Biomedical subjects

R Landreneau

Publications and source records attributed to R Landreneau.

24 records · Page 2Linked to original sources

PubMed1993

Video-assisted thoracoscopic wedge resection of T1 lung cancer in high-risk patients.

OBJECTIVE: This study assessed the reliability and safety of VATR for treatment of peripheral T1 lung cancer in high-risk patients. SUMMARY BACKGROUND DATA: Surgical resection is the best therapy for stage I lung cancer. Patients with poor cardiopulmonary status or those who are elderly (> 75 years of age) are considered to be at high risk from thoracotomy and are frequently referred for radiation therapy or expectant palliative management. Data from previous studies suggest that survival with wedge resection is similar to that with lobectomy. The authors propose VATR, which is minimally invasive, as a therapeutic option in patients considered to be at high risk for resection by thoracotomy. METHODS: Between November 1990 and November 1992, more than 400 thoracoscopic lung resections were performed. Thirty patients with poor pulmonary function (forced expiratory volume FEV1] < 1 L or < 35% predicted; arterial oxygen tension [PaO2] < 60 mmHg on room air; diffusion capacity [DCO] < 40%) underwent 31 VATRs (1 patient had a staged procedure for bilateral synchronous lung cancers). All patients had T1 peripheral lesions with no bronchoscopically visible lesions. Computed tomography of the chest revealed no evidence of mediastinal disease in all patients. RESULTS: Patients had a mean FEV1 value of 0.9 L (38% predicted) and a mean age of 71 years. Tumors were located in left upper lobe (LUL) in 13 patients, in right lower lobe (RLL) in 7 patients, in right upper lobe (RUL) in 6 patients, in left lower lobe (LLL) in 4 patients, and in right middle lobe (RML) in 1 patient. Computed tomography-guided wire localization, methylene blue surface injection, and intraoperative ultrasonography were used to assist in defining difficult lesions. All lesions were successfully resected without converting to thoracotomy. One patient died on the 34th postoperative day of myocardial infarction (operative mortality rate of 3%). Five patients had prolonged air leaks (< 5 days), with a median chest tube time of 3 days. Two patients experienced pneumonia. CONCLUSION: The authors concluded that VATR is a safe and reliable procedure for treatment of peripheral T1 lung cancer in high-risk patients. Long-term follow-up will be required to determine the efficacy of this procedure regarding survival and locoregional recurrence.

Aged↗

PubMed1991

Direct CO2 laser "revascularization" of the myocardium.

Evidence of regional myocardial perfusion and contractile function after direct CO2 laser myocardial revascularization (DLR) is lacking. We examined myocardial segment shortening, adenine nucleotide concentrations, and regional blood flow after DLR of the left anterior descending coronary artery (LAD) distribution before and after its proximal ligation in seven anesthetized conditioned dogs. Sonomicrometry assessed myocardial fiber shortening and radioactive microspheres were used to estimate baseline regional blood flows. Cardiopulmonary bypass was followed by cardioplegia arrest. Laser channels (1 mm diameter) were made every 3 to 5 mm in the LAD region with an 80 watt Laser-sonics CO2 unit. Bypass was terminated, the LAD occluded, and parameters reassessed. Core samples of myocardium from the lased LAD and control circumflex area were taken to assess adenine nucleotides. After occlusion, LAD distribution blood flow and myocardial shortening were reduced to pre-lasting ischemic controls. Adenine nucleotides were reduced in the LAD region relative to the control CMX area. DLR cannot be relied upon to acutely revascularize the ischemic myocardium.

Acidosis↗

PubMed1985

Cardiac response to fluid resuscitation from hemorrhagic shock.

The choice of fluid for volume replacement in hemorrhagic shock remains controversial. This study was done to compare the cardiac hemodynamic and metabolic effects of several regimens of fluid resuscitation. Thirty nonsplenectomized dogs subjected to two hours of hemorrhagic shock were resuscitated with shed blood alone or in combination with plasma, saline solution or Ringer's lactate solution. All regimens of volume replacement were equally effective in the initial resuscitation from severe shock. Furthermore, correction of metabolic acidosis and decreased lactate production were comparable in all groups. During late resuscitation (180 to 200 minutes), cardiac hemodynamic and myocardial efficiency were significantly lower in the shed blood, plasma and saline solution groups. Our data show that Ringer's lactate solution is singularly effective in maintaining left ventricular performance despite similar preload, coronary blood flow and myocardial oxygen delivery after all regimens of volume replacement.

Animals↗

PubMedDate not supplied

Prognosis of hospital survivors after salvage from cardiopulmonary bypass with centrifugal cardiac assist.

Since October 1986, 6 hospital survivors who were salvaged from cardiopulmonary bypass (CPB) with the Sarns centrifugal pump were observed. Centrifugal assist was employed only after failure to wean with usual resuscitative measures, including multiple high dose inotropes and intraaortic balloon pumping. There were five men and one woman, 46-59 years of age (mean 61 years). All patients had undergone coronary artery bypass grafting, with two patients having had concomitant left ventricular aneurysmectomy and two aortic valve replacement. Five patients had left ventricular assist only and one had biventricular assist. Duration of assist ranged from 26 to 72 hr (mean 48 hr). Complications were ubiquitous, and the resultant prolonged hospitalization was resource intensive. All hospital survivors remain alive and are in New York Heart Association functional Class II, with an average follow-up of 24 months, (6-41 months). Compared with preoperative values, current left ventricular function is improved in 2 patients, has deteriorated in 3, and is unchanged in 1. Thus, the Sarns centrifugal pump will allow salvage of some patients who otherwise are not weanable from CPB. Survivors can expect a reasonable functional capacity as reflected by this experience.

Aged↗

PubMedDate not supplied

Thoracoscopic approach for the pericardium.

The technique of video-assisted thoracic surgery (VATS) offers a new approach for management of effusive diseases of the pericardium. By the thoracoscopic approach, which can be performed through either the right or left chest cavity, an extensive pericardiectomy equivalent to one performed through a thoracotomy can be performed. Patients with benign effusive pericarditis, malignant pericardial effusions with a good prognosis, post-radiation pericarditis, purulent pericarditis, and delayed tamponade after open cardiac procedures can be optimally managed by video-assisted techniques.

Equipment Design↗

PubMedDate not supplied

Thoracoscopic instruments and ancillary equipment.

Thoracoscopic instruments of today are rooted in surgical innovations which began over 100 years ago. The advent of modern video-optical equipment and endoscopic techniques has given birth to a wide array of new instruments and surgical uses. This process is still in full swing. An overview of the most important developments is given, and future lines of development are explored.

Equipment Design↗