Advances in the raw material selection and functional design of artificial nerve guidance conduits / 生物工程学报

Artificial nerve guidance conduits (NGCs) are synthetic nerve grafts that are capable of providing the structural and nutritional support for nerve regeneration. The ideal NGCs have plenty of requirements on biocompatibility, mechanical strength, topological structure, and conductivity. Therefore, it is necessary to continuously improve the design of NGCs and establish a better therapeutic strategy for peripheral nerve injury in order to meet clinical needs. Although current NGCs have made certain process in the treatment of peripheral nerve injury, their nerve regeneration and functional outcomes on repairing long-distance nerve injury remain unsatisfactory. Herein, we review the nerve conduit design from four aspects, namely raw material selection, structural design, therapeutic factor loading and self-powered component integration. Moreover, we summarize the research progress of NGCs in the treatment of peripheral nerve injury, in order to facilitate the iterative updating and clinical transformation of NGCs.

Research progress on dental pulp stem cells in the repair of peripheral nerve injury / 口腔疾病防治

@#Peripheral nerve injury (PNI) is a common disease in the oral cavity that can easily lead to loss of function and abnormal appearance. The application of dental pulp stem cells (DPSCs) combined with tissue engineering in the repair of PNI is a research hotspot. DPSCs have the advantages of abundant sources, simple extraction, low immunogenicity and a high proliferation rate in vitro. They can differentiate into Schwann cells (SCs). SCs can induce autophagy and secrete key neurotrophic factors, such as nerve growth factor, brain-derived neurotrophic factor, ciliary neurotrophic factor and glial cell-derived neurotrophic factor. SCs are beneficial for the repair of nerve injury. DPSCs in different periods have differences in immune regulation, anti-inflammatory effects, expression of neural markers, angiogenesis and so on, which provide more diversified choices for nerve repair. At present, the introduction of tissue engineering provides a more controllable and improved microenvironment for DPSCs, which is conducive to the application and development of DPSCs in regenerative medicine and tissue engineering. However, there are still many problems to be solved, such as the selection of stem cells, functional link recovery, uncontrollable direction of axon regeneration, regulation of the peripheral nervous system and mechanism of repair.

Fontan Revision with Y-Graft in a Patient with Unilateral Pulmonary Arteriovenous Malformation

The extracardiac conduit Fontan procedure is the last surgical step in the treatment of patients with a functional single ventricle. An acquired pulmonary arteriovenous malformation may appear perioperatively or postoperatively due to an uneven hepatic flow distribution. Here we report a case of a bifurcated Y-graft Fontan operation in a 15-year-old male patient with a unilateral pulmonary arteriovenous malformation after an extracardiac conduit Fontan operation.

The modification research of bionic silk fibroin nerve guidance conduits by silk sericin / 中华显微外科杂志

Objective To explore the modification of bionic silk fibroin nerve conduits (SF-NCs) by silk sencin.Methods The innovative SS/SF blended-NCs was fabricated by a vertical sequential cooling thermal induced phase separation (TIPS) processing with SF solution added sericin in proportion,its morphology was observed by Scanning electron microscopy (SEM),X-ray diffraction (XRD) and infrared spectroscopy (FTIR) were used to detect its internal molecular structure.MTT assay was used to quantitatively analyzed the PC12 cells viability co-cultured with the innovative SS/SF-NCs,SEM was used to observe the adhesion and morphology of PC12 cells seeded into the innovative SS/SF,PC12 cells were used to assess the NGF bioactivity released from the SS/SF.Results The SEM results showed that the new fabricated SS/SF-NCs had linearly oriented lamellar-like multiple-channel which distributed evenly,got great changes on the channel microstructure and their mechanical properties had been greatly improved,compared to SF-NCs.The XRD and FTIR results showed that the SS/SF-NCs had the similar internal molecular structure with natural silk.The spaces between parallel lamellar-like channels,porosities and compressive strengths of the SS/SF-NCs decreased with decreasing Sequential freezing temperature.MTT assay results showed that the viability of PC12 cell was better than the control group (P ＜ 0.05).The SEM observation indicated that PC12 cells showed good adhesion and differentiation with neuritis outgrowth during the period of co-culture with the SS/SF-NCs.NGF release from the innovative SS/SF-NCs was prolonged over 4 weeks,and remained bioactive.Conclusion The new fabricated SS/SF-NCs modified though silk sericin,which was highly bionic the structure of peripheral nerve fasciculus,had excellent mechanical properties and could be used as another alternative of artificial nerve conduits.

Conduits for Coronary Bypass: Strategies

Strategic planning is integral to any operation but complexity varies immensely and therefore the effort necessary to create the optimal plan. The previous three reports have discussed individual conduits and herein is an attempt to present approaches to common situations which the author favors. Although much has been learned over 45 years about use and subsequent behavior of venous and arterial grafts we continue to learn and, as a result, evolve new strategies or modify those now popular. Thus the reader must recognize that in spite of trying to be balanced and inclusive all surgeons have personal opinions and also prejudices which influence the approach taken and which may not be the optimal one for others or for the patient.

Nafamostat Mesilate: Can It Be Used as a Conduit Preserving Agent in Coronary Artery Bypass Surgery?

BACKGROUND: Graft vessel preservation solution in coronary artery bypass surgery is used to maintain the graft conduit in optimal condition during the perioperative period. Nafamostat mesilate (NM) has anticoagulation and anti-inflammatory properties. Therefore, we investigated NM as a conduit preservative agent and compared it to papaverine. METHODS: Sprague-Dawley (SD) rat thoracic aortas were examined for their contraction-relaxation ability using phenylephrine (PE) and acetylcholine (ACh) following preincubation with papaverine and NM in standard classical organ baths. Human umbilical vein endothelial cells (HUVECs) were cultured to check for the endothelial cell viability. Histopathological examination and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were performed on the thoracic aortas of SD rats. RESULTS: The anti-contraction effects of papaverine were superior to those of NM at PE (p90% in various concentrations of both NM and papaverine. A histopathological study showed a protective effect against necrosis and apoptosis (p<0.05) in the NM group. CONCLUSION: NM exhibited good vascular relaxation and a reasonable anti-vasocontraction effect with a better cell protecting effect than papaverine; therefore, we concluded that NM is a good potential conduit preserving agent.

Chitosan/PVA nerve conduits repair sciatic nerve defect in rats / 中华显微外科杂志

ObjectiveTo investigate the effects of chitosan/PVA nerve conduits which used for repairing sciatics nerve defect in rats.MethodsTwenty-seven rats were divided into 3 groups randomly,with 9 rats in each group. Firstly, the 15mm defects in the left sciatic nerves were made in the rats and were respectively repaired with chitosan/PVA conduits graft (group A), the silicon conduits graft (group B),and autografts (group C). At 12 weeks after the operations, the left sciatic nerves were taken out, and the comparative evaluation was made on the repairing effects by wet weight of gastrocnemius and soleus muscles, histological examination,computerized imaging analysis and True Blue retrograde tracing. ResultsThe wet weight of gastrocnemius and soleus muscles showed no significant difference between the chitosan/PVA graft and autograft groups (P ＞ 0.05). The wet weight of gastrocnemius and soleus muscles in significant difference between the chitosan/PVA graft and the silicon group at 12 weeks after the operation(P ＜ 0.05). The nerve fiber density showed no statistically significant differences between the chitosan/PVA and autograft groups(P＞ 0.05).The regenerative nerve fiber in group B had normal morphological and structural characters under transmission electron microscope.True Blue-labeled neuron cell bodies were found within both anterior horn of gray matter in the spinal cord and dorsal root ganglions (DRGs) ipsilateral to the operated side of the tested rats on illumination with ultra-violet light 1 week after the injection of True Blue.Conclusion Chitosan/PVA nerve conduit can effectively promote the nerve regeneration and myelinization of rat sciatic nerve, which is expected to substitute for autograft to repair nerve defects succesfully.

Comparison of Different Methods of Aortic Valve Conduit Xenograft Preservation in an Animal Experiment Model; Fresh Cryopreservation versus Acellularized Cryopreservation / 대한흉부외과학회지

BACKGROUND: The commercially used vascular xenografts have some problems such as calcification, fibrosis and tissue degeneration that are associated with inflammatory and immunologic reactions. We compared two methods of xenograft preservation (fresh cryopreservation versus acellularized cryopreservation) of goat aorta. MATERIAL AND METHOD: Aortic valved xenografts were harvested from adult pigs, and these were preserved using fresh cryopreservation (FC group, n=4) or acellularized crypreservation (AC group, n=4). These xenografts were implanted into adult goats. There were 2 short-term survivors (less than 100 days) and 2 long-term survivors in each group. These xenografts were explanted and they underwent microscopic examination. RESULT: The goats survived 31, 40, 107 and 411 days in the FC group and the other goats survived 5, 40, 363 and 636 days in the AC group. All the short-term survivors in each group expired because of rupture at the proximal anastomosis site. Marked neutrophil infiltration was observed in the FC group FC and lymphocytes were observed in the AC group. There were no differences in the occurrence of calcification, fibrosis and thrombosis among the groups. CONCLUSION: Some goats survived more than 100 days after the xenograft implantation irrespective of the methods of preservation. Because severe tissue degeneration developed in both groups, we think these methods are not appropriate for xenograft preservation of aorta. It was worth a preliminary trial for improving the preservation method or to modify the processing of xenografts.

Deep Vein as a Graft Conduit: 2 case reports / 대한흉부외과학회지

The ideal graft requires acceptable size, less tissue toxicity, resistance to infection, and long-term durability. Great saphenous veins are gaining popularity as acceptable graft conduits, but they require time to grow in caliber. We report 2 cases of graft bypass and reconstruction using superficial femoral veins to acheive immediate high-flow patency.

Histomorphological Comparison of the Coronary Artery and Available Graft Conduits / 대한흉부외과학회지

BACKGROUND: The histomorphological properties of the left anterior desecending artery (LAD), the left internal thoracic arteries (LITA), the radial arteries (RA) and the intercostal arteries (ICA) were studied for their use as a conduit for coronary artery bypass grafting (CABG), and we compared them with each other. MATERIAL AND METHOD: All the vessels were harvested from nineteen cadavers (17 males and 2 females). The mid-portion of the LAD, the mid-portion of the LITA, the distal RA and the mid-portion of the 5th ICA were obtained. All of them were stained with hematoxylin-eosin and with Van Gieson's elastin stain. The morphological characteristics were examined and the thicknesses of the intima and media (I/M ratio: the intima to media ratio) were compared using one-way ANOVA tests. RESULT: The mean age of the cadavers was 61.5+/-9.6 years. The LITA and ICA were elastic arteries, and the LAD and RA were muscular arteries. The I/M ratio showed statistically significant differences: 0.07+/-0.03 in the LITA, 0.16+/-0.11 in the ICA, 0.45+/-0.29 in the RA and 0.93+/-0.52 in the LAD, respectively. CONCLUSION: This study showed that the degrees of intimal hyperplasia of the CA and the various conduits for CABG were different significantly. The ICA was found to have relatively favorable characteristics as a coronary bypass conduit, but its suitability for clinical use is a challenging issue.

Twenty-one Year Experience with Right Ventricle to Pulmonary Artery Conduit Interposition / 대한흉부외과학회지

BACKGROUND: The aim of this study is to evaluate the long term results of creating various right ventricle to pulmonary artery conduits for treating complex congenital heart disease. MATERIAL AND METHOD: Between June 1986 and July 2006, we retrospectively reviewed 245 patients who underwent reconstruction of the right ventricular outflow tract with various kinds of conduits. 410 operations were done in 245 patients, the mean age at operation was 3.2+/-4.9 years (range: 7 days~45 years) and the mean body weight was 12.5+/-8.7 kg (range: 2.4~76.3 kg). RESULT: We used the following conduits: Polystan conduit, Shelhigh conduit, Carpenter-Edward conduit, Dacron graft with an artificial valve, valveless Gore Tex vascular graft, homograft and hand-made bovine or autologous pericardial conduit. The mean follow up duration was 6.3+/-5.2 years. Redo operation for RV-PA conduit dysfunction was performed in 131 patients, a second redo was done in 31 and a third redo was done in 3. The reoperation free rates were 67.3%, 48.5% and 39.4% for 5 years, 10 years and 15 years, respectively. The homograft showed the best durability, followed by the Dacron graft with artificial valve and the Carpentier-Edward conduit. The larger sized conduit showed better durability. CONCLUSION: The homograft showed lowest reoperation rate and a smaller size of conduit showed the highest reoperation rate. The reoperation rate for the RV-PA conduit was about 35% at 5 years, so it is mandatory to develop the more durable conduit for RV outflow.

Serum Lmmunoglobulin G and M Level after Xenograft Valve or Valved Conduit Implantation / 대한흉부외과학회지

BACKGROUND: The aim of this study is to confirm that peripheral blood sampling for measuring of serum immunoglobulin can predict immunological changes after xenograft implantation. MATERIAL AND METHOD: Between March 2006 and January 2007, 19 patients were enrolled (10 xenograft implantation group, 9 control group). Through 3 peripheral blood samples, we measured changes in serum immunoglobulin G and M levels preoperatively, and 2 and 10 days postoperatively. RESULT: In both groups, serum immunoglobulin levels showed similar changes-they decreased 2 days postoperatively, then increased up to the baseline levels 10 days postoperatively. However, this postoperative change of immunoglobulin G and M was not significantly different in absolute value or pattern between the 2 groups (Ig G; p-value=0.393, Ig M; p-value=0.193). CONCLUSION: We could not predict immunological changes after xenograft implantation by measuring serum immunoglobulin levels by simple blood sampling. Direct checking of alpha-Galactose antibody may confirm an immunological reaction after xenograft implantation.

Angiographic Results of Radial Artery Grafts that are Used for Myocardial Revascularization / 대한흉부외과학회지

BACKGROUND: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other grafts with retrospective manner. MATERIAL AND METHOD: From January 2001 to June 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month (2~110 month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. RESULT: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p<0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. CONCLUSION: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

Replacement of Obstructed Extracardiac Conduits with Autologous Tissue Reconstructions (Peel operation); Early and Midterm Results / 대한흉부외과학회지

BACKGROUND: Reoperation is usually required for a right ventricle to pulmonary artery conduit obstruction caused by valve degeneration, conduit peel formation or somatic growth of the patient. An autologous tissue reconstruction (peel operation), where a prosthetic roof is placed over the fibrotic tissue bed of the explanted conduit, has been used to manage conduit obstructions at our institute since May 2002. Herein, the early and midterm results are evaluated. MATERIAL AND METHOD: Between May 2002 and July 2006, 9 patients underwent obstructed extracardiac conduit replacement with an autologous tissue reconstruction, at a mean of 5.1 years after a Rastelli operation. The mean age at reoperation was 7.5+/-2.4 years, ranging from 2.9 to 10.1 years. The diagnoses included 6 pulmonary atresia with VSD, 2 truncus arteriosus and 1 transposition of the great arteries. The preoperative mean systolic gradient was 88.3+/-22.2 mmHg, ranging from 58 to 125 mmHg. The explanted conduits were all Polystan valved pulmonary conduit (Polystan, Denmark). A bioprosthetic valve was inserted in 8 patients, and a monocusp ventricular outflow patch (MVOP) was used in 1 patient. The anterior wall was constructed with a Gore-Tex patch (n=7), MVOP (n=1) and bovine pericardium (n=1). Pulmonary artery angioplasty was required in 5 patients and anterior aortopexy in 2. The mean cardiopulmonary bypass time was 154 minutes, ranging from 133 to 181 minutes; an aortic crossclamp was not performed in all patients. The mean follow-up duration was 20 months, ranging from 1 to 51 months. All patients were evaluated for their right ventricular outflow pathway using a 3-D CT scan. RESULT: There was no operative mortality or late death. The mean pressure gradient, assessed by echocardiography through the right ventricular outflow tract, was 20.4 mmHg, ranging from 0 to 29.6 mmHg, at discharge and 26 mmHg, ranging from 13 to 36 mmHg, at the latest follow-up (n=7, follow-up duration >1 year). There were no pseudoaneurysms, strictures or thrombotic occlusions. CONCLUSION: A peel operation was concluded to be a safe and effective re-operative option for an obstructed extracardiac conduit following a Rastelli operation.

Analysis of Postoperative Coronary Angiography in Symptomatic Patients / 대한흉부외과학회지

BACKGROUND: We analyzed post-operative angiography performed in symptomatic patients to evaluate the patency rates and the roles of grafts. MATERIAL AND METHOD: We reviewed 52 (15%) coronary angiograms performed for recurrent angina after prior coronary artery bypass surgery from January 1995 to June 2005. A total of 345 patients underwent coronary artery bypass surgery during this period. There were 41 men and 11 women and the mean age was 64.07+/-15.58 years. The median period from operation to re-angiogram was 68.5 months (range, 1 to 126 months). The numbers of grafts and peripheral anastomoses were 42 and 43 for internal thoracic artery (ITA), 14 and 20 for radial artery (RA), and 49 and 89 for saphenous vein. The mean number of anastomosis was 2.9 per patient. RESULT: The patency rates of ITA, RA and saphenous vein graft (SVG) were 37/43 (86%), 17/20 (85%) and 34/89 (38.2%). The patency rate of arterial grafts was significantly higher than that of SVG (p<0.001) and the patency rate of the RA was comparable to that of ITA (p=0.912). The patency rate of sequential SVGs was higher than that of single SVG (40.3% vs 31.8%, p=0.478) and the patency rate of proximal segments in sequential anastomosis was higher than that in single anastomsis (55.6% vs 31.8%, p=0.097), but statistically not significant. CONCLUSION: Arterial grafts have markedly superior patency rates than SVGs, so consideration should be given to the vigorous use of arterial grafts. The patency rate of the RA was comparable to that of ITA.

Early Result of Proximal Anastomosis Methods of Radial Artery in Coronary Artery Bypass Surgery / 대한흉부외과학회지

BACKGROUND: There are many different opinions regarding the proximal anastomotic sites of radial artery in coronary artery bypass surgery. Therefore, we compared the clinical and angiographic findings according to anastomosis of radial artery to develop a guideline. MATERIAL AND METHOD: From January 2003 to December 2004, 48 patients who underwent coronary artery bypass surgery using radial artery in Kangdong Sacred Heart Hospital were studied for clinical and coronary angiographic findings and were divided into group I for radial artery that anastomsed to aorta independently and group II that anastomosed to left internal mammary artery. RESULT: Patients in group I were 33 (men 26, women 7; mean age 61.93+/-6.56) and group II were 15 (men 13, women 2; mean age 59.53+/-6.02) and there was no difference in preoperative characteristics. Patients in group I had longer cardiopulmonary bypass time (169.36+/-40.28 versus 139.40+/-20.45, p=0.026) and patients in group II had more sequential grafts with RA per patients (5/33 versus 11/15, p <0.05). Patients in group I used more vein graft for distal anatstomosis (47/117 (40%) versus 9/48 (18%), p=0.011) and there was no difference in perioperative outcome and overall survival. Mean follow-up time was 15.87+/-7.33 (1 to 28) months in patients of the group I and 21.40+/-2.85 (17 to 25) months in group II. Postoperative coronary angiography was performed 17/33 (51.5%) in group I and 14/15 (93.3%) in group II. Early perfect patency rate was not statistically different in left anterior descending artery (15/17 (88.2%) versus 2/14 (85.7%), p=1.00) and radial artery (17/20 (85%) versus 30/30 (100%), p=0.058). Late mortality was 1/33 (3.0%) in group I and 1/15 (6.7%) in group II. CONCLUSION: There was no difference in terms of clinical and postoperative angiographic findings except in cardiopulmonary bypass time, the number of sequential grafts with the RA per patients and the number of the used vein graft.

Availability of the Skeletonized Gastroepiploic Artery as a Free Graft for Coronary Artery Bypass Grafting / 대한흉부외과학회지

BACKGROUND: To maximize the histological advantage and minimize the physiological disadvantage, we have been using the skeletonized gastroepiploic artey (GEA) as a free graft for total arterial revascularization. The aims of the current study was to assess the efficacy of the skeletonized GEA as a composite or extended graft for total arterial revascularization. MATERIAL AND METHOD: Between January 2000 and Feburary 2005, 133 patients (43 female, mean age=61.8 yrs) undergoing coronary artery bypass grafting (CABG) with a skeletonized GEA as free graft (22 extended, 107 composite and 4 others) were enrolled in this study. Coronary angiograms were performed in the immediate (median 14 days, n=86), early (median 366 days, n=56) and midterm (median 984 days, n=29) postoperative periods. RESULT: There were 3 (2.2%) early and 4 (3.3%) late cardiac-related deaths. The mean number of distal anastomoses per patient was 3.34 for total graft and 1.92 for GEA graft. The immediate, early, and midterm GEA patency were 157/159 (98.7%), 106/112 (94.6%), and 53/56 (94.6%), respectively. During follow-up, four patients required percutaneous intracoronary intervention because of GEA and target coronary artery stenosis or competitive flow. CONCLUSION: These data demonstrate satisfactory clinical and angiographic results in the skeletonized GEA as free graft for total arterial revascularization. Although we need a careful longer follow-up, the skeletonized GEA as a free graft will be a valuable option 'to be' for CABG.

Early Failure of the Shelhigh Pulmonary Valve Conduit in Ross Operation: Two case reports / 대한흉부외과학회지

It is very difficult to choose the ideal valved conduit used in right ventricle outflow reconstruction in child. We can use the cryopreserved homograft but there is a limit of appplication because of its difficulties in the size matching and supply capacity. The Shelhigh(R) porcine-valved conduit is commercially available and used as an alternative choice in these days. We report two cases of early Shelhigh conduit failure in right ventricular outflow tract after Ross operation in congenital aortic stenosis.

Total Arterial Off-Pump Coronary Revascularization with Multiple Y Arterial Composite Grafts / 대한흉부외과학회지

BACKGROUND: Complete arterial off-pump coronary artery bypass grafting (OPCAB) by sequential anastomoses with one or two arterial grafts provides favorable outcomes. However, problems of insufficient graft length, hypoperfusion, kinking of graft, and unfavorable course of graft may be encountered. To solve these problems, we have used different technique with multiple arterial Y composite graft to allow end-to-side rather than sequential anastomoses and evaluated the results of this method. MATERIAL AND METHOD: Between February 2003 and October 2004, 71 patients underwent total arterial OPCAB using multiple arterial Y composite grafts with left internal mammary artery (LIMA), radial artery (RA), and right internal mammary artery (RIMA). We divided RA into multiple segments by number of distal target site after measuring of individual proper length and constructed arterial composite graft. One of segments was sutured end-to-side to LIMA and other segment was sutured end-to-side to the previously constructed radial graft. Postoperative graft patency was evaluated in 61 patients by multi-slice computed tomography. RESULT: An average of 2.5+/-0.6 arteries and 3.7+/-0.7 distal anastomoses per patient were done. There was no perioperative myocardial infarction, clinical hypoperfusion syndromes, and operative mortality. Postoperative mean CK-MB level was 17.4+/-29.7 IU/L. Overall graft patency was 99.1% (214/216)(LIMA: 100%, RA: 98.4%, RIMA: 100%). CONCLUSION: This technique allows total arterial OPCAB without technical problems and provides excellent early clinical results and graft patency. We believe that this technique is more convenient in the obtuse marginal area compared to sequential technique, and helpful in patients who require complex arterial grafting.

Free Flow in Internal Thoracic Artery and Internal Thoracic Artery-Radial Artery Composite Graft / 대한흉부외과학회지

BACKGROUND: The Y-composite graft of internal thoracic artery and radial artery is commonly used in coronary bypass surgery. The aim of this study is to look for a way to raise the free flow of the internal thoracic graft and to see flow dynamics of the Y-graft. MATERIAL AND METHOD: In 15 patients undergoing coronary bypass surgery, free flow of the in-situ internal thoracic artery graft was measured using two different papaverine application methods; extraluminal papaverine spray in 7 patients and intraluminal papaverine injection in 8. In 18 other patients for whom the Y-graft was used, total free flow and flow changes from the two ends were measured. RESULT: The free flow of the in-situ internal thoracic artery graft almost doubled with internal papaverine injection than with external papaverine spray (47.7+/-9.6 mL/min vs. 100.8+/-26.3 mL/min, p<0.001). Total flow of the Y-composite graft was significantly more than either flow of the internal thoracic artery end or radial artery graft end (173.3+/-45.3 mL/min vs. 121.1+/-34.3 mL/min or 117.5+/-42.8 mL/min). When both ends of the Y-composite graft were opened, free flows from the two ends were similar (85.4+/-27.8 mL/min vs. 87.9+/-42.4 mL/min, p=0.772). The flow of one end of the Y-composite graft was increased significantly by clamping of the other-end than when both ends were opened. CONCLUSION: Intraluminal papaverine injection is very effective in raising free flow of the internal thoracic artery graft, and the free flow of the Y-composite graft of in-situ internal thoracic artery and free radial artery graft is more than that of the in-situ internal thoracic artery graft. The flow of one end flow of the Y-graft may be altered by the flow change of the other end.