Biomedical subjects

M J Mack

Publications and source records attributed to M J Mack.

At least 37 records · Page 2Linked to original sources

PubMed2000

Lung cancer. Surgical approaches and incisions.

With the emphasis of current surgical practice being increasingly focused on reducing the invasiveness of procedures, new techniques and concepts are changing the approach to thoracic surgery. Robotics offers the benefits of scaled motion, tremor filtration, and remote telemanipulation. It may be theoretically possible to introduce the concept of telementoring into thoracic surgery. By coupling two consoles, it would be possible for a senior surgeon to guide a junior surgeon through an endoscopic procedure in which the clinicians were in different locations. The use of telepresence surgery would also enable surgeons to perform or assist in operations taking place in remote locations. Robotics has the potential to increase the applicability of endoscopic surgery to an increasing number of patients with technically complex thoracic problems. Given that this technology is in its infancy, it remains too early in the process to determine if robotics will be a significant "value-added" element of cardiothoracic surgery; however, the possibilities continue to be limited only by imagination and ingenuity.

Forecasting↗

PubMed1999

Multivessel coronary bypass grafting without cardiopulmonary support.

Coronary artery bypass grafting without the aid of cardiopulmonary bypass (CPB) continues to gain popularity as an alternative to standard techniques of revascularization. CPB with cardioplegic arrest is associated with complications that may negate an otherwise technically flawless procedure. Experience has identified aspects crucial to the success of off-pump bypass grafting, such as patient selection, anesthetic and operative technique, and grafting sequence. We review recent technical advances and reported results for multivessel bypass grafting without CPB.

Anesthesia↗

PubMed1999

Results of graft patency by immediate angiography in minimally invasive coronary artery surgery.

BACKGROUND: Although minimally invasive direct coronary artery bypass (MIDCAB) is being employed for revascularization of the left anterior descending coronary artery (LAD) with the left internal mammary artery (LIMA), little objective data exist regarding graft patency. Because the procedure is performed on a beating heart through a limited access approach, concerns have been raised regarding the ability to perform as accurate an anastomosis compared with conventional coronary artery bypass (CAB). METHODS: A prospective study of consecutive patients undergoing MIDCAB LIMA to LAD was undertaken. All procedures were performed through a limited anterior thoracotomy incision with a stabilization device. Selective angiography of the LIMA graft was performed intraoperatively or in the immediate postoperative period. RESULTS: One hundred and three patients underwent the MICAB procedure. Angiographic evaluation of the anastomosis was obtained in 100 patients (97%). Angiographic graft patency was 99%, with perfect graft patency (no stenosis greater than 50%) being 91%. Three grafts were revised in the operating room. One patient underwent reoperation and 3 more underwent percutaneous transluminal coronary angioplasty. There were two noncardiac mortalities (1.9%), both with patent grafts. CONCLUSIONS: Immediate graft patency after MIDCAB is acceptable, and comparable with conventional CAB data, although meaningful comparison is difficult. The significance of early angiographic findings and the role for early angiography remain to be defined.

Adult↗

PubMed1999

Video-assisted surgical management of achalasia of the esophagus.

PURPOSE: Video-assisted surgical approaches to esophageal achalasia continue to be explored by many surgeons involved in the management of this motor disorder. We report our experience with thoracoscopic and laparoscopic esophagomyotomy to more clearly define the efficacy and safety of these approaches. PATIENTS: Over 73 months, 58 patients with achalasia underwent thoracoscopic myotomy (n = 19) alone or laparoscopic myotomy (n = 39) with partial fundoplication (anterior = 15; posterior = 24). Mean age was 47.2 years and average length of symptoms was 60 months. Primary symptoms were as follows: dysphagia, 100%; pulmonary abnormalities, 22%; weight loss; 47%, and pain, 45%. Mean esophageal diameter was 6 cm and tortuosity was present in 16% (9/58) of patients. Prior management consisted of dilation (n = 47), botulinum toxin injection (n = 8), and prior myotomy (n = 1). METHODS: In the operating room all patients underwent endoscopic examination and evacuation of retained esophageal contents. The esophagomyotomy was extended 4 cm superiorly and inferiorly to 1 cm beyond the lower esophageal sphincter. Thoracoscopic and laparoscopic procedures were completed in all patients without conversion to an open operation. Mean operative time was 183 minutes (+/-58.1) and hospital stay averaged 2.3 days (+/-0.8). There was no operative mortality. The 1 operative complication was a perforation that was identified during the operation and repaired thoracoscopically. RESULTS: Symptoms improved in 97% of patients. Mean dysphagia scores (range 0-10) decreased from 9.8 +/- 1.6 before the operation to 2.0 +/- 1.5 after the operation (P <.001) at a mean follow-up of 6 months. Postoperative reflux symptoms developed in 5% (1/19) of the thoracoscopy group and 8% (4/39) of the laparoscopy group. Nine patients have persistent or recurrent dysphagia (16%). Seven patients have successfully undergone Savary dilation, and 2 required esophagectomy to manage recalcitrant dysphagia. CONCLUSION: At this intermediate term analysis, video-assisted approaches for management of achalasia are a reasonable alternative to extended medical therapy or open operations.

Deglutition Disorders↗

PubMed1999

Is there a future for minimally invasive cardiac surgery?

Although cardiac surgery has made significant contributions to the cardiac health of millions of patients over the past 40 years, it has evolved from an 'emerging growth' to a 'mature' industry. Along with this maturation has come an 'inertia of success' and lack of innovation. Minimally invasive cardiac surgery is an attempt to develop more patient friendly cardiac procedures yet maintain the superior long term results of conventional cardiac surgery. A broad spectrum of new surgical techniques and technical innovations has been fostered. The impact has been not only that of 'discontinuous innovation' of a new type of cardiac surgery but also a significant 'coat-tail' effect of 'upgrading' conventional cardiac surgery. It is difficult to adapt to change. But if we maintain an open-mindedness toward evolution with a firm foundation in proven standards, our patients will be the beneficiaries.

Coronary Artery Bypass↗

PubMed1998

Computer-assisted telemanipulation: an enabling technology for endoscopic coronary artery bypass.

BACKGROUND: The ultimate objective of minimally invasive coronary artery bypass grafting is to perform the anastomosis totally endoscopically. In this feasibility study, we examined the potential of performing coronary artery bypass grafting with the use of computer-assisted telemanipulation technology. METHODS: Intuitive Telemanipulation Technology (Intuitive Surgical, Mountain View, CA) was used to perform an arterial graft to left anterior descending coronary artery anastomosis in an ex vivo on-bench swine heart model. The degree of difficulty in performing the anastomosis, intraoperative events, duration of the anastomosis, and its quality were determined. RESULTS: Anastomosis was performed with relative facility, in a range of 10.7 to 17.4 minutes (mean +/- standard deviation, 14.6 +/- 2.6 minutes). All anastomoses were patent and of good quality except one, which had 30% narrowing of its heel. CONCLUSIONS: We conclude that Intuitive Telemanipulation Technology may in the future permit the performance of quality totally endoscopic coronary artery anastomosis with facility and acceptable time.

Anastomosis, Surgical↗

PubMed1998

Arterial graft patency in coronary artery bypass grafting: what do we really know?

BACKGROUND: With increasing use of beating heart techniques for bypass of the left anterior descending coronary artery with the left internal mammary artery (LIMA), appropriate concerns have been raised of whether graft patency by these techniques compares favorably with conventional, arrested heart techniques. METHODS: All published articles that examine outcome efficacy of the LIMA graft to the left anterior descending coronary artery were reviewed. Because angiography has been considered the "gold standard," only those studies that included angiographic follow-up were analyzed. RESULTS: From 1972 through 1998, there have been 37 peer-reviewed publications that examined outcomes of LIMA grafting in conventional coronary bypass grafting, of which 27 contained angiographic follow-up data. The completeness of angiographic follow-up was variable, but early graft patency (< or =1 month) in studied patients ranged between 94% and 99%. Late graft patency (up to 15 years) ranged from 51% to 98%. Five recent series of minimally invasive direct coronary artery bypass grafting that contained LIMA graft patency data show early graft patency rates between 91% and 99%. CONCLUSIONS: Meaningful comparison of LIMA graft patency between arrested heart, conventional coronary artery bypass grafting, and minimally invasive direct coronary artery bypass grafting is difficult; however, early graft patency by both techniques can confidently be stated as being 90% or greater.

Coronary Angiography↗

PubMed1998

Early chest tube removal after video-assisted thoracoscopic wedge resection of the lung.

BACKGROUND: Traditional management of chest tubes after a wedge resection of peripheral pulmonary tissue often lasts several days. We evaluated the safety and efficacy of early chest tube removal in the recovery room after uncomplicated video-assisted thoracoscopic surgical wedge resections of the lung. METHODS: From December 1995 to July 1997, 59 patients underwent video-assisted thoracoscopic surgical wedge resection for indeterminate pulmonary nodules (n = 33) or interstitial lung disease (n = 26). We prospectively evaluated early chest tube removal in the last 33 patients; 18 patients with nodules and 15 with interstitial lung disease. Patients who were in the early removal group had chest tubes removed within 90 minutes of the surgical procedure. Criteria for early removal were established and met before chest tube removal. There was no difference between groups with respect to age, sex, comorbidities, or pathologic evaluation of resection specimens. RESULTS: Ninety-four percent (31 of 33) of patients considered for early chest tube removal met criteria for immediate tube removal. Air leak and excessive drainage prohibited early removal in 2 patients. Patients who were managed traditionally averaged 3.3 days with chest tubes--1.8 days on suction, 1.3 days on water seal. Patients who had early removal of their chest tubes had a shorter postoperative stay (2.0+/-1.0 versus 3.9+/-2.1 days, p = 0.001) and fewer chest roentgenograms (2.8+/-2.1 versus 5.1+/-2.0, p = 0.001). There were no differences in complications including small pneumothoraces (5 in the early removal group, 7 in the traditional management group), which were managed with observation alone. Total narcotic requirements were greater in the traditional management group (54+/-44.8 versus 24.6+/-22.9 morphine milligram equivalents, p = 0.005). CONCLUSIONS: Early chest tube removal after video-assisted thoracoscopic surgical wedge resection of peripheral pulmonary tissue appears to be a safe and cost-effective practice if strict criteria for removal are met.

Adult↗

PubMed1998

Thoracoscopic sympathectomy: the U.S. experience.

OBJECTIVE: 48 patients underwent TSSYM. Charts of patients undergoing thoracoscopy were reviewed to assess the safety and efficacy of thoracoscopic sympathectomy (TSSYM). DESIGN: A retrospective review was undertaken at four United States medical centers. RESULTS: TSSYM was performed for reflex sympathetic dystrophy in 27 patients, hyperhydrosis palmaris in 15 patients, and Raynaud's upper extremity ischemia and splanchnic pain in 2 patients each. Anesthesia with one lung ventilation was used. 2.9 ports were used per patient and 0.8 chest tubes were placed per patient. All patients underwent resection of the sympathetic chain, usually with a clip along the bottom of the resected chain. Laser, electro-ablation and electroresection were not used by any of the surgeons in his series. The mean length of hospital stay was 1.8 days. CONCLUSIONS: TSSYM is a safe and effective technique for treatment of a variety of thoracic disorders.

Endoscopy↗

PubMed1998

Minimally invasive direct coronary artery bypass: technical considerations and instrumentation.

Minimally invasive coronary artery bypass is defined as any maneuver or modification of conventional coronary bypass that decreases adverse effects. These adverse effects fall into three broad categories, which are access trauma, consequences of cardiopulmonary bypass, and aortic manipulation. In the minimally invasive direct coronary artery bypass (MIDCAB) approach, coronary revascularization is performed via a limited access incision, usually a left anterior thoracotomy, through which a left internal mammary artery is anastomosed under direct vision to the left anterior descending artery on a stabilized beating heart. Harvest of the left internal mammary artery can be performed with video assistance (two- or three-dimensional or under direct vision). A variety of offset chest wall retractors that allow internal mammary artery harvest under direct vision have simplified the procedure, and several mechanical stabilization devices (with or without suction) allow local wall immobilization for a target vessel anastomosis. Graft patency data from early series of stabilized MIDCAB procedures and published series of left internal mammary artery graft patency with conventional bypass grafting appear to be comparable. Current indications for MIDCAB include restenosis of the left anterior descending artery after catheter-based therapy and the necessity for target vessel revascularization in elderly high-risk patients with multivessel disease. Limitations of the MIDCAB procedure include mostly single vessel revascularization of the anterior aspect of the heart.

Aged↗

PubMed1998

The role of thoracoscopy in lung cancer management.

Video-assisted thoracic surgery (VATS) has enabled more complex procedures previously requiring thoracotomy to be accomplished in lung cancer management. VATS today can be employed in the evaluation of idiopathic (and known) malignant pleural effusions, mediastinal adenopathy, indeterminate pulmonary nodules, and compromise resection and lobectomy of peripheral stage I non-small cell lung cancer. Thus, VATS is becoming an accepted approach to a variety of intrathoracic problems, although its absolute indications for patients with lung cancer have yet to be firmly defined. This article reviews the authors' current experience with VATS procedures in the treatment of patients with lung cancer.

Endoscopy↗

PubMed1998

Video-assisted thoracoscopic excision of herniated thoracic disc: description of technique and preliminary experience in the first 29 cases.

This study evaluates the technique and results of video-assisted thoracoscopic surgery (VATS) for the treatment of symptomatic thoracic disc herniation. Results were compared with a literature review of open surgical techniques of thoracic disc excision with regard to efficacy, safety, and surgical outcomes. VATS has recently been described for thoracic surgery as having the advantage of decreased postoperative pain and morbidity, faster patient recovery, and shortened intensive care unit (ICU) hospitalization. Twenty-nine consecutive patients underwent VATS for symptomatic thoracic disc herniation. Herniations ranging from T5-6 to T12-L1 were successfully approached by using a three- or four-portal strategy. Postoperative magnetic resonance imaging (MRI) scans were evaluated. Pre- and postoperative Oswestry Disability Questionnaires and Linear Analog Pain Scale data were obtained. Patients were grouped according to presenting symptoms. The minimal follow-up was 1 year (range, 12-24 months). Mean operative time was 175 min for 29 patients. Significant improvement (p < 0.01, paired t test) was recorded in Oswestry Disability Questionnaires and Linear Analog Scale Tests. Of the patients, 75.8% (22) were satisfied, 3.4% (one) unsatisfied, with 20.1% (six) unchanged. Narcotic use was significantly eliminated or reduced. Mean return to work was 5 weeks (private insurance) and 21 weeks (workers compensation). The surgical and postoperative complication rate was 13.8%. VATS appears to be a safe and efficacious method of excising herniated thoracic discs. Follow-up results at 1 year resulted in high patient satisfaction. VATS advantages include decreased length of hospitalization as well as improved patient comfort.

Adult↗

PubMed1998

Adverse effects of medications commonly administered to thoracic surgical patients.

A wide variety of medications is commonly used following thoracic surgical procedures. All of these medications have associated side effects that may adversely affect the recovery of patients. A complete understanding of the important adverse effects of all the medications used postoperatively can limit or eliminate unwanted medication effects and lead to a more successful outcome. This article will review the important actions and side effects of the most commonly administered medications following thoracic surgical procedures.

Analgesics, Opioid↗

PubMed1998

Video-assisted thoracic surgery thymectomy for myasthenia gravis.

Video-assisted thoracic surgery thymectomy was employed in the management of myasthenia gravis in a series of 20 patients. As the technique evolved, the authors preferred a right-sided approach, and the technical details of the process are discussed. At a mean follow-up of 30 months, clinical results are comparable to published series of other approaches. It is hoped that the superior cosmesis associated with this less-invasive approach leads to earlier thymectomy in management of this disease.

Endoscopy↗

PubMed1998

Effect of minimally invasive thoracic surgical approaches on acute and chronic postoperative pain.

Acute postthoracotomy pain and chronic postthoracotomy pain are significant problems leading to increased length of hospital stay and medical costs, reduction in patient quality of life and patient productivity, and potential immunologic derangement that may compromise oncologic surgical results. Minimally invasive surgical approaches can potentially benefit the patient by reducing postoperative pain-related morbidity. Objective data supporting our inclination that these VATS approaches are superior to open thoracic surgical techniques is accumulating. Further study of the relative costs, risks, and benefits of standard postoperative analgesic management (e.g., epidural analgesia) combined with limited thoracotomy compared to VATS techniques is warranted as we try to define the most effective perioperative management of the patient requiring pulmonary resection.

Acute Disease↗

PubMed1997

Perspectives on minimally invasive coronary artery surgery. Current assessment and future directions.

Excellent long-term results have been obtained with conventional coronary artery bypass surgery. However, significant mortality and morbidity still exists due to the use of cardiopulmonary bypass for circulatory support and the traditional method of access by median sternotomy. Minimally invasive concepts have been adopted in cardiac surgery in an attempt to make these procedures less invasive. Minimally invasive alternatives include the minimally invasive direct coronary artery bypass procedure in which cardiopulmonary bypass is eliminated and the operation is performed through minimal access incisions; the Port Access approach in which the procedure is done through minimal access incisions and cardiopulmonary support is instituted through an extra thoracic approach. The third alternative is the "off pump" sternotomy approach which allows greater access for more extensive revascularization, but the procedure is still performed on a beating heart. All procedures have their limitations, but offer the potential for a less invasive approach for coronary revascularization. Current results are only short to immediate term, but are promising. Current efforts to extend the procedure include improved methods for facilitating beating heart coronary artery surgery, better visualization for endoscopic approaches and finding alternatives to cardiopulmonary bypass for circulatory support and alternatives to suturing for performance of vascular anastomoses. Additional alternatives to extend the procedure include hybrid operations in which minimally invasive coronary bypass is combined with transcatheter procedures (stents) for the treatment of multivessel disease.

Catheters, Indwelling↗

PubMed1997

Video-assisted thoracic surgery: has technology found its place?

BACKGROUND: Since the introduction of minimally invasive surgical techniques in thoracic surgery in 1990, video-assisted thoracic surgery (VATS) has become the approach for many thoracic operations. The role of VATS has slowly evolved but has not been clearly defined. To better understand the role of VATS, we undertook a survey of practicing thoracic surgeons. METHODS: A questionnaire was sent to members of the General Thoracic Surgery Club asking the role of VATS in their practice and their opinions regarding appropriate applications, advantages, and limitations of the approach. RESULTS: Two hundred of the 229 members (87.3%) responded to the questionnaire. In this largely academic (66.3%) group of thoracic surgeons, 72% of whom had more than 10 years experience in general thoracic surgery, VATS was the preferred approach (> 50% response) for the management of pleural disease, lung biopsy, recurrent pneumothorax, and sympathectomy. A majority of respondents thought that VATS was an acceptable approach for the diagnosis of the indeterminate pulmonary nodule and of anterior and posterior mediastinal masses, and for the management of early empyema, clotted hemothoraces, secondary pneumothorax, limited lung cancer treatment, and benign esophageal disease. Video-assisted thoracic surgery was thought to be unacceptable or investigational by a majority for thymectomy, lobectomy, and lung volume reduction operations. Video-assisted thoracic surgery still represents only a small portion of the thoracic procedures performed, but there is a gradual increase in its rate of use, although 38.1% expressed concern regarding overuse. The main limitation was thought to be in the management of oncologic disease. CONCLUSIONS: It appears that VATS is a valuable addition to the practice of thoracic surgery, but significant limitations exist. Although there appear to be many specific indications defined, there is still a significant evolutionary component.

Attitude of Health Personnel↗

PubMed1997

Video-assisted coronary bypass grafting on the beating heart.

BACKGROUND: Concepts to make coronary artery bypass operations less invasive include minimization of access incisions, elimination of cardiopulmonary bypass, and no manipulation of the aorta. A spectrum of minimally invasive coronary bypass procedures now exist that eliminate the median sternotomy (port-access approach), cardiopulmonary bypass ("off-pump bypass"), or both (minimally invasive direct coronary artery bypass procedure). Although all have advantages in decreasing the morbidity of myocardial revascularization, significant limitations exist including surgeon experience, access, exposure, visualization, hemodynamic support, and technique of anastomosis. METHODS: In an attempt to extend the applicability of the current minimally invasive techniques, efforts are being made both to extend the indications for the procedure as well as to modify the technical aspects. Our current experimental protocol involves a ports-only approach with three-dimensional video imaging, percutaneous Hemopump circulatory support, Octopus coronary immobilization, and an endoscopically sutured coronary anastomosis. RESULTS: In a series of animal studies we have been able to successfully accomplish a totally endoscopic coronary artery bypass procedure on a beating heart without cardiopulmonary bypass. CONCLUSIONS: Although endoscopic coronary artery bypass without cardiopulmonary bypass is possible, many technical challenges remain. Three-dimensional video imaging, wall motion immobilization and presentation, and an axial-flow device can facilitate the procedure. Future enabling technology including motion robotics and nonvisual imaging systems may ultimately further minimize the invasiveness of surgical myocardial revascularization.

Coronary Artery Bypass↗