Em J Cardio-thorac
Surg (1991) 5663-664
0 Springer-Verlag 1991
Early rupture of a saphenous vein graft R.D. Page, G. R. Dixon, and B. M. Fabri The Cardiothoracic
Centre, Liverpool,
UK
Abstract. Early rupture of a saphenous vein graft used for coronary artery surgery has not been previously reported. In a 69-year-old man having a third coronary by-pass procedure, one of the saphenous vein grafts ruptured on the 8th postoperative day. The other vein graft showed marked aneurysm formation at two sites. Histological examination of the ruptured graft revealed that this was due to a bacterial infection within the wall of the vein. Although he survived an emergency operation to control the haemorrhage and replace the ruptured graft, he died some days later of mediastinitis. It appeared that both the rupture of the graft and the ensuing mediastinitis were due to a primary infective process within the saphenous vein used for the graft. [Eur J Cardio-thorac Surg (1991) 56634641 Key words: Saphenous vein graft - Coronary
artery by-pass surgery - Aneurysm - Mediastinitis
The use of saphenous vein for coronary artery bypass surgery (CABG) is associated with remarkably few inherent short term problems. Aneurysm formation is reported rarely and usually occurs several months if not years postoperatively. We report a case of aneurysm formation of saphenous vein grafts leading to rupture of one of the grafts within the first week after surgery. Case report A 69-year-old man presented with unstable angina. He had undergone CABG using saphenous vein on two occasions, 5 and 17 years previously. The grafts had occluded, but left ventricular function was well preserved. A third operation was performed uneventfully using the left internal mammary artery which was grafted to the first diagonal branch of the left anterior descending artery (LAD). The remaining length of saphenous vein from below the left knee was grafted to the LAD itself and a branch of the circumflex artery. This vein appeared somewhat atrophic but was otherwise of good quality and of even calibre throughout its length. The mammay artery was grafted to a diagonal branch rather than the LAD itself as the former vessel was of a larger calibre and appeared to supply a wider area on coronary angiography. The LAD itself was of borderline operability. The early postoperative recovery was uneventful apart from slight gaping of the lower part of the sternotomy incision which was attributed to superficial sepsis. On day 8, there was a sudden torrential bleed from the wound and the patient collapsed with signs of cardiac tamponade. This was relieved by opening the wound on the ward, after which he was taken immediately to the operating room. Received for publication: Accepted for publication:
August 1, 1991 August 15, 1991
The vein graft to the LAD was bleeding from a longitudinal rupture over a length of 2 cm causing a tamponade. The mediastinum showed early signs of sepsis and the vein graft to the circumflex artery had a 1 cm aneurysm in its mid portion. A piece of cephalic vein was used to re-graft the LAD. The aneurysmal vein graft to the circumflex artery was left in place as it was patent and appeared to be functioning adequately. The patient did well initially, but developed further mediastinal sepsis and died 13 days after the second procedure. Histological examination of the ruptured graft (Fig. 1) revelaed the endothelium to be largely replaced by a librinopurulent slough. A mixed inflam-
Fig. 1. A section through the site of rupture showing necrosis of the media and disruption of elastic Iibres by a mixed inflammatory cell infiltrate (arrow). L = Lumen. Inset: gram positive cocci within the graft at the site of rupture
664 matory cell infiltrate disruption of elastic Gram positive cocci the wall of the graft
was present within the media and there was fibres, especially at the edges of the rupture. were identified throughout the full thickness of (Inset).
Discussion True aneurysm formation within a saphenous vein used for CABG is rare although well recognised [3]. Atherosclerosis of the grafts and hyperlipidaemia are thought to be responsible. Rupture of these aneurysms has only been occasionally reported [l ,2]. These cases all occurred several months after surgery and the rupture was well contained by pericardial adhesions enabling definitive treatment to be carried out. We can find no reports of early rupture in the literature. An atrophic saphenous vein as seen in this patient is not unusual. When the portion of vein within the thigh has been removed (as in this patient, for a previous CABG), the remaining distal portion is often rather thinwalled and small, providing the valves controlling communications with the deep venous system are competent. However, rupture of thin-walled saphenous vein grafts is not a recognised complication of CABG. Aneurysm formation in blood vessels due to infection is a well recognised phenomenon (the so-called mycotic aneurysm). It is due to the infective process causing disruption of tissues within the media of vessels resulting in weakening, dilatation and possible rupture. The aneurysm formation which occurred in both grafts in this patient appeared, on histological evidence, to be due to
infection with the saphenous vein itself. This may have been present when the vein was harvested although it was not recognised at the time. Alternatively, it may have occurred soon after surgery secondary to a transient bacteraemia. The saphenous vein loses its blood supply from its vasa vasorum soon after harvesting and “dies”. Secondary infection of a saphenous vein graft is therefore a possibility, although we are unaware of any previous reports. Septic phlebitis of the graft, whether preexisting or occurring postoperatively, would certainly explain the development of the fatal mediastinitis as well as the aneurysm formation.
References Nielson JF, Stentoft J, Aunsholt NA (1988) Hemoptysis caused by aneurysm of saphenous vein graft to a coronary artery. Stand J Cardiovasc Surg 22: 189-191 Shapeero LG, Guthaner DF, Swerdlow CD, Wexler L (1983) Rupture of coronary bypass aneurysm: CT evaluation and coil occlusion therapy. A J R 141: 1060-1062 Teja K, Dillingham R, Mentzer RM (1987) Saphenous vein aneurysms after aortocoronary bypass grafting: Postoperative interval and hyperlipidaemia as determining factors. Am Heart J 113: 1527-1529
Mr. Brian M. Fabri, FRCS The Cardiothoracic Centre Thomas Drive Liverpool L14 3PE United Kingdom
Surg (1991) 5663-664
0 Springer-Verlag 1991
Early rupture of a saphenous vein graft R.D. Page, G. R. Dixon, and B. M. Fabri The Cardiothoracic
Centre, Liverpool,
UK
Abstract. Early rupture of a saphenous vein graft used for coronary artery surgery has not been previously reported. In a 69-year-old man having a third coronary by-pass procedure, one of the saphenous vein grafts ruptured on the 8th postoperative day. The other vein graft showed marked aneurysm formation at two sites. Histological examination of the ruptured graft revealed that this was due to a bacterial infection within the wall of the vein. Although he survived an emergency operation to control the haemorrhage and replace the ruptured graft, he died some days later of mediastinitis. It appeared that both the rupture of the graft and the ensuing mediastinitis were due to a primary infective process within the saphenous vein used for the graft. [Eur J Cardio-thorac Surg (1991) 56634641 Key words: Saphenous vein graft - Coronary
artery by-pass surgery - Aneurysm - Mediastinitis
The use of saphenous vein for coronary artery bypass surgery (CABG) is associated with remarkably few inherent short term problems. Aneurysm formation is reported rarely and usually occurs several months if not years postoperatively. We report a case of aneurysm formation of saphenous vein grafts leading to rupture of one of the grafts within the first week after surgery. Case report A 69-year-old man presented with unstable angina. He had undergone CABG using saphenous vein on two occasions, 5 and 17 years previously. The grafts had occluded, but left ventricular function was well preserved. A third operation was performed uneventfully using the left internal mammary artery which was grafted to the first diagonal branch of the left anterior descending artery (LAD). The remaining length of saphenous vein from below the left knee was grafted to the LAD itself and a branch of the circumflex artery. This vein appeared somewhat atrophic but was otherwise of good quality and of even calibre throughout its length. The mammay artery was grafted to a diagonal branch rather than the LAD itself as the former vessel was of a larger calibre and appeared to supply a wider area on coronary angiography. The LAD itself was of borderline operability. The early postoperative recovery was uneventful apart from slight gaping of the lower part of the sternotomy incision which was attributed to superficial sepsis. On day 8, there was a sudden torrential bleed from the wound and the patient collapsed with signs of cardiac tamponade. This was relieved by opening the wound on the ward, after which he was taken immediately to the operating room. Received for publication: Accepted for publication:
August 1, 1991 August 15, 1991
The vein graft to the LAD was bleeding from a longitudinal rupture over a length of 2 cm causing a tamponade. The mediastinum showed early signs of sepsis and the vein graft to the circumflex artery had a 1 cm aneurysm in its mid portion. A piece of cephalic vein was used to re-graft the LAD. The aneurysmal vein graft to the circumflex artery was left in place as it was patent and appeared to be functioning adequately. The patient did well initially, but developed further mediastinal sepsis and died 13 days after the second procedure. Histological examination of the ruptured graft (Fig. 1) revelaed the endothelium to be largely replaced by a librinopurulent slough. A mixed inflam-
Fig. 1. A section through the site of rupture showing necrosis of the media and disruption of elastic Iibres by a mixed inflammatory cell infiltrate (arrow). L = Lumen. Inset: gram positive cocci within the graft at the site of rupture
664 matory cell infiltrate disruption of elastic Gram positive cocci the wall of the graft
was present within the media and there was fibres, especially at the edges of the rupture. were identified throughout the full thickness of (Inset).
Discussion True aneurysm formation within a saphenous vein used for CABG is rare although well recognised [3]. Atherosclerosis of the grafts and hyperlipidaemia are thought to be responsible. Rupture of these aneurysms has only been occasionally reported [l ,2]. These cases all occurred several months after surgery and the rupture was well contained by pericardial adhesions enabling definitive treatment to be carried out. We can find no reports of early rupture in the literature. An atrophic saphenous vein as seen in this patient is not unusual. When the portion of vein within the thigh has been removed (as in this patient, for a previous CABG), the remaining distal portion is often rather thinwalled and small, providing the valves controlling communications with the deep venous system are competent. However, rupture of thin-walled saphenous vein grafts is not a recognised complication of CABG. Aneurysm formation in blood vessels due to infection is a well recognised phenomenon (the so-called mycotic aneurysm). It is due to the infective process causing disruption of tissues within the media of vessels resulting in weakening, dilatation and possible rupture. The aneurysm formation which occurred in both grafts in this patient appeared, on histological evidence, to be due to
infection with the saphenous vein itself. This may have been present when the vein was harvested although it was not recognised at the time. Alternatively, it may have occurred soon after surgery secondary to a transient bacteraemia. The saphenous vein loses its blood supply from its vasa vasorum soon after harvesting and “dies”. Secondary infection of a saphenous vein graft is therefore a possibility, although we are unaware of any previous reports. Septic phlebitis of the graft, whether preexisting or occurring postoperatively, would certainly explain the development of the fatal mediastinitis as well as the aneurysm formation.
References Nielson JF, Stentoft J, Aunsholt NA (1988) Hemoptysis caused by aneurysm of saphenous vein graft to a coronary artery. Stand J Cardiovasc Surg 22: 189-191 Shapeero LG, Guthaner DF, Swerdlow CD, Wexler L (1983) Rupture of coronary bypass aneurysm: CT evaluation and coil occlusion therapy. A J R 141: 1060-1062 Teja K, Dillingham R, Mentzer RM (1987) Saphenous vein aneurysms after aortocoronary bypass grafting: Postoperative interval and hyperlipidaemia as determining factors. Am Heart J 113: 1527-1529
Mr. Brian M. Fabri, FRCS The Cardiothoracic Centre Thomas Drive Liverpool L14 3PE United Kingdom
