Biomedical subjects

X M Mueller

Publications and source records attributed to X M Mueller.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Laser transmyocardial revascularization--a potential risk in an acute situation?].

Morphological and functional effects of transmyocardial laser revascularization (TMLR) are analyzed in an acute setting on a porcine model. Ten channels were drilled in the left lateral wall of the heart of 15 pigs (mean weight, 73 +/- 4 kg) with a Holmium-YAG laser (wavelength: 2.1 mu, probe diameter: 1.75 mm). Echocardiographic control was performed before the TMLR procedure as well as 5 min and 30 min thereafter. Echocardiographic parameters were recorded in short-axis at the level of the laser channels, and included left ventricular ejection fraction, fractional shortening and segmental wall motility of the channels' area (scale 0-3: 0 = normal, 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). After sacrifice the lased region was sliced perpendicularly to the channels for histological and morphometrical analysis. Five minutes after the drilling of the channels, all the echocardiographic index worsened significantly in comparison with baseline values (p < 0.01). All recovered after 30 min and showed no difference with baseline values. Cross-section of the channel lesions measured 8.8 +/- 2.4 mm2 which is more than three times that of the probe (p < 0.01). In acute conditions, the lesions due to the TMLR probe are significantly larger than the probe itself and cause a transient drop of the segmental wall motility on a healthy myocardium. These results suggest that TMLR should be used cautiously in the clinical setting for patients with an impaired ventricular function.

Animals↗

PubMed2000

Anastomotic longitudinal stress due to modification of arterial longitudinal properties after anastomosis.

BACKGROUND: In our hands, in vivo segmental vessel length changes up to 5% because of blood pressure: increasing in arterial pressure is associated to decrease in segmental vessel length. METHODS AND MATERIAL: Using two piezoelectric crystals sutured on vessel wall and a high fidelity pressure probe, we recorded artery length variations as function of blood pressure, before and after an end-to-end anastomosis on four pigs carotid arteries. RESULTS: Mean arterial pressure before anastomosis = 73 mmHg (+/- 12); mean arterial pressure after anastomosis = 91 mmHg (+/- 14); mean crystals displacement before anastomosis during systole = -0.21 mm; mean crystals displacement after anastomosis during systole = +0.24 mm; mean distance between crystals before anastomosis = 12.3 mm (+/- 0.8) and after anastomosis = 11.2 mm (+/- 0.5). CONCLUSIONS: In the acute phase following an end-to-end anastomosis, an increase in blood pressure causes increasing in vessel length, with an exponential correlation. The anastomosis is constantly subjected to a longitudinal traction whose magnitude depends on blood pressure.

Anastomosis, Surgical↗

PubMed2000

Decreased compliance on arterial anastomoses.

UNLABELLED: The present study was undertaken to examine the cross-sectional vascular compliance at the anastomotic site. METHODS AND MATERIAL: We performed end-to-end anastomosis on the carotid artery of six pigs using continuous 6/0 polypropylene. Four carotid arteries were excised and mounted in a perfusion chamber while the remaining two were left in living animals. We used pulsed ultrasound (NIUS 02) to generate detailed longitudinal profiles of diameter and compliance in the proximity and on the anastomosis. RESULTS: On the anastomosis, the vessel diameter decreases (-1 to -2.6% of diastolic diameter) when blood pressure increases with an exponential correlation (R2 = 0.75). The arterial compliance at the anastomosis was negative: the vessel cross-section reduction for a pulse pressure of 1 up to 32 mmHg was 0.9 to 2% of diastolic vessel cross-section. CONCLUSIONS: Vessel movement generated a dynamic stenosis whose magnitude seems to depend on blood pressure level. Increasing blood pressure causes the retraction of vessel ends which causes vessel lumen reduction. These results suggest that continuous suture does not provide the continuity of mechanical properties of the artery.

Anastomosis, Surgical↗

PubMed2000

[Endothelial lesions caused by intra-aortic counterpulsation balloons].

Intra-aortic balloon pump (IABP) is the most frequently used mechanical circulatory support. Repeated trauma on the aortic wall has been reported as a cause of balloon perforation by endothelial denudation of atheromatous plaque. This study analyses the effect of IABP on the endothelium of the calf aorta. In 12 calves (mean weight: 72 +/- 6 kg) an IABP was inserted by femoral route and left during 6 hours on internal mode with a frequency of 80 cycles/min. The animals were sacrificed after the procedure (n = 4), at postoperative day (POD) 7 (n = 4), and at POD 14 (n = 4). In the aorta facing the balloon, nine transmural samples were taken proximally (n = 3), at mid height (n = 3) and distally (n = 3), for histological analysis of the percentage of aortic surface covered with endothelium. The percentage of aortic surface covered with endothelium at POD 0, 7 and 14 was proximally: 72.5 +/- 27.5%, 83.7 +/- 16.9% and 93.3 +/- 8.9% respectively; at mid-height: 50.8 +/- 30.7%, 65 +/- 25% and 95 +/- 5%; and distally: 31.4 +/- 20.1%, 48.3 +/- 34.4% and 85 +/- 10%. A large portion of the aortic endothelium is abraded after 6 hours of IAB pumping. This effect is more important at the distal level of the aorta. After two weeks, most of the endothelium has regenerated.

Animals↗

PubMed2000

[Surgical repair of aortic coarctation in adults over 30 years of age].

Coarctation of the aorta is nowadays rarely observed among adult population, as it is usually detected and treated during infancy. The natural history of this disease however is known to lead to early death due to the consequences of severe arterial hypertension. We report on 3 patients older than 30 years, recently operated on in our cardiosurgical units. Two of them were foreigners recently arrived in Switzerland, of 46 and 32 years old respectively. The medical examination highlighted severe hypertension and bilateral absence of femoral pulses. The third patient was a Swiss citizen and had a similar examination. Chest X-rays clearly showed rib notching, and the suspected diagnosis was confirmed with angiography. Three different surgical techniques were chosen, according to the peroperative situation. In one case, the stenosis was resected and an end-to-end anastomosis could be performed. In another case, the occlusion was complete and extended over 3 centimeters. The resected segment was replaced by a prosthetic graft. In the third case, we performed a synthetic patch graft aortoplasty. Postoperative care were simple in every cases. Coarctation of the aorta must be evoked among the possible etiologies of severe hypertension, as the surgical treatment is of real benefit and with reduced morbidity.

Adult↗

PubMed2000

3-D vision improves performance in a pelvic trainer.

BACKGROUND AND STUDY AIMS: Experienced endoscopic surgeons have adapted to the absence of depth perception while using two-dimensional (2-D) visualization. However, three-dimensional (3-D) vision may prove useful at least at the beginning of the learning curve in celioscopic training. METHODS: In a pelvitrainer with a fixed camera, two skill tests were designed to assess the performance of three groups of operators: "non-surgeons", "non-celioscopist surgeons", and "trained celioscopists". In the first test, the candidate had to touch with a needle a sequence of dots distributed on a 7.1-cm2 area. In the second test, a 6-0 C-1 needle had to be passed consecutively through two 1-mm holes made in a thin vertical plastic wall. Each test was performed ten times, using either 2-D vision (five times) or 3-D vision (five times) interspersed in a random manner. RESULTS: In both tests and within each group, performance was related to the experience of the operator, with the trained celioscopists' group obtaining the best results and the non-surgeons the worst. In every situation, including the trained celioscopists' group, 3-D vision significantly improved performances. No significant difference was observed between the results of the non-celioscopist surgeons' group using 3-D vision and those of the trained celioscopists' group using 2-D vision. CONCLUSIONS: 3-D vision improves the performance and accuracy of endoscopic surgeons. It provides a visual perception "close to reality", and helps celioscopic beginners to accelerate their training.

Adult↗

PubMed2000

Assembly of the Heparin Removal Device for patients with suspected adverse reaction to protamine sulphate.

Protamine sulphate is routinely used after cardiopulmonary bypass (CPB) to restore the patient's baseline coagulatory state. However, adverse reactions are encountered, and alternative means to neutralize heparin are, therefore, necessary. The Heparin Removal Device (HRD) constitutes an extracorporeal circuit that allows ex vivo deheparinization by mean of a polycationic ligand that binds heparin molecules. This paper presents the setup of the HRD circuit. It is illustrated by the report of a 68-year-old man with a known severe crustacean allergy. The patient (78 kg, 170 cm) was admitted for elective coronary artery bypass graft surgery. It was decided that the HRD would be used as a precaution in order to avoid the risks of using protamine sulphate. The CPB time and aortic crossclamp time were 70 and 40 min, respectively. At the end of CPB, the device was inserted and processing started. Activated coagulation time values were monitored over a 130 min period and diminished from 480 to 300 s after 45 min, 220 s after 90 min, and settled at 150 s. Haemostasis was acceptable and processing stopped. The operation was terminated and the patient transferred to the intensive care unit. Clinical evolution was excellent, with minimal postoperative bleeding. The HRD presents an alternative to protamine sulphate when this drug is contraindicated for a certain patient population who might have a suspected, known or emergency adverse reaction.

Aged↗

PubMed2000

Pain location, distribution, and intensity after cardiac surgery.

STUDY OBJECTIVES: To study the location, distribution, and intensity of pain in a sample of adult cardiac surgery patients during their postoperative hospital stay. DESIGN: In a prospective study, pain location, distribution (number of pain areas per patient), and intensity (0 to 10 numerical rating scale) were documented on the first, second, third, and seventh postoperative day (POD). Patient characteristics (age, sex, size, and body mass index) were analyzed for their impact on pain intensity. SETTING: A university hospital. PATIENTS: Two hundred consecutive adult patients who underwent median sternotomy for open heart surgery. There were 121 male and 79 female patients, with a mean (+/- SD) age of 60.9 +/- 19.2 years. MEASUREMENT AND RESULTS: The maximal pain intensity was significantly higher on POD 1 and 2 (3.7 +/- 2 and 3.9 +/- 1.9, respectively) and lower on POD 3 and 7 (3.2 +/- 1.5 and 2.6 +/- 1.8, respectively). The pain distribution did not vary significantly throughout the hospital stay, but the location did, with more shoulder pain on POD 7. Only age was found to have an impact on pain intensity, with patients < 60 years having a higher pain intensity than older patients on POD 2 (4.3 +/- 2.2 vs 3.6 +/- 2.4; p = 0.02). CONCLUSIONS: In this patient population, the pain intensity diminished from POD 3 onward, although its distribution did not vary significantly during the first postoperative week. Moreover, pain location changed with time, with more osteoarticular type pain at the end of the first postoperative week. Among the patients' characteristics, only younger age had an impact on pain intensity, with a higher value on POD 2.

Adolescent↗

PubMed2000

Blood profile during and after hemoglobin substitute administration.

The in vivo effects of Diaspirin Crosslinked Hemoglobin (DCLHb, Baxter Healthcare Corp.) on hematology and biochemistry are unknown. This study includes 6 calves (71.2+/-1.3 kg). In each animal a total of 2 litres of blood was exchanged for the same amount of hydroxylethyl starch (Haes, Fresenius) (n=3) or DCLHb (n=3), which is equivalent to 28cc/kg of blood substitute, over a period of 5 hours. The animals were allowed to survive 7 days. Blood samples were taken hourly during the perfusion protocol, at postoperative day (POD) 1, 2 and 7. ANOVA test was used for repeated measurements. Blood cell profiles were similar in both groups. Peak methemoglobinemia was 4.2% in the DCLHb group. Osmolarity was significantly higher in the DCLHb group with the greatest difference at POD 1 and 2. Postmortem analysis of the major organs did not show any sign of hemoglobin deposit in the DCLHb group. In the given setup DCLHb can be administered in a large quantity with good hematological tolerance and without any deposits in major organs. A prolonged plasma expander effect was observed.

Analysis of Variance↗

PubMed2000

[Closure of an atrial septal defect by a mini-thoracotomy with the help of extra-corporal circulation].

AIM OF THE STUDY: "Minimal invasive" surgical closure of an atrial septal defect (ASD) is performed under femoro-femoral CPB, the superior vena cava being (IVC) drained by a supplementary cannula placed directly through the thoracic opening. We present a new technique where both vena cavae are drained by a single 2 stage femoral cannula. METHODS: The cannula is introduced through the femoral vein and its distal holes are directed into the superior vena cava (SVC) while the proximal holes are maintained into the IVC. A centrifugal pump is placed on the venous line between the cannula and the venous reservoir in order to improve the venous return. Both IVC and SVC are clamped around the cannula to isolate the right atrium before opening it and repairing the ASD. RESULTS: We recently operated on a 60 years old man using this technique. Passive venous drainage was 2.6 l/min whereas the perfusion theoretical flow was 5.4 l/min. But adding the centrifugal pump increased the flow to 5.4 l/min which ensured an optimal perfusion flow. CPB time was 38 minutes and operative time was 140 minutes. There were no complications and the patient returned home at day 5 following the operation. CONCLUSIONS: Using a single venous cannula for drainage of both vena cavae simplifies the technique and therefore contributes to the development of "minimally invasive" cardiac surgery.

Cardiopulmonary Bypass↗

PubMed2000

Improved neoangiogenesis in transmyocardial laser revascularization combined with angiogenic adjunct in a pig model.

Recent research has revealed neoangiogenesis as a basic phenomenon in transmyocardial laser revascularization (TMLR). Theoretically, myocardial neoangiogenesis could be further enhanced by the addition of angiogenic growth factors. Triads of TMLR channels were created in the lateral wall of the left ventricles of 12 pigs (mean body weight 73+/-5 kg), using a holmium:yttrium-aluminium garnet (YAG) laser. The animals were allocated randomly either to receive an injection of 100 microg of a bovine bone-derived growth factor mixture within the triads (n=6), or to a control group (n=6). Animals were killed 1 month later. Capillary and arteriolar densities were determined by computed morphometric analysis of histological sections of the triads. The capillary density of myocardial areas within the triads was significantly greater in the group receiving the bovine bone-derived growth factor mixture than in the control group (14.3+/-3.5/mm(2) and 5.7+/-1.4/mm(2) respectively; P<0.001). The difference was also significant when considering arteriolar density (0.7+/-0.4/mm(2) and 0.2+/-0.1/mm(2) respectively; P<0.001). For comparison, capillary and arteriolar densities of the TMLR channel scars were 48.7+/-9.7 and 1.9+/-0. 5/mm(2) respectively in the angiogenic group, and 46.3+/-13.7 and 2. 3+/-1.3/mm(2) respectively in the control group (no significant differences). These results demonstrate that the addition of angiogenic factors to TMLR stimulates neoangiogenesis significantly in the areas adjacent to the channels, but not within the channel scars. The latter are themselves strongly vascularized. Hence this combined approach, potentiating the effect of TMLR by establishing vascular connections between the neovessels of the channel scars, has the potential for improved clinical outcome.

Animals↗

PubMed2000

Impact of hollow-fiber membrane surface area on oxygenator performance: Dideco D903 Avant versus a prototype with larger surface area.

This study compares the gas transfer capacity, the blood trauma, and the blood path resistance of the hollow-fiber membrane oxygenator Dideco D 903 with a surface area of 1.7 m2 (oxygenator 1.7) versus a prototype built on the same principles but with a surface area of 2 m2 (oxygenator 2). Six calves (mean body weight: 68.2 +/- 3.2 kg) were connected to cardiopulmonary bypass (CPB) by jugular venous and carotid arterial cannulation, with a mean flow rate of 4 l/min for 6 h. They were randomly assigned to oxygenator 1.7 (N = 3) or 2 (N = 3). After 7 days, the animals were sacrificed. A standard battery of blood samples was taken before the bypass, throughout the bypass, and 24 h, 48 h, and 7 days after the bypass. The oxygenator 2 group showed significantly better total oxygen and carbon dioxide transfer values throughout the perfusion (p < .001 for both comparison). Hemolytic parameters (lactate dehydrogenase and free plasma hemoglobin) exhibited a slight but significant increase after 5 h of bypass in the oxygenator 1.7 group. The pressure drop through the oxygenator was low in both groups (range, 43-74 mmHg). With this type of hollow-fiber membrane oxygenator, an increased surface of gas exchange from 1.7 m2 to 2 m2 improves gas transfer, with a limited impact on blood trauma and no increase of blood path resistance.

Animals↗

PubMed1999

[Minimally invasive coronary bypass: optimal performance after a learning period].

Minimally invasive cardiac surgery requires a learning period before the advantages of the method can be demonstrated. We report the progress of our results over 21 consecutive months. 27 patients were considered for minimally invasive coronary bypass via a small thoracotomy. We compare the results of four consecutive groups corresponding to an initial period (July-December 1997; n = 7; 66.8 +/- 8.9 years), an intermediate period (January-June 1998; n = 4; 48.1 +/- 11.2 years), an advanced period (July-December 1998; n = 7; 62.9 +/- 7.0 years) and a current period (January-March 1999; n = 7; 59.3 +/- 10.9 years). 2 patients were converted to sternotomy during the first year of experience. The operating time was reduced from 124 +/- 14 min and 118 +/- 20 min during the initial and intermediate periods to 99 +/- 18 and 98 +/- 18 min during the last two periods. The ICU stay was 2.6 +/- 1.1 days during the initial period and diminished respectively to 1.5 +/- 0.6, 1.7 +/- 0.8 and 1.6 +/- 0.5 days during the intermediate, advanced and current periods. The postoperative hospital stay was reduced from 9.0 +/- 1.4 days to 6.3 +/- 4.6, 5.2 +/- 1.7 and 5.9 +/- 1.5 days respectively. The benefits of minimally invasive coronary bypass were estimated by comparing the results of the last two periods with those of patients operated on through a sternotomy, on a beating heart (n = 12; 62.6 +/- 8.2) or under CPB (n = 81; 63.0 +/- 8.5). In these situations, operative time was 144 +/- 41 min and 180 +/- 35 min respectively. The ICU stay was 1.5 +/- 0.6 and 2.2 +/- 0.9 days, and the postoperative hospital stay was 7.5 +/- 2.8 and 8.6 +/- 3.0 days. We conclude that a learning period is necessary before the real benefits of the minimally invasive approach to coronary disease can be demonstrated. This method will soon replace traditional sternotomy in certain indications.

Aged↗

PubMed1999

[Mechanism of action of transmyocardial laser revascularization (animal experiment)].

Transmyocardial laser revascularisation (TMLR) has emerged as an efficient treatment for angina refractory to conventional therapies. Moreover, some studies have suggested improvement of cardiac function. Its mechanism of action, initially attributed to blood flow from the ventricular cavity through the channels toward the ischaemic myocardium, remains to be defined. 21 pigs were randomised to TMLR of the left lateral wall (TMLR group; n = 7), to myocardial infarction (MI group; n = 7), or to both (TMLR-MI group; n = 7). In each group one animal was sacrificed at postoperative day 0, 7, 14 and 21, and 3 animals at postoperative day 28. The lateral wall of the left ventricle was fixed in 4% formaldehyde and sliced in a plane perpendicular to the channels for histological analysis. The evolution of the cross-section area of the lesions as well as their vascular densities at postoperative day 28, expressed as number vascular structures per mm2, were studied. All the channels were occluded by a clot at postoperative day 0 and by scar tissue at postoperative day 28. The cross-section area of the lesions diminished from 8.1 +/- 1.3 mm2 at postoperative day 0 to 2.4 +/- 0.2 mm2 at postoperative day 28. At postoperative day 28, the vascular density of scar tissue of the channels in the TMLR group was significantly increased in comparison with that of myocardial infarction in the MI group (47.1 +/- 10.2 vs. 23.8 +/- 9.1; p < 0.01). In the TMLR-MI group, channels scar became indistinguishable from surrounding myocardial infarction scar. In this model, laser channels are occluded early and do not salvage acute ischaemic myocardium. Mechanisms which could explain clinical improvement, as suggested by the results, are intense laser-induced neovascularisation and channel scar retraction (Laplace's law).

Animals↗

PubMed1999

Imaging of the abdominal aorta during examination of patients referred for transthoracic echocardiography.

BACKGROUND: Screening for aneurysm of abdominal aorta (AAA) in the general population is costly and unrealistic, but examination of the abdominal aorta appears reasonable in a high risk cardiological population. METHOD: As the abdominal aorta is easily accessible to standard transthoracic echocardiographic equipment, we tested this hypothesis in 301 consecutively referred patients (182 men, 119 women, mean age 58.6 +/- 16.5 years) by imaging the abdominal aorta at the end of the cardiac examination. RESULTS: After exclusion of three patients operated on for AAA before, the native infrarenal segment most often involved in AAA was visualised in 297 out of 298 patients (99.7%), and the aortic bifurcation was seen satisfactorily in 285 of them (95.6%). The abdominal aorta was dilated (> or = 2 cm) in 44 patients (15%), all but one of whom were > 50 years old; 17 of these (5.7%) had AAA defined as segmental dilation with a maximum diameter of > or = 3 cm (15 men, 2 women, age 67.4 +/- surgical repair and one endovascular repair within one year after completion of the data collection. Their mean age was 70.1 +/- 7.9 years, ranging from 58 to 80 years. No significant surgical morbidity and no mortality was observed. CONCLUSIONS: Prevalence of dilative alterations of the abdominal aorta is high in cardiological patients. Visualisation during transthoracic echocardiography of the most important infrarenal segment is nearly always feasible (99.7%), including its bifurcation (95.6%). Since detection of life-threatening but asymptomatic AAA may save lives by offering safe elective surgical treatment or stenting, opportunistic examination of the abdominal aorta during routine transthoracic echocardiography, which involves little time and no additional cost, would appear to be highly effective and should be included in routine examinations, at least in patients over 50 years of age.

Adult↗

PubMed1999

Myocardial scarring after transmyocardial laser revascularization: A potential mechanism of clinical improvement?

BACKGROUND AND OBJECTIVE: The morphological evolution of transmyocardial laser channels was analyzed in a pig model. MATERIALS AND METHODS: Five channels were created in the lateral wall of the left ventricle of 12 animals, using a Ho:YAG laser. In half of the animals, an additional infarction was induced in the same area. Animals were sacrificed at one-week intervals until week 5 and the critical regions of the left ventricular wall were subjected to microscopic computed morphometrical analysis. RESULTS: There was no clearly patent lumen at any stage. Cross-sectional area of the channels fell from 8.5 +/- 1.2 mm(2) at day 0 to 2.1 +/- 0.1 mm(2) at day 35. From day 7 onward, the channel area was gradually replaced by granulation tissue and the proportion of the channel occupied by granulation scar tissue increased from 37 +/- 2% at day 7 to 100% at day 28. In the subgroup with concomitant infarction, granulation tissue of both channel and infarction became indistinguishable from day 14 onward. CONCLUSIONS: These results suggest strongly that channel patency is not the mechanism of angina relief after transmyocardial laser revascularization with Ho:YAG laser.

Animals↗

PubMed1999

Gastrointestinal disease following heart transplantation.

With advances in heart transplantation, a growing number of recipients are at risk of developing gastrointestinal disease. We reviewed our experience with gastrointestinal disease in 92 patients undergoing 93 heart transplants. All had follow-up, with the median time 4.8 years (range 0.5-9.6 years). During the period of the study we progressively adopted a policy of low immunosuppression aiming toward monotherapy with cyclosporine. Nineteen patients (20.6%) developed 28 diseases related to the gastrointestinal tract. Thirteen patients required 18 surgical interventions, five as emergencies: closure of a duodenal ulcer, five cholecystectomies (one with biliary tract drainage), a sigmoid resection for a diverticulitis with a colovesical fistula, a colostomy followed by a colostomy takedown for an iatrogenic colon perforation, appendectomy, two anorectal procedures, and six abdominal wall herniorrhaphies. At the onset of gastrointestinal disease, 8 patients were on standard triple-drug immunosuppression, all of them within 6 months of transplantation; 13 were on double-drug immunosuppression; and 7 were on cyclosporine alone. All the patients with perforations/fistulas were on steroids. Among the 11 infectious or potentially infectious diseases, 10 were on triple- or double-drug immunosuppression. One death, a patient who was on triple-drug immunosuppression, had a postmortem diagnosis of necrotic and hemorrhagic pancreatitis. Except for an incisional hernia following a laparoscopic cholecystectomy, there was no morbidity and, importantly, no septic complications. We concluded that a low immunosuppression policy is likely to be responsible for the low morbidity and mortality of posttransplant gastrointestinal disease, with a lower incidence of viscous perforation/fistula and infectious gastrointestinal disease.

Adolescent↗

PubMed1999

Advantages of a modified gastroscope for video-assisted internal mammary artery harvesting.

Instead of standard rigid thoracoscopes, we used a modified gastroscope for video assistance during 12 minimally invasive left internal mammary harvesting. Flexibility and remote control of its last centimeters give to the gastroscope a total freedom of movements, and perfect positioning in every direction. The scope is equipped with cold light, a suction canal and an irrigation canal, which allow for in situ washing without needing to remove it from the thoracic cavity. Thanks to these advantages, vision and lighting are always perfect.

Endoscopes↗