Aarno Lehtola

Right gastroepiploic artery as a coronary bypass graft

Between November 1987 and April 1988, the right gastroepiploic artery (GEA) was used as a coronary artery bypass graft in 11 patients, 9 men and 2 women. In 1 of them, the GEA was used because no veins were available; in the others, the GEA was used to avoid the use of vein grafts. The GEA was anastomosed to the right coronary artery in all patients, and internal mammary artery grafts were used to bypass the left anterior descending and circumflex coronary arteries. All patients survived the operation. There were no early and, to date, there have been no late complications of the abdominal component of the operation. Postoperative coronary angiography showed a patent right GEA in 9 patients (82%). In 1 patient the GEA was occluded, probably because of an enlarged liver. If the long-term patency of right GEA grafts is similar to that of internal mammary artery grafts, wider use of this viable graft is indicated.

Single lung allotransplantation in pigs : a morphologic study of tissue preservation with modified euro-collins and fluorocarbon solutions

In the present study the functional and morphologic effects of two pulmoplegic solutions are evaluated. Single left-lung allotransplantation with ligation of the right pulmonary artery was performed in 15 piglets (13-20 kg). The lungs were preserved after donor prostaglandin E-1 treatment with single pulmonary artery flush with either modified Euro-Collins solution (mECS) (9 pigs) or oxygenated fluorocarbon emulsion (FC-43) (6 pigs) and transplanted after 6-hr storage in cold Physiosol solution. Tidal volumes of 15 ml/kg x fr (18) with 40% inspired oxygen were used for ventilation during reperfusion. Function of the transplanted lung was monitored for 4 hr postoperatively by determining pa CO2 and pa O2 levels from arterial samples and by noninvasive monitoring of end-tidal CO2 values and arterial oxygen saturations. Sequential morphologic changes in pulmonary artery flow surface and lung tissue were studied after 6-hr storage and 4-hr reperfusion, using light, scanning, and transmission electron microscopy (LM, SEM, TEM). There was no mortality. After transplantation the mECS group experienced significant hypoxia and hypercarbia and had low end-tidal CO2 values as signs of defective oxygenation and gas exchange, whereas the FC-43 group was normoxic and normoventilated without disturbed elimination of carbon dioxide. After storage and reperfusion, LM showed signs of increased vascular permeability and reperfusion damage--more evident in the mECS group compared with the FC-43 group--while the lymphoid cell population was more intensely activated in the latter group. Electron microscopy after storage showed good overall preservation of structures in both groups. After reperfusion preservation of pulmonary artery flow surface and lung tissue was estimated to be moderate in the mECS group, whereas it was good-to-moderate in the FC-43 group by SEM (NS). TEM of lung tissue, however, showed significantly better-preserved alveolar epithelial lining in the FC-43 group compared with the mECS group. In conclusion, oxygenated fluorocarbon (FC-43) pulmoplegia gave better functional and morphologic preservation of lung grafts compared with modified Euro-Collins solution.

Long-term results of vein sparing varicose vein surgery

The aim of this study was to assess the long-term functional outcome of vein sparing varicose vein surgery using handheld Doppler ultrasound (HHD). The series consisted of 171 consecutive day-case surgery patients operated on for uncomplicated lower limb varicose veins. Venous segments considered competent were spared based on clinical examination and HHD, which was performed preoperatively only when deemed necessary by the surgeon. After a mean follow-up of 8 years all patients were examined, a systematic HHD evaluation was performed, and the findings were classified according to the CEAP (Clinical, Etiological, Anatomical, Pathophysiological) classification, and disability scoring was performed. During the follow-up period 17% of the legs were reoperated or scheduled for reoperation. At follow-up 79% of all patients were asymptomatic without reoperation. In 24%, recurrent varicosities were present and venous reflux was demonstrated by HHD. Recurrence was two times more common when the saphenofemoral junction had originally been left intact. Of all recurrent cases, reflux was demonstrated in the long saphenous vein (LSV) above the knee in 62%, in the LSV below the knee in 7%, in the short saphenous vein (SSV) in 16%, in the posterior arch vein in 38%, and in a thigh perforator in 8%. Of the legs reoperated during the follow-up period 41% presented with venous reflux at the follow-up visit. We conclude that HHD efficiently reveals sites of reflux that have been missed during previous surgery and that a thorough preoperative HHD examination and marking of reflux routes is required.RésuméLe but de cette étude a été d’évaluer l’évolution fonctionnelle à long terme de la chirurgie conservatrice pour varices des membres inférieurs en utilisant un appareil écho doppler (ED) tenu à la main. Notre série a consisté en 171 patients consécutifs traités en ambulatoire pour varices des membres inférieurs non compliquées. Tout segment de veine considéré comme compétant a été épargné, basé sur les données de l’examen clinique et l’ED, qui a été réalisée en préopératoire lorsque le chirurgien l’a estimé nécessaire. Après un suivi moyen de huit ans, tous les patients ont été examinés, une évaluation systématique par ED a été réalisée et les résultats ont été classés selon la classification «CEAP» et la classification de handicap physique. Pendant le suivi, une réopération a été effectuée ou programmée pour 17% des jambes. Au suivi, 79% de tous les patients étaient asymptomatiques sans réopération. Chez 24%, on a trouvé des varicosités récidivantes et on a mis en évidence un reflux veineux par l’ED. La récidive a été deux fois plus fréquente lorsque l’on a laissé intacte initialement la jonction saphéno-fémorale. Dans tous les cas de récidives, on a mis en évidence un reflux dans la saphène majeure (SMa) (interne) au-dessus du genou dans 62% des cas, dans la SMa en dessous du genou dans 7%, dans la saphène mineure (Smi) (externe) chez 16%, dans la communicante veineuse postérieure chez 38%, et dans une perforante de la cuisse dans 8%. 41% des jambes réopérés dans la période de suivi ont eu un reflux veineux lors de la visite de contrôle. Nous concluons que TED décèle effectivement les sites de reflux qui ont été méconnus lors de l’acte chirurgical antérieur et qu’un examen ED préopératoire complet avec marquages des veines de reflux est nécessaire.ResumenEl objectivo de este estudio fue averiguar los resultados funcionales tardios, mediante ecoangiografia Doppler (HHD), del tratamiento quirûrgico controlado (conservador) de las varices. Nuestra casuistica comprende 171 pacientes con varices simples del miembro inferior, intervenidas ambulatoriamente. Los segmentos venosos considerados compétentes, tanto por la exploración clínica corno mediante el HHD preoperatorio (si tal prueba diagnóstica era requerida por el cirujano) se respetaron. Tras un seguimiento medio de 8 años, todos los pacientes fueron reexplorados, se realizó además, una evaluación sistemática con el HHD y los resultados se expresaron de acuerdo con la clasificación CEAP y en relación a su grado de incapacidad. Durante el periodo de seguimiento el 17% de los casos fueron reintervinieron o estaban programados para una reoperación. Al finalizar el seguimiento, el 79% de todos los pacientes no habían requerido reopersción alguna y estaban asintomäticos. En el 24% había recidiva varicosa, con reflujo venoso demostrado mediante el HHD. Las récidivas se duplicaron cuando en la operación inicial se habÌa respetado la conjunción safeno-femoral. En todas las récidivas se constatò reflujo en la vena safena interna (LSV): por encima de la rodilla en el 62% y por debajo en el 7%; se registrò reflujo en la safena externa en el 16%, en el arco venoso posterior en el 38% y en las perforantes del muslo en el 8% de los casos. El 41% de los miembros reintervenidos durante el periodo de seguimiento presentaban, ya en la primera visita, reflujo venoso. El HHD muestra claramente los puntos de reflujo que pasaron desapercibidos durante la intervención quirúrgica inicial. Por consigliente, es preciso realizar, en todos los casos, un HHD preoperatorio para demarcar todas las posibles rutas de reflujo.

Single-Lung Allotransplantation in Pigs Following Donor Pretreatment with Intravenous Prostaglandin E-1: Morphologic Changes after Preservation and Reperfusion

Single left lung allotransplantation with ligation of the right pulmonary artery was performed on 11 pigs after donor pretreatment with prostaglandin E-1 and pulmonary artery flush with modified Euro-Collins solution. Sequential morphologic changes in pulmonary artery flow surface and lung structure were studied after 6-hour storage and after 4-hour reperfusion, using light microscopy and scanning and transmission electron microscopy. Morphologic observations were compared with functional changes. After 6-hour preservation slight degenerative changes were found in the pulmonary artery flow surface and changes in lung tissue suggestive of increased vascular permeability and edema. During 4-hour reperfusion the changes progressed. Preservation was in general moderate. Lung tissue showed vascular congestion and slight inflammation. Localized areas of reperfusion damage could adjoin near-normal looking alveoli. Oxygenation and gas exchange, though low in the beginning of reperfusion, tended to improve during the reperfusion period. The method was concluded to afford good morphologic preservation of the graft after 6-hour storage, and moderately good morphologic and functional preservation after 4-hour reperfusion.

Intracellular-type solution flush for preservation of myocardium and coronary and pulmonary artery flow surface

Modified Euro-Collins solution (ECS), which has been successfully used in kidney, liver and lung transplantation, was tested concerning myocardial and endothelial preservation in nine piglets. In six (group I), 1-hour cardiac arrest was induced with cold modified ECS, and in three (group II) heart-lung transplantation was performed, using modified ECS for graft preservation. In group I myocardial energy preservation was determined with biochemical assays for adenosine triphosphate, creatine phosphate, lactate and creatine 5, 15, 30 and 60 minutes after aortic clamping, and preservation of endothelium in the aorta and coronary arteries was studied with scanning electron microscopy. In group II electron microscopy was performed on endothelial samples from the ascending aorta and coronary and pulmonary arteries of the heart-lung block after excision, after 2 hours of ischemia, and after 1-2 hours of reperfusion. High-energy phosphates decreased progressively during the ECS cardioplegia in group I, and circulatory support was required during the post-transplantation reperfusion period in group II. The endothelial lining in all specimens was remarkably well preserved, however. Modified ECS flush thus was ideal for vascular endothelium but, because of its poor energy-preserving capacity, unsuitable for cardioplegia.

Experimental piglet lung transplantation: Histological bioptic changes and autopsy findings

To investigate difficulties in diagnosing pulmonary rejection and to create a new model to observe long‐term histological consequences, 21 piglets were subjected to left single lung transplantation. Five of these transplants served as targets for unmodified rejection in piglets without immunosuppression (Group I), 13 recipients were treated with cyclosporin A, azathioprine and methylprednisolone (Group II), and in 3 cases reimplantation of an autograft was performed (Group III). In the course of postoperative graft monitoring, transthoracic/bronchial biopsies were obtained on days 3, 5, 7, 10, 14, and 20, and thereafter less frequently up to 134 days. In the unmodified rejection group, grafts consolidated in one week and histologically presented perivascular mononuclear cell infiltrates, except for one case which showed vasculitis. Lymphocytic bronchiolitis and or peribronchiolar infiltrate was present in three of the four autopsied grafts. In Group II acute rejection was detected six times in three piglets, and all except one of these specimens had a peribronchiolar component. Although no incontestable bronchiolitis obliterans developed, mild to moderate chronic obliterative vascular lesions were detected in all immunosuppressed piglets (n=3) surviving more than 80 days. Contralateral lungs and Group III autografts showed mild changes related to the operation itself and interstitial swine endemic pneumonia (SEP). Chronic changes related to rejection were limited to the vascular wall. The mainly inflammatory bronchiolar changes are thought to present an incipient phase leading to obliterative lesions.

Laser for Harvesting of the Internal Mammary Artery

In 12 piglets both internal mammary arteries were dissected from the thoracic wall without a surrounding pedicle, using low-current electrocautery for one artery and continuous wave contact Nd:YAG laser (12 W) for the contralateral vessel. Changes in the arterial flow surface were evaluated by scanning electron microscopy immediately after dissection and 2 and 5 days postoperatively. Laser dissection was easier, more accurate and as fast as electrocautery. Moderate to severe degenerative changes and endothelial desquamation were seen in the electrocautery group after dissection, but lesser changes in the laser group. The changes decreased within the next 5 days, but two electrocauterized vessels showed thrombosis at 5 days. Stripping of the internal mammary artery with either method requires great care, and Nd:YAG laser offers a promising alternative to electrocautery in harvesting of that artery as a pedicled graft.

The possibility of using celiac trunk branches as coronary artery bypass grafts

The internal mammary artery has proved to be superior to the saphenous vein for coronary artery bypass grafting, because of its arterial nature and closer approximation in size to the coronary arteries. But the internal mammary artery cannot reach the posterior surface of the heart as a pedicled graft. Two suitable intra-abdominal grafts can reach that surface, viz. the right gastroepiploic artery and the splenic artery. In experiments on eight dogs (weight 9-13.5 kg), the gastroepiploic artery was found to be too small for coronary artery anastomosis, and therefore the splenic artery was used. The size approximation with coronary artery (diameter less than 1 mm) was good. Four dogs survived the month of the study. In two of them the anastomosis was patent, in another the splenic artery was patent despite occlusion of the anastomosis, and in the fourth dog both anastomosis and graft were thrombosed. The possibility of using visceral arterial grafts in coronary surgery is discussed.

Free Internal Mammary Artery as Canine Coronary Artery Bypass Graft

From 8 dogs both internal mam mary arteries (IMA) were harvested: the right IMA as a naked artery with out surrounding tissue and the left IMA with 2-cm-wide surrounding tis sue. Both free IMA grafts were anas tomosed to the proximal end of the left IMA one after another and then to the left anterior descending coro nary artery. At six months the free IMA grafts were harvested and stud ied by light microscopy and scanning electron microscopy (SEM). Six dogs lived the period of six months and all free IMA grafts were patent at that time. In the histologic study 3 grafts were graded as normal and intimal thickening was seen in 8 cases. The endothelial cells were covering the lu minal surface of every free IMA graft in SEM, although some degeneration was seen. This study showed that free IMA grafts maintain their patency well and the method of the dissection of the IMAs did not have any effect on the results.

Polydioxanone and Polypropylene Suture Materials in Experimental Coronary Artery Surgery with Free Internal Mammary Artery

Some experimental and clinical reports have shown the feasibility of the use of polydioxanone in vascular surgery. In this study polydioxanone and polypropylene suture materials were used in free internal mammary artery (IMA) graft anastomoses, which were made in 8 dogs from the left IMA to the left anterior descend ing coronary artery one free graft af ter another. Nine polydioxanone and nine polypropylene anastomoses were studied at six months with light mi pylene anastomoses, in which the su ture material was seen bulging up from the flow surface. According to this experimental study polydiox anone is as reliable as polypropylene and has some superior features over polypropylene in small luminal vas cular anastomoses.