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Biomedical subjects

B Kiaii

Publications and source records attributed to B Kiaii.

10 recordsLinked to original sources
PubMed2006

Early outcomes of coronary artery bypass with and without cardiopulmonary bypass in octogenarians.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) surgery has been successfully used in diverse patient populations and has been postulated to be safer than conventional coronary artery bypass (CCAB) surgery in some high-risk patients, including the elderly. OBJECTIVE: To compare the safety of OPCAB surgery versus CCAB surgery in the octogenarian population of two large southwestern Ontario cardiac surgical units. RESULTS: Two hundred thirty-six consecutive octogenarians underwent primary isolated coronary artery bypass surgery from November 2000 to March 2005. Patients undergoing OPCAB surgery tended to have higher Parsonnet scores, while patients undergoing CCAB surgery had a greater number of emergent operations. The Canadian Cardiovascular Network predicted that mortality risk was similar in both groups. In-hospital mortality was similar between groups, as was postoperative myocardial infarction and new onset of renal dysfunction. However, in the OPCAB group, there was a decreased incidence of postoperative neurological dysfunction (2.3% in the OPCAB group versus 10.5% in the CCAB group, P=0.01), in particular cerebrovascular accidents (1.5% in the OPCAB group versus 7.6% in the CCAB group, P=0.05), and a decreased incidence of prolonged intubation (5.3% in the OPCAB group versus 13.3% in the CCAB group, P=0.04). Multivariable analysis found that cardiopulmonary bypass had no significant impact on mortality or length of stay. CONCLUSIONS: In octogenarian patients, OPCAB surgery is as safe as CCAB surgery in terms of mortality and major morbidity. Furthermore, a significant reduction in neurological dysfunction and prolonged intubation was seen in the OPCAB group compared with the CCAB group.

Aged, 80 and over↗
PubMed2003

Epicardial treatment of atrial fibrillation using cryoablation in an acute off-pump sheep model.

BACKGROUND: The purpose of this study was to test the feasibility and effectiveness of cryoablation therapy (SurgiFrost trade mark CryoCath, Endocare Inc., Irvine, California, USA) for linear epicardial treatment of atrial fibrillation in an acute off-pump sheep model. METHODS: After thoracotomy, we performed epicardial cryoablation (2 min intervals at -160 degrees C) with pacing electrodes positioned at the left atrial appendage (LAA), the pulmonary veins (PVs), the right atrial appendage (RAA), and the vena cava cranialis (VCC) in 8 sheep. Circular epicardial ablations were performed with online temperature measurement in the ascending aorta and in the esophagus. The sheep were sacrificed two hours after ablation procedure, and heart, lungs, and esophagus were retrieved for histological examination. Out of all 8 sheep, histo-pathological analysis was performed on the RAA and VCC in 6 sheep and on the CAA and PV in all 8 sheep. RESULTS: Thin-walled structures such as PVs and VCC showed electrical isolation. No significant changes in temperature in the descending aorta and the esophagus were observed. There was evidence of extensive transmural alteration including vascular lesions, myocardial degeneration and necrosis as well as epi- and endocardial necrosis in the left atria in three of 8 cases, in the right atria in 5 of 6 cases, in the VCC in 6 of 6 cases, and in the PV in 5 of 8 cases. Mild lesions of the muscular layer of the esophagus were found in 7 of 8 cases. CONCLUSIONS: Epicardial cryoablation is not effective on thicker tissues like LAA and RAA due to the rewarming of the current blood flow. However, thin tissues like VCC and PV can be isolated. Further chronic studies are necessary to evaluate the potential for regeneration of adjacent structures.

Animals↗
PubMed2001

RAVECAB: improving outcome in off-pump minimal access surgery with robotic assistance and video enhancement.

OBJECTIVE: To determine the efficacy of using the harmonic scalpel and robotic assistance to facilitate thoracoscopic harvest of the internal thoracic artery (ITA). DESIGN: A case series. SETTING: London Health Sciences Centre, University of Western Ontario, London, Ont. PATIENTS AND METHODS: Fifteen consecutive patients requiring harvest of the ITA for coronary artery bypass grafting. INTERVENTION: Robot-assisted, video-enhanced coronary artery bypass (RAVECAB) through limited-access incisions, using the harmonic scalpel and a voice-activated robotic assistant. MAIN OUTCOME MEASURES: Ease and duration of the harvesting technique, complications of the procedure, graft flow and patency, and duration of postoperative hospitalization. RESULTS: RAVECAB facilitated thoracoscopic dissection of the ITA with the harmonic scalpel in all cases. There were no conversions to a standard approach and no reoperations for bleeding. The mean (and standard deviation) ITA harvest time was 64.1 (22.9) minutes (range from 40 to 118 minutes). Robotic voice command capture rate was greater than 95%. Mean (and SD) intraoperative graft flows were 33.1 (26.8) mL/min (range from 14 to 126 mL/min). There was 100% graft patency on postoperative angiography. There were no deaths, perioperaive myocardial infarction or arrhythmias. Mean (and SD) postoperative hospitalization was 3.3 (0.8) days. CONCLUSIONS: RAVECAB is a demanding procedure that addresses many of the disadvantages of the "conventional" minimally invasive coronary artery bypass. It allows complete pedicle dissection with minimal ITA manipulation and assures sufficient conduit length and a tension-free coronary artery anastomosis. All anastomoses were performed under direct vision through a 5- to 8-cm inferior mammary incision.

Coronary Artery Bypass↗
PubMed2001

[Clinical experience in thoracoscopic left internal mammary artery harvesting with voice activated robotic assistance].

Between September 1998 to February 2000, 45 consecutive patients underwent robotic-assisted, video-enhanced coronary artery bypass grafting. All IMA's were harvested using the voice-activated robotic assistant (AESOP 3000, Computer Motion Inc, Santa Barbara, CA) and the Harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH). Left IMA's were successfully harvested in all patients. Harvested IMA's were anastomosed to LAD's under direct vision through limited left anterior thoracotomy. The IMA harvest time was 57.8 +/- 23.2 min, intraoperative graft flow was 34.3 +/- 20.5 ml/min, postoperative hospital stay was 3.9 +/- 1.5 days. The early postoperative angiogram showed that all grafts were patent. There was no mortality, no significant morbidity. The robotic assisted, video enhanced CABG provides safe and complete LIMA dissection with minimal manipulation and assures sufficient LITA length for tension free anastomosis.

Adult↗
PubMed2001

An alternative arterial conduit for totally endoscopic multivessel coronary artery bypass.

BACKGROUND: The ultimate goal of coronary artery bypass grafting (CABG) is the performance of a totally endoscopic procedure using multiple arterial conduits. At our center we have been routinely performing endoscopic robotic harvesting of internal thoracic arteries (ITAs) for use in minimally invasive CABG. The right gastroepiploic artery (RGEA) has been shown to be a reliable and versatile arterial conduit for bypass to coronary vessels not easily accessible by an ITA. The RGEA has already been harvested less invasively through a small laparotomy. This procedure could be made even less invasive by harvesting the RGEA laparoscopically, but this procedure has not yet been reported. The purpose of this study was to develop an endoscopic technique for harvesting the RGEA and demonstrate the safety and efficacy of this less invasive approach. METHODS: Twenty Duroc X Hampshire swine were administered general anesthesia and intubated. Ten mm and 5 mm trocars were then inserted. A 10 mm, 30-degree endoscope was adapted to a voice-activated robotic arm (AESOP), and the RGEA was harvested totally endoscopically using 5 mm harmonic scalpel shears. Intraoperative events and RGEA harvest times were recorded, and RGEA flows were measured after harvest. RGEA was delivered into the pericardial sac endoscopically. RESULTS: All RGEAs were successfully harvested without injury. Harvest time averaged 29.9+/- 10.9 min. The harvested conduits averaged 24.7+/- 2.37 cm in length. Flows were excellent in all harvested conduits, averaging 81.1+/- 31.8 cc/min. The harmonic scalpel controlled all RGEA branches with excellent hemostasis. CONCLUSION: The RGEA can be harvested safely through port access with robotic assistance. This conduit is of sufficient length to be used as an alternative arterial conduit for totally endoscopic multivessel coronary artery bypass.

Animals↗
PubMed2000

A comparison of robot-assisted versus manually constructed endoscopic coronary anastomosis.

BACKGROUND: New technology has enabled surgeons to attempt totally endoscopic coronary artery bypass grafting. Our purpose was to compare three different techniques of totally endoscopic anastomosis using a porcine animal model. METHODS: Porcine hearts were excised and the right coronary artery was dissected free for use as an arterial graft. The hearts were placed in a human thoracic model and an endoscopic arterial anastomosis between the free right coronary artery and the left anterior descending coronary artery was performed using one of the following: (1) two-dimensional visualization with straight endoscopic instruments (n = 8); (2) three-dimensional head-mounted visualization with curved endoscopic instruments (n = 7); or (3) three-dimensional visualization with robotic telemanipulation (n = 8). Pathologic analysis of suture placement, vessel trauma, and patency was performed. Anastomoses were graded according to quality, ease, and patency using a seven-point Likert scale (1 = excellent, 7 = very poor). RESULTS: Endoscopic anastomotic ease and quality were significantly improved when three-dimensional visualization and curved endoscopic instruments were employed. Telemanipulation enhanced the process and provided the best operative results with regard to time required to construct the anastomosis, as well as ease and quality. CONCLUSIONS: Totally endoscopic anastomosis is feasible using currently available technology. Three-dimensional visualization and robotic telemanipulation significantly facilitate anastomosis construction and will likely benefit clinical operative outcome.

Anastomosis, Surgical↗
PubMed2000

Robot-assisted computer enhanced closed-chest coronary surgery: preliminary experience using a Harmonic Scalpel and ZEUS.

BACKGROUND: Successful endoscopic harvesting of arterial conduits is critical to the performance of totally endoscopic bypass grafting. Recent success with computer-enhanced robotic systems in the performance of endoscopic single vessel coronary artery bypass (ENDOCAB) has paved the way for developing techniques for multivessel ENDOCAB. The Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH) has previously demonstrated versatility and efficacy in manual endoscopic internal thoracic artery (ITA) harvesting. This study was undertaken to determine the feasibility of adapting this technology to a robotic telemanipulation system and its safety and efficacy in telerobotic ITA harvesting. METHODS: The Harmonic Scalpel was adapted to the ZEUS robotic surgical system (Computer Motion, Goleta, CA) and used to harvest the ITA in 19 patients undergoing multivessel off-pump coronary artery bypass (OPCAB) surgery. With the left lung collapsed, the ITA was harvested in all patients with CO2 insufflation through three 5 mm ports in the left chest. Postoperative angiography and transthoracic Doppler studies were performed in all patients. RESULTS: There were no ITA injuries and patients tolerated insufflation without hemodynamic compromise. Side branches were controlled easily without bleeding. Average ITA harvest time was 65 +/- 21 minutes. All vessels were patent after harvesting and demonstrated no angiographic evidence of injury. CONCLUSIONS: This paper demonstrates a technique by which the Harmonic Scalpel can be readily adapted to the ZEUS robotic telemanipulation system. Using this system, ITA's can be safely harvested totally endoscopically within a reasonable time frame for patients undergoing ENDOCAB.

Coronary Angiography↗
PubMed1998

The basis for progesterone impairment of gallbladder contractility in male guinea pigs in vitro.

Progesterone suppresses gallbladder smooth muscle function but its exact mechanism is unknown. We sought to determine the cellular site where progesterone impairs gallbladder smooth muscle. Sixty-four adult male guinea pigs were injected with either progesterone (2 mg/kg/day sc) or normal saline (controls) for 7 days. Dose-response curves of gallbladder strips to cholecystokinin (CCK), bethanechol, and potassium (K+) were constructed in vitro. To better define the basis for the progesterone effect, gallbladder contractile response was determined to specific agonists: aluminum fluoride and mastoparan (direct G-protein activators), cyclopiazonic acid (CPA), and a calcium ionophore (A-23187). Gallbladder from animals on progesterone exhibited a marked decrease in contractile response to CCK and bethanechol compared with controls (P < 0.05). Further, gallbladder contraction remained depressed (P < 0.05) in progesterone-treated animals, when the G protein was directly activated with aluminum fluoride and mastoparan. In contrast, the responses to K+ (acting independent of receptor G-protein) and to A-23187 and CPA (agonists that bypassed the membrane) were comparable in both groups (NS). It is concluded that progesterone directly inhibits gallbladder smooth muscle contractility in vitro to a standard hormone, CCK, and a cholinergic agent. Such depressed contraction is not due to an altered contractile machinery, since it is normal with agonists that act independently of G-protein activation. Progesterone thus interferes with signaling through the G-protein, either by directly becoming closely associated with the cell membrane or by indirectly perturbing its receptor products.

Animals↗