Grading the evidence for shortened intensive care unit stays after cardiac operations.
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Cardiac Surgical Procedures↗
Biomedical subjects
Robert G Johnson
Publications and source records attributed to Robert G Johnson.
Comparison of angioplasty and surgery for neonatal aortic coarctation.
BACKGROUND: The efficacy of balloon dilatation as primary treatment for neonatal aortic coarctation remains controversial. METHODS: A retrospective comparison between balloon angioplasty and surgery for the treatment of neonatal aortic coarctation was undertaken on 57 neonates younger than 40 days of age (angioplasty, 23 patients; surgery, 34 patients) treated between 1994 and 2004. RESULTS: Cohorts were similar with respect to the preinterventional variables of age, weight, upper extremity systolic blood pressure, coarctation gradient, degree of aortic arch hypoplasia, associated conditions, and mean follow-up (angioplasty, 36 months; surgery, 38 months). Among the angioplasty group, 13 patients (57%) required surgery, and 8 required a second balloon dilatation, of whom 3 patients had an aortic aneurysm. Among the surgery cohort, 6 patients experienced recurrence (18%) after either SFA (3) or XETE anastomosis repair (3). All were successfully treated with balloon angioplasty. Actuarial freedom from any intervention was significantly greater in the surgery cohort as was the degree of aortic arch growth. At latest follow-up, antihypertensive medication was required in 3 of 9 angioplasty patients (33%) and 2 of 27 surgery patients (7%). No repeat intervention was required in the 13 patients who underwent angioplasty followed by surgery. CONCLUSIONS: Primary angioplasty is palliative treatment for neonatal aortic coarctation, but it is the treatment of choice for recurrence after surgery. Surgery for neonatal aortic coarctation is associated with fewer reinterventions, improved aortic arch growth, no aortic aneurysm formation, and decreased need for antihypertensive medication when compared with neonates treated primarily with balloon angioplasty.
Angioplasty, Balloon↗
Internal thoracic artery flow competition: studies in a canine H-graft model.
OBJECTIVE: Internal thoracic artery (ITA) flow competition is a diversion of graft flow through intact ITA branches with a net decrease in perfusion to the grafted coronary. Although a widely acknowledged phenomenon, the conditions under which flow competition occurs have not been established. This is examined in a canine H-graft model. METHODS: Eight dogs had a right ITA segment interposed (H-graft) between their in situ left ITA (LITA) and the snared left anterior descending (LAD) coronary artery. Proximal LITA and H-graft flows were measured at baseline and during pacing-induced tachycardia, phenylephrine-induced hypertension, and nitroprusside-induced hypotension. Flows were measured with the distal LITA open and occluded. Two additional animals were subjected to eight separate 2-min periods of LAD ischemia, after which post-ischemic H-graft flow measurements were obtained with and without distal LIMA occlusion. RESULTS: During baseline conditions, proximal LITA flow was greater when the distal LITA was open rather than occluded (46+/-15 versus 35+/-12 ml/min, respectively; P=0.002), but H-graft flow did not change significantly (32+/-18 versus 35+/-18 ml/min, respectively; P=0.21). Similarly, occlusion of the distal LITA had no impact on H-graft flow during tachycardia, hypertension, or hypotension. Only in animals subjected to transient LAD ischemia did H-graft flow increase with distal LITA occlusion, albeit marginally (65+/-7-70+/-9 ml/min, occluded versus open, respectively; P=0.04). CONCLUSIONS: Mild diversion of flow from the LAD was demonstrated during immediate post-ischemic coronary reperfusion only, and could not be elicited under any other physiologic condition. These data suggest that flow competition is unlikely to constitute a clinically significant limitation to the use of H-grafts or other modalities that leave ITA branches patent.
Animals↗
Clinical and economic outcomes of multivessel coronary stenting compared with bypass surgery: a single-center US experience.
BACKGROUND: Randomized trials comparing multivessel stenting with coronary artery bypass surgery (CABG) have demonstrated similar rates of death and myocardial infarction but higher rates of repeat revascularization after stenting. The impact of these alternative strategies on overall medical care costs is uncertain, particularly within the US health care system. METHODS: We performed a retrospective, matched cohort study to compare the clinical and economic outcomes of multivessel stenting and bypass surgery. The stent group consisted of 100 consecutive patients who underwent stenting of >or=2 major native coronary arteries at our institution. The CABG group consisted of 200 patients who underwent nonemergent isolated bypass surgery during the same time frame, matched (2:1) for age, sex, ejection fraction, diabetes mellitus, and extent of coronary disease. Detailed clinical follow-up and resource utilization data were collected for a minimum of 2 years. Total costs were calculated by use of year 2000 unit prices. RESULTS: Over a median follow up period of 2.8 years, there were no significant differences in all-cause mortality rates (3.0% vs 3.0%), Q-wave myocardial infarction (5.1% vs 4.0%), or the composite of death or myocardial infarction (7.1% vs 7.0%) between the stent and CABG groups (P = not significant for all comparisons). However, at 2-year follow up, patients with stents were more likely to require >or=1 repeat revascularization procedure (32.0% vs 4.5%, P <.001). The initial cost of multivessel stenting was 43% less than the cost of CABG (11,810 dollars vs 20,574 dollars, P <.001) and remained 27% less (17,634 dollars vs 24,288 dollars, P =.005) at 2 years. CONCLUSIONS: Multivessel stenting and CABG result in comparable risks of death and myocardial infarction. Despite a higher rate of repeat revascularization, multivessel stenting was significantly less costly than CABG through the first 2 years of follow-up.
Angioplasty, Balloon, Coronary↗
A modified VSP screw: two-year experience.
A new pedicle screw was designed to address the insertion limitations of the existing VSP and TIMX screws. In the standard VSP insertion technique, the T-handle wrench has an enlarged foot, which contacts the superior facet and interferes with countersinking the fixed nut. The hex of the machine screw may strip in hard bone. The hexagonal design of the fixed nut may make explantation difficult. The evolution of the VSP into the TIMX addresses some of these issues. However, the screw design still has problems. The tapered spacer extends beyond the diameter of the fixed nut and must be applied after the screw is inserted. The flattening of the machine thread requires rotational alignment of the screws before the plate can be inserted. The design does not allow for easy placement of the acorn nut. The modified VSP screw preserves the superior facet, allows for countersinking, permits application of the spacer prior to insertion, and facilitates application of the acorn nut. Rotational alignment of the screw is not required to accommodate the plate. The surgeon can save time and effort inserting and explanting the modified VSP screw.
Bone Screws↗
T-Coupler: a method of in situ coupling of plate-plate and rod-plate: a technical report.
BACKGROUND CONTEXT: With the existing VSP plate using "no-cut," or low profile screws, with a 5-mm spacer on the screw, it is difficult or impossible to stack a second plate onto the existing in situ plate. In order to extend a fusion above or below, the plate must be explanted and replaced with a longer plate. PURPOSE: Situations exist where it would be advantageous to leave an existing plate in situ and couple a second plate onto the existing plate. A new device is described for in situ coupling of a plate to plate and a rod to plate using the VSP and lsola systems. STUDY DESIGN: A T-Coupler was designed to permit coupling of plate-to-plate and rod-to-plate. The T-Coupler was implanted into patients who were prospectively followed clinically and radiographically for a minimum of 2 years. PATIENT SAMPLE: Seventeen patients were selected who were deemed candidates for the above procedure. In each case, the patient had an existing fusion with Steffee plate and required extension of the fusion above or below the existing plate. OUTCOME MEASURES: The patients were followed clinically and radiographically for a minimum 2 years. METHODS: After obtaining FDA 510K clearance and appropriate mechanical testing, the T-Coupler was implanted into patients who were deemed appropriate candidates. In each case the patient had an existing fusion with a Steffee plate and required an extension of the fusion above or below. The patients were followed with anterior-posterior and flexion/extension lateral films every 3 months for 2 years and then every 6 months. The patient's clinical progress was also evaluated. RESULTS: The T-Coupler was used in 18 operations in 17 patients with a minimum follow-up of 24 months, an average follow-up of 49.6 months with a range of 24 to 84 months. Three patients underwent reexploration with direct visualization of the T-Coupler. There was no evidence of loosening or breakage, and radiographically all patients went on to solid fusions. CONCLUSIONS: The T-Coupler is a safe and effective device for the stacking of plates or rods onto an existing plate in selected patients. The T-Coupler may improve patient care by reducing the need to explant long constructs thereby reducing operating time, blood loss, and risk of infection.
Bone Plates↗
Cardiac surgery in the newborn: improved results in the current era.
Pediatric cardiovascular surgeons can now safely operate on newborns to palliate or completely correct congenital heart defects in babies as small as 1.5-2.0 kilograms. The various cardiac anomalies treated can be categorized with respect to their dependency on a patent ductus arteriosus for systemic or pulmonary blood flow. The early results are directly linked to the complexity of the congenital defect, but are generally good so long as the intervention can provide two functional ventricular chambers. Although great strides have been made, continued progress in the treatment of neonates with congenital heart defects remains challenging and requires the collaborative effort between pediatricians, perinatologists, neonatologists, interventional cardiologists, pediatric cardiovascular surgeons and intensive care unit nurses.
Cardiac Surgical Procedures↗