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Biomedical subjects

G Maturana

Publications and source records attributed to G Maturana.

At least 19 recordsLinked to original sources
PubMed1995

[Papillary muscle rupture in myocardial infarction].

We report nine patients with acute mitral regurgitation secondary to post-infarction papillary rupture operated between 1980 and 1992. Seven cases had posterior papillary muscle rupture. All patients were in critical conditions with pulmonary edema at the moment of surgery. In eight cases, mitral valve replacement was performed (4 with mechanical prostheses) and in one, the valve was repaired with papillary muscle reimplantation. Six cases were also subjected to myocardial revascularization with sapheneous vein grafts. Two patients (22%) died during the postoperative period and 4 had postoperative complications. The seven survivors have been followed during 6 to 115 month. Of theses, one died six month after surgery due to congestive heart failure, three are in functional class I and the rest in functional class II. It is concluded that, although mitral valve replacement for papillary muscle rupture has a high operative mortality and morbidity, long term results are satisfactory.

Aged↗
PubMed1993

[Surgery of acute mitral valve insufficiency].

Between January 1980 and December 1990, 16 patients with acute mitral insufficiency were operated on an emergency basis at our institution. They represented 1.8% of all mitral surgical cases. All of them were in acute pulmonary edema and 7 in cardiogenic shock. The etiology was ischemic in 6, degenerative in 4, infectious in 3, degenerative and infectious in 2 and traumatic in 1. The pathologic mechanism was chordal rupture in 8 patients (5 anterior) and papillary muscle rupture in the other 8 (5 posterior). A mitral valve replacement was performed in all cases. Two patients died and 7 had morbidity in the postoperative period. One patient died 6 months after surgery of congestive heart failure. Ten patients are in NYHA functional class I at a mean follow-up of 48.1 months. Acute mitral insufficiency has different etiologies and pathologic mechanisms. In spite of the severe clinical condition of these patients, mitral valve replacement has good immediate and long-term results.

Acute Disease↗
PubMed1992

[Dissection of the ascending aorta (type A): diagnostic aspects, surgical treatment and long-term follow-up].

Aortic replacement is the treatment of choice and improves the natural history of dissections involving the ascending aorta. Forty patients (23 male), aged 49.4 years, have been operated at the hospital Clínico de la Universidad Católica. Twenty six presented with acute dissections. Angiography conformed the dissection in 63.3% and computed axial tomography in 84.6% of patients; lately, transesophageal echocardiography has become the most sensitive diagnostic method. Twenty three patients (57.5%) were subjected to emergency operations and 17 to semielective procedures. In 24 patients (60%) ascending aorta was replaced and in 16 a composite graft was used. Operative mortality was 27.5%. Univariate analysis showed that the period in which the operation was performed and the presence of limb ischemia were the only independent predictors of operative mortality. Long term follow up was achieved in 26 patients (89.6%). Actuarial 5 year survival without considering operative mortality was 87.9%. It is concluded that patients with acute dissections involving the ascending aorta should be operated as soon as the imaging diagnosis is complete and, since this is a palliative procedure, a close follow up is required for early detection of complications.

Adult↗
PubMed1992

[Radiotherapy in the treatment of non-small-cell lung cancer].

The results of curative radiotherapy in 59 patients with non-small-cell carcinoma of the lung treated from 1977 to 1988 are reported. Squamous cell carcinoma without evidence of metastatic disease was present in 28 patients. Radiotherapy alone was used in 43 patients; 13 patients received either pre or post operative radiotherapy. Complications developed in 6 patients, only 1 had esophageal stenosis deemed important. The first site of failure was extrathoracic in 76% of patients, the brain being the most frequently involved site (41%). Brain failure rate was greater for squamous cell carcinoma than for other tumors. The 5 year survival rate was 20% with a minimum follow up period of 24 months (median 57). Better results were obtained in patients receiving high dose continuous radiotherapy and in those with associated surgery. Thus, radiotherapy is an alternative therapy for patients with lung carcinoma, with a reasonable survival rate and few complications.

Actuarial Analysis↗
PubMed1992

[Interventricular rupture following myocardial infarction. Surgical treatment and long-term follow-up].

The natural course of post myocardial infarction ventricular septal defect is towards cardiogenic shock and death. 50% in the first week, over 90% a year latter. Between 1973-1989, 28 patients where operated on. Before surgery 14 patients (53%) where in Killip IV, 5 patients (19%) in III, 5 patients (19%) in II and 2 patients in I. The repair was accomplished under hypothermia and cardioplegia, with the insertion of a Teflon patch to close the defect in 20 patients (70%). Complementary procedures (CABG, Pacemaker, repair of dissections) were performed in 12 patients (47%). Three patients (10%) could not be weaned from the pump; another 10 (36%) died before discharge: 2 with multisystem failure and sepsis, the other 8 with cardiogenic shock (4 with residual VSD). The only independent predictor of operative mortality, by univariate analysis, was preoperatory cardiogenic shock. All 15 survivors (100%) where followed between 5 months and 14.5 years (mean 104.5 months). Two patients died at 4 years, one at 10, another at 10.5 years. The actuarial probability of being alive after discharge was 100% at 4 years, 75% at 5, and 50% at 10 years. At last follow up only 2 patients had mild dyspnea, the remaining where asymptomatic. Surgical treatment provides an opportunity to improve this otherwise dismal survival and offers a surprising good long term result. An early diagnosis and efficient repair, before the onset of cardiogenic shock, should provide better results.

Actuarial Analysis↗
PubMed1990

[Wolff-Parkinson-White syndrome: late results of surgical treatment].

We followed 25 patients operated on for Wolff-Parkinson-White syndrome between August 1985 and October 1989. Their mean age was 37 +/- 12 years and arrhythmia had been present for 5 to 30 years. A mean of 3.3 +/- 1.2 antiarrhythmic agents had failed in controlling recurrences. Tachycardia was orthodromic in 21 patients and antidromic in 1, while 3 patients presented rapid atrial fibrillation with hemodynamic deterioration. Drug refractoriness (n = 23) or intolerance (n = 2) were the main surgical indications. The location of accessory pathways was lateral in 19 patients, anteroseptal in 3, posteroseptal in 2, postero lateral in 1 and right lateral in 1 patient. One patient had a double pathway. There was no surgical mortality. After a follow-up period ranging from 1 to 50 months recurrence of arrhythmia was observed in one patient and electrophysiologic evaluation showed persistence of a left lateral pathway in another. The remaining 24 patients are free of symptoms at the end of follow up. Thus, surgical treatment is a curative therapy for most patients with WPW.

Adolescent↗
PubMed1990

[The long-term evolution of aortic valve replacement with a mechanical prosthesis: experience with the Starr-Edwards (1965-1974) and Bjork-Shiley (1973-1981) prostheses].

We compared the short- and long-term results of isolated aortic valve replacement in 98 patients receiving a Starr-Edwards (SE) prosthesis from 1965 to 1974 and 80 pts receiving a Bjork-Shiley (BS) prosthesis from 1973 to 1981 at our institution. Operative mortality was 20% (SE) and 6% (BS). Follow-up information was obtained in 88% (SE) and 96% (BS) of pts discharged alive. The mean period of follow up was 8.2 and 6.7 years respectively. The 5 and 10 year actuarial survival rates were 72% and 61% (SE) vs 89% and 83% (BS). Complications per 100 pt-years among pts with SE and those with BS were: systemic emboli 2.8 vs 0.6, major hemorrhagic events 1.25 vs 1.36, perivalvular leak 1.6 vs 1.15, endocarditis 0.31 vs. 0.39, prosthetic thrombosis 0 vs 0.58 and ball variance 0.47 vs 0, respectively. Some of these differences may reflect shortcomings of the initial surgical experience during the period in which the SE prosthesis was used, rather than different performance of both valves.

Adolescent↗
PubMed1989

[Surgery of evolving myocardial infarction].

Limitation of infarct size has been proven to improve the prognosis in patients with recent myocardial infarction (MI). Emergency coronary bypass surgery may be used for this aim. We operated on 44 such patients within 15 days of onset of MI. Operation was done within 6 hr in 11 patients and later on in the other 33, due to post infarction angina or incomplete MI. One patient died in the perioperative period. Thirty nine patients were followed at a mean of 33 months: 2 have angina, one dyspnea and the rest is asymptomatic. We believe that bypass surgery is an effective treatment in selected patients with recent MI.

Adult↗
PubMed1986

Disc dislodgment in Björk Shiley mitral valve prosthesis: two successfully operated cases.

Two patients with Björk Shiley mitral valve replacement had migration and embolization of the occluding disc. One patient suffered migration of the disc a few hours after surgery and the other had a strut fracture with disc translocation six years after the initial operation. Clinical signs in both cases were pulmonary edema, cardiogenic shock, and absence of prosthetic sounds. Both patients were reoperated on an emergency basis, recovering after a complicated postoperative course. They are on functional Class I, 8 and 1 years later, respectively, with their dislodged discs still in the abdominal aorta. The only hope for survival in these patients is emergency reoperation, once the prosthetic mitral valve dysfunction is confirmed.

Adult↗
PubMed1986

Ultrastructural myocardial preservation during coronary artery surgery: a controlled, prospective, randomized study in humans.

Potassium cardioplegia was compared with normothermic, intermittent ischemic arrest in 30 patients undergoing multiple coronary artery bypass grafts. Group 1 comprised 15 patients in whom cold potassium cardioplegia with St. Thomas' Hospital solution was used. In Group 2 were 15 patients who underwent intermittent ischemic arrest during the construction of the distal anastomoses. Two myocardial transmural left ventricular biopsies were done in each patient. There was no operative mortality. Electron microscopical examination showed normal myocardial ultrastructure in both groups. In particular, mitochondria were well preserved in all samples. The postoperative electrocardiogram demonstrated a new Q wave in 1 patient in Group 2 whose level of the myocardial isoenzyme of creatine phosphokinase (CPK-MB) was within the normal range. The peak CPK-MB release in Group 1 was 23.2 +/- 20.1 IU and in Group 2, 19.9 +/- 15.1 IU. This difference was not statistically significant. The mean period of anoxic arrest in Group 1 was 49.5 +/- 15 minutes and in Group 2, 25.5 +/- 8 minutes (p less than 0.001). Total cardiopulmonary bypass time in Group 1 was 114.5 +/- 20 minutes and in Group 2, 90.2 +/- 16 minutes (p less than 0.01). It is concluded that both techniques can preserve myocardial subcellular architecture during multiple coronary artery bypass grafting in patients with normal left ventricular function.

Bicarbonates↗
PubMed1985

Surgical removal of entrapped endocardial leads without using extracorporeal circulation.

Of 267 patients having a tined endocardial lead implanted from 1978 to December 1983, three (1.1%) developed pulse generator pocket infection. Proper treatment of this complication involves removal of the pulse generator, continued external pacing via the implanted lead, pocket drainage and administration of specific antibiotics until the infected area clears. In two patients, the electrode could not be removed by traction. A sternotomy was performed, the pericardium was opened, the endocardial electrode was located by palpation, and a purse string suture (PSS) was prepared around it on the right ventricular wall. A new myocardial electrode with its corresponding generator was then implanted to reestablish pacing. Through the PSS the myocardium was incised, the distal end of the endocardial lead was exteriorized and severed, and the PSS was tied. The remaining lead was withdrawn proximally and the surgical wounds were closed. The results of this procedure have been been excellent, allowing the removal of the entrapped leads, with continuous pacing and without the need for extracorporeal circulation.

Aged↗