are excluded, early death (<4 weeks) occurred in three of 68 patients (4%) with initially normal LHD, and in 12 of 47 patients (26%) with initially enlarged LHD ( P < 0.001). The LHD remained normal or became normal in 62 of 96 patients followed who survived more than 1 month. During the follow-up period, 8% of patients with a normal LHD have died and the remainder (with one exception) are in New York Heart Association (NYHA) class I or II. Only 5% of this group died of acute cardiac causes. In 34 patients the LHD became or remained persistently enlarged; of these patients 24% have expired ( P < 0.05) and 42% are in NYHA class III ( P < 0.001). This study validates a method for the early detection and serial assessment of left ventricular enlargement and indicates that the LHD is a useful predictor of survival and morbidity after acute myocardial infarction.

Myocardial perfusion imaging with radioactive-labeled particles injected directly into the coronary circulation of patients with coronary artery disease

Macroaggregated serum albumin (MAA) particles labeled with 131 iodine ( 131 I) or similar particles-labeled with 99m technetium ( 99m Tc) or both types were injected directly into the coronary circulation of 29 patients at the time of conventional coronary arteriography. Radionuclide images of the distribution of these small (10-60 µ) biodegradable particles in the small vessels of the heart wall were made with a commercial Anger-type scintillation camera in much the same way as routine pulmonary perfusion scans are made. The resulting images depicted the relative regional distribution of blood flow to the myocardium in these patients suspected of having coronary artery disease. The myocardial perfusion images were of good quality and allowed gross assessment of perfusion by way of each major coronary artery. This was done by injecting 99m Tc-labeled particles into the left coronary artery and 131 I-MAA into the right coronary artery through the coronary artery catheter. Separate or composite images of the relative small vessel perfusion via each vessel injected were obtained by electronic pulse-height discrimination. No untoward reactions followed the intracoronary injection of the labeled particles. From our preliminary experience, we conclude that myocardial perfusion imaging in conjunction with coronary arteriography may prove to be a valuable diagnostic tool in the evaluation of the regional vascular supply to the heart in patients with coronary artery disease.

Congenital fixed subvalvular aortic stenosis. An anatomical classification and correlations with operative results

Detailed assessments were carried out before and after operation in 33 consecutive patients with congenital fixed subvalvular aortic stenosis. Effective relief of obstruction to left ventricular outflow can be accomplished at minimal risk in patients with discrete subaortic stenosis, but a pressure gradient may persist after operation because of secondary hypertrophic obstruction which resolves with time. Tunnel subaortic stenosis is characterized by a diffusely narrowed left ventricular outflow tract. When an intraventricular pressure gradient was present in such patients, good but not complete relief of obstruction was achieved. In tunnel deformities with a gradient at the valve or annulus and in subaortic stenosis produced by mitral valve anomalies, operative intervention was ineffective.

Clinical and laboratory findings in patients with nonobstructive intraventricular pressure differences

Clinical and laboratory findings were examined in eight patients with nonobstructive intraventricular pressure differences resulting from catheter entrapment in obliterated apical portions of the left ventricular cavity. Cardiorespiratory symptoms were reported by six of the eight patients; three had angina pectoris, and two had experienced syncope. A soft systolic ejection murmur was noted at the cardiac apex or left sternal edge, or at both sites, in each patient at rest or following exercise; no patient had a bifid systolic arterial pulse contour. Paradoxical splitting of the second heart sound with respiration did not occur. In five patients the cardiac index was substantially elevated. In four, an intraventricular pressure difference was present in the basal state, while in the remaining four a pressure difference was elicited by the Valsalva maneuver and isoproterenol. In each patient the arterial pulse pressure consistently increased in the beat following a ventricular extrasystole, and angiographic evidence of left ventricular outflow obstruction was not observed. In all patients, obliteration of the apical portion of the left ventricular cavity during systole was demonstrated angiographically to result from an extreme degree of systolic emptying. Left ventricular hypertrophy was demonstrated angiographically in six patients, four of whom exhibited asymmetric hypertrophy, predominantly involving the interventricular septum. In two patients no abnormality of the left ventricular cavity contour was apparent. These clinical, hemodynamic, and angiographic findings allow differentiation of patients with nonobstructive pressure differences from those with hypertrophic subaortic stenosis.

Angiographic anatomy of the left ventricle and mitral valve in idiopathic hypertrophic subaortic stenosis

The angiographic features of the left ventricle were examined in patients with idiopathic hypertrophic subaortic stenosis who had clinical and hemodynamic evidence of obstruction. Of 36 combined hemodynamic and angiographic studies considered to be technically satisfactory, 33 showed a characteristic combination of abnormalities. In the frontal projection in systole, a linear radiolucent area extended across the left ventricular outflow tract 2 to 2.5 cm below the aortic annulus, at a level corresponding to the site of intraventricular pressure change. In the left oblique and lateral projections, the mitral leaflets did not swing posteriorly in a normal fashion, but projected into the outflow tract during mid and late systole. The radiolucent line, seen in the frontal views, was considered to represent contact of the leading edge of the leaflet with the hypertrophied muscular interventricular septum. The jet of mitral regurgitation, when present, was seen immediately below the anterior mitral leaflet.

Severe hypertrophy was also seen to involve the inferior portion of the muscular septum, causing displacement of the papillary muscles superiorly and to the left. This maldirection of the papillary muscles was postulated to cause abnormal traction on the chordae tendineae and to prevent normal movement of the mitral leaflets away from the septum during systole. The leaflets, held in the outflow tract, form the posterior component of the obstruction, the anterolateral component of which results from severe, asymmetric septal hypertrophy. It was proposed that this mechanism plays an important part in producing the intraventricular pressure gradient in many patients with idiopathic hypertrophic subaortic stenosis.