American Society for Laser Medicine and Surgery Abstracts 11

The therapeutic application of low-level laser irradiation in various fields has aroused interest regarding the action of laser light on whole organ systems including its interaction with whole blood. We have previously demonstrated that lymphocytes respond differently to laser light irradiation in the presence or absence of erythrocytes. The purpose the current study was to demonstrate the biostimulation effect of argon-dye (660nm) laser irradiation on monocytes in the presence or absence of erythrocytes. Methods: Monocytes were isolated from whole blood after irradiation at 660nm and a fluence of 5J or lo6 cells/ml monocy-te suspensions were irradiated under the same conditions in the absence of erythrocytes. The following parameters were monitored to demonstrate alterations in the biological functions of monocytes: morphological change, the production of ILl-p and IL-6 in response to Lipopolysaccharide (LPS). Varying concentrations of LPS were applied to lo6 cells/ml monocyte suspensions at doses of 0, 10, 20, 50-pg/ml. The dose response relationship was investigated. Results: No significant morphological changes were detected when monocytes were irradiated in the presence or absence of erythrocytes in comparison to non-radiated samples. A linear dose-response relationship \vas detected for ILI-I3 production. Slopes of the dose-response relation curves were: 2.52 pg /ml for the non-radiated sample and 3.72 pg/ml for the sample radiated in the absence of erythrocytes, and 4.82 pg/ml for the sample that was treated at 660nm in the presence of erythrocytes. Differences in the slopes were statistically significant (P < 0.05 t = 3.47 dfr4). Increased production of IL-6 was observed in the irradiated samples but no significant difference was detected when the treatment was performed in the presence of erythrocytes. Conclusion: These results suggest that erythrocytes play an important role in the biostimulatory effect of low-level laser irradiation on monocyte populations. Further studies of the effects of LLLT on whole organ systems are warranted.

STA’I‘U S AFTER MIJLTIPL,E TEII-:TH EXTRACTIONS TREATMENT WITH LOW LEVEL LASER THERAPY: A RANDOMISED CLINICAL, STlJDY WITH CONTROL GROUP. Zlatko Simunovic. Pain Clinic -- Laser Center, Locarno, Switzerland Kresimir Simunovic, Private Dental Practice, Zurich, Switzerland

Multiple teeth extraction is a dental surgical procedure, which is sometimes followed by complications I ike haemorrhage, oedema, pain and even inflammation. The current clinical study was conducted in order to observe the efficacy of Low Lebel Laser Therapy (LLLT) applied during and immediately after multiple teeth extractions. LLL,T was applied on patients (n-20). which were submitted to multiple teeth extractions, equally on upper and lower jaw. The control group ot patients (n--20) was treated with a classic post dental-surgical treatment. The laser device used in this study was a Helium Neon (HeNe) laser with 10 mW of output power coupled \vith an infrared diode laser. We have observed and scored local clinical parameters like haemorrhage, oedema, pain and redness. The occurrence of inllammation and intake of oral analgesic drugs were also obserwd in this study. LL,LT was applied using spot technique. Energy densit!, applied was 4 Joules per square centimeter. The results haw. demonstrated that patients irradiated with laser beam as indicated above did not experienced any local clinical symptom. The use of analgesic drugs was significantly lower and no infection was observed in the group of irradiated patients. Those results were different compared to outcome in the control group of patients where bleeding. oedema and pain occurred in three patients while two patients developed local inflammation. Some patients reported intake of oral analgesic drugs in the control group. In conclusion, despite of our good and promising results, further investigations and multicenter studies are necessary in order to establish LlLT as a standard procedure after multiple teeth extractions. due to the lack of complications and cost benetit.

40

EFFECTS OF HELIUM-NEON LASER ON MICROCRYSTALLINE ARTHROPATIES. V.Campana, M.Moya, AGavotto, J.Simes, L.Spitale, F.Soriano, H.Juri, J.Palma. Catedra de Fisica Biomedica. Facultad de Ciencias Medicas. Universidad National de Cordoba. Cordoba. Argentina. The microcrystalline arthropathies share in common the inflammatory response arising from or associated with the presence of different crystals in joints, such as the calcium pyrophosphate (CP), the deposit of which is the cause of pseudogota or chondrocalcinosis. Considering that fibrinogen as well as the tumoral necrosis factor (TNFcx) are important in regulating inflammation and immunity, they have been determined in the plasma of rats with arthropathies induced by CP to assess the antiinflammatory capacity of He-Ne Laser therapy in microcrystalline arthropathies. In addition anatomopathological (AP) studies were carried out. 2mg CP were injected in both joints of the lower limbs of rats during two days. A group were treated with laser of He-Ne (6 mW) on the injected joints during 3 consecutive days. After 96 hours of the first injection, animals were sacrificed by decapitation and the blood obtained was centrifuged to determine TNFol in plasma by Elisa and fibrinogen by spectrophotometry. Sections from the lower limbs were used for AP studies. A statistically significant increase (p<O.Ol) in plasma fibrinogen levels as well as in TNFa was observed in the group injected with CP, when compared to fibrinogen control group and laser treated group. The AP observations of the untreated group showed a great diffuse inflammatory reaction for mono and polymorphonuclears with fibro and angioblastic proliferation, with edematous lax stroma. On the contrary, no inflammatory reaction was observed in the group treated with laser of He-Ne. The treatment with He-Ne laser has an antiinflammatory effect to induce microcrystalline arthropathy in rats injected with CP, determined by fibrinogen and TNFa levels and by histological involution.

CARDIOVASCULAR, GENERAL SURGERY,

THORACIC, ORTHOPEDIC SURGERY

44

ND:YAG 1064nm RESECTION IN VIDEO-ASSISTED THORACOSCOPIC SURGERY OF MEDIASTINAL

LYMPHANGIOMAS

D. Cholewa’, J.Waldschmidt* University Childrens Hospital Basel, CH 4005 Basel, Postfach’

University Clinic Benjamin Franklin FU Berlin, D 12220 Berlin*

Bnckaround nrui Objective: The development of video-assisted endoscopic surgery enables thoracoscopy of mediastinal masses. The main problem in children is narrow preparation conditions.

12 American Society for Laser Medicine and Surgery Abstracts

Studs Design/Patients and Methods: Thirteen children with mediastinal lymphangiomas underwent thoracoscopy between 1995 and 2000. Four of the cases were already diagnosed before birth. Two to 3 trocars with a maximal diameter of 5 mm were placed. The Nd:YAG 1064 nm laser is extremely helpful in infants and small children. The small flexible laser fiber can be introduced into the intercostal space via a 14-gauge puncture cannula. Safe resection can be achieved by the fibertome mode.

Results: Representative tissue samples were obtained in all cases. There were no intraoperative complications. In one boy with a simple cystic lymphangioma and intraspinal involvement only the mediastinal portion could be extirpated. Thorax suction drainages were removed after l-3 days. Patients were discharged after 2-7 days. We found no lymphatic Iistulas after excision of the lymphangioma. Two years after surgery, a central lymphatic cyst was detected as a late complication.

Conchsion: Video-assisted thoracoscopic surgery is recommended as ,,first line“ treatment in mediastinal lymphangiomas.

45 OPTICAL COHERENCE REFLECTANCE GUIDED PERCUTANEOUS TRANSMYOCARDIAL LASER REVASCULARIZTION GrePorv. K.W., Teach, J., Viator, J.A., Oregon Medical Laser Center, Portland, OR Creating laser channels percutaneously for transmyocardial laser revascularization (TMR) has been limited to shallow channels due to fear of LV perforation and tamponade. Limited channel depth may limit the clinical benefit compared to transmyocardial TMR channels. We evaluated Optical Coherence Reflectometry (OCR) as a simple, inexpensive means of real-time assessment of laser ablated channel depth and proximity to the epicardium. An Intraluminal Therapeutics (ILT) OCR system used a low coherence LED at 13 10 nm (+30/-50 nm) to generate reflectance signals at tissue interfaces. The ILT OCR system was used to examine endocardium, intra-myocardium, and epicardial signals in vitro using fresh porcine hearts under saline. Reflection spectra for endocardium, intra-myocardial and epicardial signals were easily differentiated. The OCR system was then used to guide percutaneous TMR (PTMR) in 60kg anesthetized swine with a 308 nm excimer laser (Spectronetics) delivering light via a 1.7 mm laser catheter emitting SO mJ pulses at 25 Hz. The OCR fiber was placed in the central lumen of the laser catheter. Laser channels were created in the anterior and lateral walls of the left ventricle without perforation. When the endocardium was detected within 200-400 pm of the catheter tip, laser ablation was terminated. Angiography of the channels demonstrated blood flow into native coronary vasculature draining into the great cardiac vein without communication into the pericardium. Histologic sections showed near complete transmyocardial channels, no perforation, communication with native vessels and minimal acoustic injury. We conclude that OCR appears to be a feasible method to improve the safety and efficacy of percutaneous TMR.

46 *

EFFECT OF TRANSMY OCARDIAL LASER ON HEART FIJNCTION Elie E Hage-Korban, Hongbao Ma, Ruiping Huang, Terrence Whiteman, Mazen Al-Hamwy, Khalid Ghosheh, Joel Eisenberg, Oliver G Abela, George S Abela; Department of Medicine, Division of Cardiology, Michigan State University, East Lansing, Ml

Transmyocardial revascularization (TMR) relieves ischemic symptoms. However, heart failure is a major potential complication. This study evaluated the effect of TMR on myocardial function. Under general anesthesia, hearts were removed from 6 normal rats and placed in oxygenated physiologic solution at 34’C. The left ventricles (3.0 f 0.2 cm*) were dissected and mounted between a fixed post and a force displacement transducer. Electrical pulses (1 Hz/80 v) were used to stimulate the myocardium at 60 beats/min. TMR was performed by advancing a 300 pm core fiber while irradiating with a Ho:Yag laser (3 Hz, 280 mJ/pulse). Myocardial contractility (shortening in mm/pulse) was evaluated at increasing preloads (l-3 grams) after a series of 20 TMR channels. This was followed by 10 min rest and repeat 20 channels. This sequence was continued until myocardial dysfunction occurred. After 20 channels myocardial contractility decreased with loss of the Frank-Starling response (FSR). However, after 1.5 hr and 120 channels, myocardial contractility improved significantly with increasing preload conditions. Additional channels caused further loss of contractility.

This study demonstrated that TMR in rat hearts is associated with myocardial dysfunction. However, after 1.5 hr and 120 channels there was a consistent significant recovery of contractility and FSR. This may be due to myocardial preconditioning.

47 13IPKOVED STERILIZATION OF PROSTHETIC \‘ASCI’LAR GRAFTS I;SI3G SHOCK b’A\‘ES

Giuseppe R. Nigri’-“, Syhie Kosso~o’~~, Patrick FungaIoi’-‘, Shaumei Tsai”, Peter Watern~an’m”, David Hooper’, Apostoulos Doukas’, Glenn M. LaMuragIia’m” ‘Division of Vascular Surgery, ‘Infectious Disease Unit and ‘Wellman Laboratories of Photomedicine, Massachusetts Genera1 Hospital. Harvard Medical School. Boston, MA

Infection of vascular prosthetic grafts often results in sepsis, prolonged hospitalization, amputation and a 17% mortality. Bacteria that cause these infections proliferate and produce an exopolysaccaride matrix known as biofilm. The biofilm protects the bacteria by preventing antibodies. leukocytes and certain antimicrobial drugs affect the bacteria. It has previously shown that laser-generated shock waves (SW) can increase drug penetration into the biofilms. Bacteria (S. Epitlemidis) were cultured from infected prosthetic grafts obtained from patients. Dacron prosthetic vascular grafts w.erc sterilized and then inoculated with the isolated bacteria to allow them to proliferate and foml an adherent bacterial layer on both sides of the graft. The presence of the biofilm wras assessed by confocal microscopy. The infected grafts underwent the following treatments: a) saline alone, b) saline and S\%’ (23 ns Q-svvitched ruby laser). c) antibiotic (Vancomycin) alone, and d) antibiotic and SW. After treatment, grafts were sonicated to detach bacteria. the effluent was cultured and the colony forming units (CFIJ) wpere counted. CFU numbers in control specimens were comparable (saline. 3.05 N 10” 5 0.9) vs (saline/SW 3.3 1 x 10” + 0.9). The CFU number diminished to 7.61 x 10” L 0.5 after antibiotic treatment. Howeiyer the combined treatment (antibiotic and SW) synergistically decreased the CFU number ( 1.27 s 10’ 2 0.7) (p<O.OO 1). This study demonstrated that laser-generated shock waves can improve the delivery of antibiotics across prosthetic vascular graft biofilms, prov’iding direct access to bacteria. This is a new promising approach that can be used to improve antibiotic therapy to eradicate infection in prosthetic materials such as bypass grafts.

American Society for Laser Medicine and Surgery Abstracts 13

48 ARTHROSCOPIC LASER FACET RHIZOTOMY FOR CHRONIC LOW BACK PAIN Bonati, Alfred O., Wolff, Craig R., Mork, Anthony R., Tampa, FL.

Low back pain due to facet disease is common in society. Treatment with intraarticular cortisone injections has been shown to provide only temporary relief of symptoms. Radiofrequency rhizotomy is now commonly performed for facet disease, but the results reported show the limited success of this procedure. The purpose of this study is to review our results of arthroscopic laser facet rhizotomy for the treatment of chronic back pain due to facet disease. A retrospective review of 56 patients who had facet rhizotomy for chronic back pain between 1996 and 1998 was conducted. All patients were included only if they had greater than one year follow up and chronic symptoms, and all patients were required to complete a questionnaire designed for this study. There were 3 1 females and 25 males that had a mean age of 56 years and a mean duration of back pain of 7.8 years. 30% of patients had previous open back surgery. 1 patient had disease at L2/3, 7 patients at L3/4, 50 patients at L4/5, and 46 patients at L5/S 1. The mean follow up was 20 months. All patients had outpatient surgery, and no procedure related complications occurred. 64% of patients were classified as a good or excellent result at final follow up, and 36% as fair or poor results. At 3 month follow up 83% were classified as good or excellent result. This deterioration of results was statistically significant. When comparing patients who had good or excellent results with those who had fair or poor results there were no statistically significant differences. 65% of patients had relief of their back pain at final follow up, and 67% had relief of their buttock pain. 72% had satisfactory pain relief in the long term, and 76% had satisfactory function. 73% of patients would do the surgery again, and 74% would recommend the surgery to a friend. Arthroscopic facet rhizotomy is a safe and moderately effective procedure for patients with chronic back pain. The results do deteriorate with time: however, this is a simple outpatient procedure which can be repeated if back pain due to facet dysfunction returns, and it does not preclude future open back procedures.

49 LASER-ENDOSCOPY FOR LUMBAR DISC DECOMPRESSION

Michael W. Meriwether Sarasota, Florida

Outpatient laser-endoscopy with the holmium YAG laser for lumbar disc decompression is reviewed with a 36 months follow-up of 399 patients. Cri- teria of consideration were a history of leg pain radicular signs or symptoms, intractable sciatica failure to respond to a minimum of six months conservative care and an MRI scan demonstrating focal disc protrusion. Median duration of symp- toms was 11.2 months; average length of conserva- tive care was 8.7 months, and length of follow-up was 36 months. The criteria for success were met in 83.5% (333 patients), including relief of leg pain, off narcotic medications and return to work or basic functions. There were no infections and no nerve root injuries. Twelve patients came to open surgical intervention (3%). Patient selec- tion and technical considerations (at least 20 kilojoules of laser energy expenditure per disc) are important factors in assessing the efficacy of this procedure. This data suggests that a minimally invasive approach to laser disc exci- sion is a viable first stage alternative to open surgery.

50

BIOMODULATION OF LIGHT ON CELLS IN TRANSMYOCARDIAL LASER REVASCULARIZATION Timon Cheng-Yi Liu, Rui Duan, Yan Li and Yan-Ling Li Laboratory of Light Transmission Optics, South China Normal University, Guangzhou, GD, China Previous research on transmyocardial laser revascularization have been reported open channels after ultraviolet (UV) laser treatment and closed channels with infrared (IR) lasers. In this paper, the biological information model of low intensity laser (BIML) is used to understand these phenomena. Although the central intensity of the laser beam is so intense that it destroys the tissue, the edge intensity is so low that it can induce biostimulation. According to BIML, the UV laser irradiation can inhibit immune response and inflammatory response, induce the synthesis of collagen fiber which are aligned approximately parallel to the long axis of the channel, and then protect the channel against thrombus and scar. At this point, it is believed that cold color (violet, blue or green) laser will play a role similar to UV laser in terms of BILM. In other words, biostimulation of light on cells might play an important role in the long- term effect of transmyocardial laser revascularization.

51 PROPHYLACTIC LAPAROSCOPIC ND:YAG 1064nm LASER

GONADECTOMY IN GONADAL DYSGENESIS

D. Cholewa’, D. vonschweinitz’, A. Kischkel’, J.Waldschmidt2 University Childrens Hospital Basel, CH 4005 Basel, Postfach’

University Clinic Benjamin Franklin FU Berlin, D 12220 Berlin2

Background and Objective: The aim of the study was to evaluate if laparoscopy is an alternative to laparotomy for prophylactic gonadectomy in patients with gonadal dysgenesis (46, XY and 45 X01 46 XY).

Study Design/Patients and Methods: The Nd:YAG 1064 nm laser contact dissection of the pelvic ligaments and the removal of the dysgenetic gonads was in 10 children. The 600 pm bare fiber was introduced via puncture cannulas or a special instrument, which allows angulation of flexible light conductor. With the fiber-tom mode, the temperature at the fiber tip is measured and adapted by optical feedback. The tibertom+C mode adds short single pulses to eliminate carbonization residues from the fiber. This keeps the laser knife sharp at all times and ensures a more reliable laparoscopic excision.

Results: The average operation time was 75 minutes (45-140), the average blood loss was 27.5 ml (1 O-60) and the average hospital stay was 2.5 days. Histological examinations found neoplasia in 6 patients (3 testicular intraepithelial neoplasia, 5 gonadoblastoma, 1 dysgerminoma).

Conclusion: Laparoscopic laser gonadectomy is a safe and effective procedure in prophylactic surgery in gonadal dysgenesis.

52 ND:YAG 1064nm LASER THERAPY IN LAPAROSCOPY OF

LIVER CYSTS IN INFANTS

D. Cholewa’, J.Waldschmidt2 University Childrens Hospital Basel, CH 4005 Basel, Postfach’

University Clinic Benjamin Franklin FU Berlin, D 12220 Berlin’