Rapid prototyping facilitates comprehension of complex cardiac anatomy. However, determining when this additional information proves instrumental in patient management remains a challenge. We describe our experience with patient-specific anatomic models created using rapid prototyping from various imaging modalities, suggesting their utility in surgical and interventional planning in congenital heart disease (CHD). Virtual and physical 3-dimensional (3D) models were generated from CT or MRI data, using commercially available software for patients with complex muscular ventricular septal defects (CMVSD) and double-outlet right ventricle (DORV). Six patients with complex anatomy and uncertainty of the optimal management strategy were included in this study. The models were subsequently used to guide management decisions, and the outcomes reviewed. 3D models clearly demonstrated the complex intra-cardiac anatomy in all six patients and were utilized to guide management decisions. In the three patients with CMVSD, one underwent successful endovascular device closure following a prior failed attempt at transcatheter closure, and the other two underwent successful primary surgical closure with the aid of 3D models. In all three cases of DORV, the models provided better anatomic delineation and additional information that altered or confirmed the surgical plan. Patient-specific 3D heart models show promise in accurately defining intra-cardiac anatomy in CHD, specifically CMVSD and DORV. We believe these models improve understanding of the complex anatomical spatial relationships in these defects and provide additional insight for pre/intra-interventional management and surgical planning.
Whether cosmetically acceptable tumor-free (>/=2 mm) surgical margins reduce the local-regional recurrence risk for patients treated with fractionated radiation therapy, chemotherapy, and hormonal therapy is unknown. The benefit of a minimum cosmetically acceptable tumor-free margin remains speculative because no contemporary studies have investigated the extent of invasive disease infiltration within the breast beyond the primary tumor. To address these clinical issues, we conducted a retrospective study of 341 women diagnosed with stage I or II invasive breast cancer to determine the rate of local in-breast, elsewhere in-breast, and ipsilateral regional lymph node recurrences of breast cancer after conservation surgery achieving either tumor-free (>or=2 mm) or close (>0 mm to <2 mm) surgical margins followed by whole breast radiation therapy over a 6-year period from January 1996 to December 2002. Women may have received adjuvant chemotherapy or hormonal therapy as clinically indicated. After a median follow-up of 56 months from the completion of breast conservation surgery, 14 of the 341 women (4.1%) developed breast cancer recurrences. Crude ipsilateral recurrence rates were 1.8% (4 of 222) for tumor-free (>or=2 mm) versus 8.4% (10 of 119) for close (>0 mm to <2 mm) surgical margins (p=0.007). The estimated 5-year cumulative local recurrence rate was significantly less for women with tumor-free margins (2.1%) as compared to close surgical margins (8.9%) (p=0.004). Multivariate analyses identified negative estrogen receptor expression (p=0.004), close surgical margins (p=0.012), and the presence of angiolymphatic invasion (p=0.040) as prognostic factors for local-regional recurrences. Microscopically the extent of invasive disease infiltration beyond the primary tumor was on average 1 mm, with all measured invasive disease less than 1 cm. Based on our findings, cosmetically acceptable tumor-free (>or=2 mm) surgical margins significantly reduce local in-breast and regional lymph node recurrences with fractionated radiation therapy, chemotherapy, and hormonal therapy.
Background: Percutaneous transcatheter pulmonary valve replacement (TPVR) has good clinical and hemodynamic outcomes in treating dysfunctional bioprosthetic valves (BPV) in the pulmonary position. Valve-in-valve therapy can further decrease the inner diameter (ID), potentially resulting in patient-prosthesis mismatch in patients with smaller BPVs. Methods and Results: To evaluate feasibility and outcomes of intentional BPV fracture to enlarge the pulmonary valve orifice with TPVR, 37 patients from 13 centers who underwent TPVR with intended BPV fracture were evaluated. A control cohort (n=70) who underwent valve-in-valve TPVR without attempted fracture was evaluated. BPV was successfully fractured in 28 patients and stretched in 5 while fracture was unsuccessful in 4. A Melody valve was implanted in 25 patients with fractured/stretched frame and a Sapien (XT 3) valve in 8. Among patients whose BPV was fractured/stretched, the final ID was a median of 2 mm larger (0–6.5 mm) than the valve’s true ID. The narrowest diameter after TPVR in controls was a median of 2 mm smaller ( P <0.001) than true ID. Right ventricular outflow tract gradient decreased from median 40 to 8 mm Hg in the fracture group. Cases with fracture/stretching were matched 1:1 (weight, true ID) to controls. Post-TPVR peak gradient was lower but not significant (8.3±5.2 versus 11.8±9.2 mm Hg; P =0.070). There were no fracture-related adverse events. Conclusions: Preliminary experience shows intentional fracture of BPV frame can be useful for achieving larger ID and better hemodynamics after valve-in-valve TPVR.
To eliminate the need for intramyocardial transducers in measuring regional left ventricular (LV) function we have developed a pulsed Doppler technique utilizing a single epicardial transducer. Wall thickening is evaluated by digitally integrating the velocity of myocardial layers passing through the sample volume located at a selected depth. Thickening fraction (TF) can then be estimated by dividing the systolic excursion by the sample volume depth. The Doppler method was compared with the transit-time method in three acute dogs by placing the 4-mm-diameter epicardial Doppler transducer over a 2-mm-diameter endocardial crystal tunneled through the LV wall. With the sample volume set to 1 mm less than the minimum LV thickness, simultaneous measurements of TF by the Doppler and transit-time methods showed good agreement (r = 0.95) during control, ischemia, volume overload, shock, and anoxia. In 28 chronically instrumented piglets signals were obtained for longer periods with Doppler transducers than with transit-time segment-length crystals. We conclude that the Doppler technique provides a high-fidelity wall thickening waveform and a good estimate of TF with minimal disturbance to the ventricle and that the technique is suitable for use in both acute and chronically instrumented animals.
Osteogenic Protein-1 (OP-1, BMP-7) acts locally on connective tissue progenitors (CTPs) to induce bone formation. The response to OP-1 and similar agents is potentially limited by the number of local CTPs. This study tested the hypothesis that supplementing local CTPs using autogenous bone marrow will enhance bone formation at an OP-1 implant. Four 1.0-cm diameter unicortical cylindrical defects in the left proximal femur were grafted in each of seven dogs. Radial ingrowth of new bone formation was assessed at 4 weeks using micro CT. The OP-1 (3.5 mg rhOP-1 in 1 g bovine collagen I matrix) was implanted in each site combined with either clotted blood or aspirated bone marrow (BM). Bone formation was increased in the group augmented with transplanted marrow. These data suggest that increasing the local population of cells and CTPs using aspirated bone marrow can enhance the performance of OP-1, but may not eliminate the effects of site variation on the response to OP-1 and similar agents. The canine multiple femoral defect model defined in this study is well suited to quantitatively evaluate strategies for augmenting bone repair using local cell targeting and cell transplantation strategies. ß
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