The 600 Gram CO2 Absorption Canister: An Experimental Study

Model investigations were performed on a canister containing 600 g of Sodasorb indicator soda lime in a transparent lime compartment used in the Hafnia circle. The CO₂ input was 300 ml per min. Carbon dioxide will be efficiently eliminated from the gas mixture conveyed to the patient connection in this system for at least 4 h, irrespective of the rate of fresh gas flow. There was proportionality between the fresh gas inflow and the duration of effective CO₂ elimination. The relative efficacy of the CO₂ absorption was investigated at different levels in the canister. The temperature in the axis of the lime compartment was 43–52° C, and the temperature of the gas mixture conveyed to the patient attachment 30–35° C.
The colour shift in the lime charge was a reliable indicator of the efficiency of CO₂ elimination. The canister should be replaced when the colour shift has progressed to 2/3 of the lime charge.
The canister contains no disposable parts except for the lime charge. All the components of the circle system should be taken apart and cleaned after each anaesthesia.     

An Improved Technique for the Internal Mammary Artery Coronary Bypass Graft Procedure

An improved technique for internal mammary artery graft preparation is described. Following cautery dissection of the internal mammary artery (IMA) pedicle, the pedicle investing fascia is incised to the adventitial level along a single plane. This incision allows the tissue around the internal mammary artery to fall away and severs the muscular constrictions that often surround the internal mammary artery. Balloon calibration is performed to identify remaining constrictions and to relieve internal mammary artery spasm. A shear force limiting gauge insures that the exerted balloon force remains below the level demonstrated to cause intimal damage during electron microscopic studies. This technique allows full internal mammary artery distention without the devascularizing effects of full skeletonization. Distention of the distal internal mammary artery provides an enlarged hood to facilitate suture placement. Elongation of the internal mammary artery during balloon calibration aids in the performance of sequential grafts. This technique has been applied to 793 patients over the past five years. Postcalibration flow rates increased 3- to 18-fold over precalibration flow rates. Two early occlusions occurred during this series, one due to endothelial strippage prior to the development and use of the shear force limiting gauge. Follow-up showed 93.3% of patients to be asymptomatic. This combination of fascial incision and balloon calibration appears to offer safe technical and functional improvements to the performance of the internal mammary artery graft.     

Port-Access Bilateral Internal Mammary Artery Grafting for Left Main Coronary Artery Disease: Canine Feasibility Study

A bstract Background : To extend the applications of minimal access cardiac surgery, an endovascular cardiopulmonary bypass (CPB) system that allows cardioplegia delivery and cardiac venting was used to perform bilateral internal mammary artery (IMA) bypass grafting in six dogs. Methods : The left IMA (LIMA) was taken down thoracoscopically from three left lateral chest ports, followed by the right IMA (RIMA) from the right side. One left-sided port was extended medially 5 cm with or without rib resection, to expose the pericardium. Both IMAs were divided and exteriorized through the left anterior mediastinotomy. Flow and pedicle length were satisfactory in all cases. Femoral-femoral bypass was used and the heart arrested with antegrade delivery of cardioplegic solution via the central lumen of a balloon catheter inflated to occlude the ascending aorta. All anastomoses were made through the mediastinotomy under direct vision. In five studies the RIMA was attached to the left anterior descending artery (LAD) and the LIMA to the circumflex, and in one study the RIMA was tunneled through the transverse sinus to the circumflex and the LIMA was anastomosed to the LAD. All animals were weaned from CPB in sinus rhythm without inotropes. CPB duration was 108 ± 27 minutes (mean ± SD) and the clamp duration was 54 ± 10 minutes. Results : Preoperative and postoperative cardiac outputs were 2.9 ± 0.71/min and 2.4 ± 0.31/min, respectively (p = NS), and corresponding pulmonary artery occlusion pressures were 6 ± 3 mmHg and 7 ± 2 mmHg, respectively (p = NS). All 12 grafts were demonstrated to be fully patent. Postmortem examination revealed well aligned pedicles and correctly grafted target vessels. Conclusion : This canine model demonstrates the potential for a less invasive approach to the surgical management of left main coronary artery disease in humans.     

Combination Treatment of Melasma with Pulsed CO2 Laser Followed by Q-Switched Alexandrite Laser: A Pilot Study

BACKGROUND: Melasma is very difficult to treat and often refractory to treatment with topical creams and pigmented-lesion lasers. OBJECTIVE: Pulsed CO2 laser alone is compared with the combination of pulsed CO2 laser followed by Q-switched alexandrite laser in the treatment of dermal-type melasma. This combination is proposed to be effective by first destroying the abnormal melanocytes with the pulsed CO2 laser and then selectively eliminating the dermal melanin with the alexandrite laser. METHODS: Four patients were randomly chosen for each treatment arm. There were multiple follow-up visits for examination by an objective blinded investigator. RESULTS: All patients in the combination laser group showed complete resolution, and two patients in the CO2 laser only group had peripheral hyperpigmentation in the long-term follow-up evaluation. CONCLUSION: These laser therapies are safe, as there was no scarring and no infection. The combination laser therapy was highly effective in removing the hyperpigmentation and all patients in this group showed complete resolution without any peripheral hyperpigmentation.     

Principles of CO2/Erbium Laser Safety

BACKGROUND: There are a variety of potential hazards with laser technology. METHODS: A review of the literature. OBJECTIVE: To summarize the potential hazards of CO2 and erbium laser technologies and the safety guidelines and equipment developed to minimize them. RESULTS: Laser hazards can be divided into the following categories: mechanical, environmental, macrobiologic, microbiologic, and iatrogenic. CONCLUSION: At the conclusion of this learning activity, the reader should be able to discuss the mechanical, environmental, macrobiologic, microbiologic, and iatrogenic hazards of resurfacing laser technology, the literature cited to support current safety guidelines, and the equipment developed to promote laser safety.     

Laser Blepharoplasty: Diamond Laser Scalpel Compared to the Free Beam CO2 Laser

BACKGROUND: Blepharoplasty has long been employed for functional and cosmetic purposes. Different modalities have been utilized to incise and remove excess eyelid tissue in an attempt to improve surgical technique. OBJECTIVE: This study compares a free beam CO2 laser to a diamond surgical scalpel combined with a CO2 laser for performance of blepharoplasty. METHODS: Ten patients underwent bilateral upper lid blepharoplasty. One side was randomly assigned to the free beam CO2 laser technique, while the other side was performed with the diamond laser scalpel. Intraoperative surgical times and hemostasis were measured. Masked observers assessed postoperative parameters at day 1, week 1, week 2, week 4, and month 4. These assessments were analyzed clinically and statistically. RESULTS: The two modalities produced similar results for the intraoperative and postoperative parameters studied. CONCLUSION: The diamond laser scalpel has the advantage of tactile feedback and the option of use without coagulation.     

CO2 Laser Treatment of Epidermal Nevi: Long-Term Success

BACKGROUND: Epidermal nevi have been notoriously difficult to treat due to their large size and often conspicuous location. Variable results have been obtained with different laser treatments, and scarring and/or incomplete removal is typical after excisional or other destructive modalities. OBJECTIVE: To outline the successful use of a short-pulsed CO2 laser in the long-term eradication of epidermal nevi in three patients. METHODS: Three females (ages 15-19) presented with extensive grouped verrucous papules and plaques on the face, trunk, and extremities. A pulsed CO2 laser was used to vaporize the lesions using a 500 mJ pulse energy, 3 mm spotsize, and 7 watts of power. RESULTS: All lesions healed without incident. No lesional recurrence was observed 10 to 13 months after treatment except in one small area on the ankle in one patient. CONCLUSIONS: Carbon dioxide laser vaporization of epidermal nevi provides good clinical effect and offers unique advantages for the treatment of these lesions, including effective intraoperative hemostasis with excellent lesional visualization. It is also possible to treat widespread areas in one laser treatment session. While the results of this series clearly show the benefit of CO2 laser treatment, epidermal nevi may not always respond so favorably, due in part to the variability in their depths of involvement.     

Treatment of Fordyce Spots With CO2 Laser

BACKGROUND: Fordyce spots are heterotopic sebaceous glands that can be located at the lips' vermilion or the oral mucosa. Although this is considered a rather common disorder, a treatment for this condition that sometimes affects patients from only a cosmetic viewpoint has not yet been described. OBJECTIVE: To evaluate CO2 superpulsed laser treatment in two subjects with Fordyce spots. METHODS: Two patients with papules and yellowish plaques at the upper lip corresponding to Fordyce spots were treated with coherent Ambulase CO2 superpulsed laser (Coherent Medical, Palo Alto, CA); after informed consent was obtained, two to three passes were performed in one session using 2 and 4 W and a spot size of 2 mm. RESULTS: Complete re-epithelization was observed 2 weeks later with no residual Fordyce papules in the treated area and no side effects. CONCLUSION: Our findings suggest that CO2 superpulsed laser can be considered a safe and effective treatment for patients with Fordyce spots, offering excellent cosmetic results.     

Recurrent Ingrown Big Toenails Are Efficiently Treated by CO2 Laser

BACKGROUND: Surgery for onychocryptosis has a high rate of recurrence. OBJECTIVE: To evaluate CO2 laser partial matricectomy for recurrent onychocryptosis. METHODS: One hundred ninety-six consecutive patients (predominantly teenagers) previously unsuccessfully treated by surgery underwent CO2 laser for recurrent onychocryptosis. After a digital nerve block and a simple partial nail plate avulsion, the laser was used (5 W, defocused 2 mm beam in continuous mode) to vaporize the matrix, the lateral horn, and the lateral nail groove, including local granulation tissue if present. Follow-up was at least 12 months. RESULTS: Three hundred forty-four matricectomies were performed. Disease was mostly at stage II and III, with severe local infection in 24 cases (12.2%). All wounds healed in 21.9 +/- 3.2 days, with no postoperative local infection or prolonged exudative drainage. Onychocryptosis reoccurred in 5 of 344 treated margins (1.45%, average 15 months), all after primary bilateral matricectomy. Spicules in the lateral nail groove occurred in 14 of 344 treated margins (4%, average 5.9 months), mostly after primary bilateral matricectomy (7 cases) and in infected margins (8 cases). One patient developed a neuroma in the lateral nail groove. CONCLUSION: CO2 laser is effective for the treatment of recurrent onychocryptosis. Bilateral matricectomy and local infection seem to be the predisposing factors for recurrence and postoperative spicule growth.     

Free Internal Mammary Artery Graft: An Improved Surgical Technique

An improved method of free internal mammary artery (IMA)-to-ascending aorta anastomosis for coronary bypass is described. We interposed a small patch of vein with a suitable side-branch or branches in connecting the proximal end of a detached IMA or radial artery.Thirty-four free IMA-to-coronary artery bypasses were performed in 25 patients; 16 right IMA, 14 left IMA, and 4 radial arteries were used. Coronary angiographic follow-up studies performed in all patients between two weeks and six months after operation proved that all grafts were patent and showing a larger lumen than is usually seen in undetached IMA grafts. Concomitantly, marked relief of anginal pain was noted in all patients.Our experience with this technique is very encouraging. All patients are being followed to evaluate long-term graft patency.     

Minimally Invasive Coronary Surgery with Thoracoscopic Internal Mammary Artery Dissection: Surgical Technique

A bstract Background: We describe our technique of revascularization of the left anterior descending artery (LAD), using the left internal mammary artery (LIMA) without cardio- pulmonary bypass (CPB), by means of a 4-cm left thoracotomy and video-thoracoscopic harvesting of the LIMA. Methods: The patient is placed in a semioblique position. The LIMA is harvested under thoracoscopic guidance. Trocars are introduced via three thoracic incisions of less than 15 mm at the level of the fourth and seventh intercostal spaces. Perforating arterial branches are cauterized or clipped. This approach allows complete dissection of the LIMA from the subclavian artery to the fifth intercostal space. A 4-cm left anterior thoracotomy is then made along the fourth or the fifth intercostal space. Rib excision is not necessary for LAD exposure. Coronary artery control is obtained with looping sutures (4/0 prolene) placed proximally and distally to the site of the anastomosis. Anastomosis is then performed with 8/0 prolene on the beating heart, under direct vision, without CPB. Results : Between September 1995 and May 1996, this procedure was performed on 20 consecutive patients under age 80. There were no operative complications. The mean duration of hospitalization was six days. Conclusions : This new procedure enlarges the field of minimally invasive coronary artery bypass grafting techniques.