Allan M Lansing

Baylor Health Care System, Dallas, Texas, United States

Are you Allan M Lansing?

Claim your profile

Publications (5)22.86 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Transmyocardial laser revascularization (TMR) using a carbon dioxide (CO(2)) laser has been shown to relieve angina, increase vascular density, and improve myocardial contraction. A study of 28 patients receiving TMR was conducted to monitor vascular endothelial growth factor (VEGF) levels with the goal of clarifying the relationship between TMR, the amelioration of angina, and vascular density. Serum VEGF levels were measured during four periods (preoperative, postoperative, convalescence, and late) in these 28 patients who received sole therapy TMR for un-revascularizable ischemic angina and the levels were compared with the control group consisting of 10 nonischemic thoracotomy patients. Twelve of the 28 patients had previous coronary artery bypass graft(s); 10 had unstable angina, and 1 had an ejection fraction less than 30%. Overall, angina class was reduced from 3.8 +/- 0.9 to 1.0 +/- 0.9 (P < 0.01) at the 1-year follow-up. There were no perioperative mortalities; however, there was one late mortality. The results show that VEGF levels were higher in the convalescence and late periods. Specifically in the late period, VEGF levels in TMR therapy patients surpassed those of the control group and normalized VEGF levels were three times higher in the late period than preoperatively. The sustained VEGF secretion observed in this study may help to explain why CO(2) TMR therapy causes locally increased vascular density and angina relief.
    Seminars in Thoracic and Cardiovascular Surgery 02/2006; 18(1):43-5.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We evaluated transmyocardial laser revascularization (TMLR) with coronary artery bypass grafting (CABG) versus CABG alone for severe coronary artery disease involving 21 myocardial region unsuited for CABG. At 4 centers, 44 consecutive patients were randomized for CABG+TMLR (n = 23) or CABG alone (n = 21). Operative and in-hospital mortality and morbidity rates were monitored. Clinical status was evaluated at hospital discharge, 1 year, and 4 years. Success was characterized by relief of angina and freedom from repeat revascularization and death. Preoperatively, 20 patients (47%) were at high risk. The CABG technique, number of grafts, and target vessels were similar in both groups. Patients undergoing CABG+TMLR received 25 +/- 11 laser channels. Their < or = 30-day mortality was 13% (3/23) compared with 28% (6/21) after CABG alone (P = 0.21). There were no significant intergroup differences in the number of intraoperative or in-hospital adverse events. The follow-up period was 50.3 +/- 17.8 months for CABG alone and 48.1 +/- 16.8 months for CABG+TMLR. Both groups had substantially improved angina and functional status at 1 and 4 years, with no significant differences in cumulative 4-year mortality. The incidence of repeat revascularization was 24% after CABG alone versus none after CABG+TMLR (P < 0.05). The 4-year event-free survival rate was 14% versus 39%, respectively (P < 0.064). In conclusion, CABG+TMLR appears safe and poses no additional threat for high-risk patients. Improved overall success and repeat revascularization rates may be due to better perfusion of ischemic areas not amenable to bypass. Further studies are warranted to determine whether these trends are indeed significant.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2004; 31(3):231-9. · 0.67 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although transmyocardial laser revascularization (TMR) has provided symptomatic relief of angina over the short term, the long-term efficacy of the procedure is unknown. Angina symptoms as assessed independently by angina class and the Seattle Angina Questionnaire (SAQ) were prospectively collected up to 7 years after TMR. Seventy-eight patients with severe angina not amenable to conventional revascularization were treated with a CO(2) laser. Their mean age was 61+/-10 years at the time of treatment. Preoperatively, 66% had unstable angina, 73% had had >/=1 myocardial infarction, 93% had undergone >/=1 CABG, 42% had >/=1 PTCA, 76% were in angina class IV, and 24% were in angina class III. Their average pre-TMR angina class was 3.7+/-0.4. After an average of 5 years (and up to 7 years) of follow-up, the average angina class was significantly improved to 1.6+/-1 (P=0.0001). This was unchanged from the 1.5+/-1 average angina class at 1 year postoperatively (P=NS). There was a marked redistribution according to angina class, with 81% of the patients in class II or better, and 17% of the patients had no angina 5 years after TMR. A decrease of >/=2 angina classes was considered significant, and by this criterion, 68% of the patients had successful long-term angina relief. The angina class results were further confirmed with the SAQ; 5-year SAQ scores revealed an average improvement of 170% over the baseline results. The long-term efficacy of TMR persists for >/=5 years. TMR with CO(2) laser as sole therapy for severe disabling angina provides significant long-term angina relief.
    Circulation 09/2001; 104(12 Suppl 1):I81-4. · 15.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transmyocardial laser revascularization (TMR) provides relief for patients with chronic angina, nonamenable to direct coronary revascularization. Unmanageable, unstable angina (UUA) defines a subset of patients with refractory angina who are at high risk for myocardial infarction and death. Patients were classified in the UUA group when they had been admitted to the critical care unit with unstable angina for 7 days with three failed attempts at weaning them off intravenous antianginal medications. Seventy-six treated patients were analyzed to determine if TMR is a viable option for patients with unmanageable unstable angina. These patients were compared with 91 routine protocol patients (protocol group [PG]) undergoing TMR for chronic angina not amenable to standard revascularization. The procedure was performed through a left thoracotomy without cardiopulmonary bypass. These patients were followed for 12 months after the TMR procedure. Both unmanageable and chronic angina patients had a high incidence of at least one prior surgical revascularization (87% and 91%, respectively). Perioperative mortality (< or = 30 days post-TMR) was higher in the UUAG versus PG (16% vs 3%, p = 0.005). Late mortality, up to 1 year of follow-up, was similar (13% vs 11%, UUAG vs PG; p = 0.83). A majority of the adverse events in the UUAG occurred within the first 3 months post-TMR, and patients surviving this interval did well, with reduced angina of at least two classes occurring in 69%, 82%, and 82% of patients at 3, 6, and 12 months, respectively. The percent improvement in angina class from baseline was statistically significant at 3, 6, and 12 months. A comparable improvement in angina was found in the protocol group of patients. TMR carried a significantly higher risk in unmanageable, unstable angina than in patients with chronic angina. In the later follow-up intervals, however, both groups demonstrated similar and persistent improvement in their angina up to 12 months after the procedure. TMR may be considered in the therapy of patients with unmanageable, unstable angina who otherwise have no recourse to effective therapy in the control of their disabling angina.
    The Annals of Thoracic Surgery 10/1999; 68(4):1203-9. · 3.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transmyocardial laser revascularization was used as the sole therapy for patients with ischemic heart disease not amenable to percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. This technique uses a carbon dioxide laser to create transmyocardial channels for direct perfusion of the ischemic heart. Since 1992, 200 patients, at eight hospitals in the United States, have undergone transmyocardial laser revascularization. The patients have a combined 1560 months of follow-up for an average of 10 +/- 3 months per patient. Their age was 63 +/- 10 years and their ejection fraction was 47% +/- 12%. Eighty-two percent had at least one previous bypass graft operation and 38% had a prior angioplasty. Preoperatively, the patients underwent nuclear single photon emission computed tomography perfusion scans to identify the extent and severity of their ischemia. These scans were repeated at 3, 6, and 12 months. Angina class, admissions for angina, and medications were recorded. The perioperative mortality was 9%. Angina class decreased significantly from before treatment to 3, 6, and 12 months (p < 0.001). Likewise, there was a significant decrease in the number of perfusion defects in the treated left ventricular free wall. Concomitantly, there was a significant decrease in the number of admissions for angina in the year after the procedure when compared with the year before treatment (2.5 vs 0.5 admissions per patient-year). These combined results indicate that transmyocardial laser revascularization provides angina relief, decreases hospital admissions, and improves perfusion in patients with severe coronary artery disease.
    Journal of Thoracic and Cardiovascular Surgery 05/1997; 113(4):645-53; discussion 653-4. · 3.53 Impact Factor