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Eur J Cardiothorac Surg 2005;27:821-825
© 2005 Elsevier Science NL
Department of Cardio-Thoracic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-8550, Japan
Received 2 November 2004; received in revised form 24 January 2005; accepted 25 January 2005.
* Corresponding author. Tel.: +81 52 744 2376; fax: +81 52 744 2383. (E-mail: ausui{at}med.nagoya-u.ac.jp).
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Abstract |
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 Top Abstract 1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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Key Words: Aortic arch • Survival analysis • Retrograde perfusion • Quality of life • Cerebral protection
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1. Introduction |
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TopAbstract1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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2. Materials and methods |
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TopAbstract1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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From 1998 to 2003 there were 50 consecutive cases who underwent the modified arch first technique by a single surgeon. Of these, 38 were male and 12 female, with an average age of 68 years ranging from 42 to 82 years. There were 33 true aneurysms, and 10 chronic and seven acute Stanford type A dissections. Twelve cases were operated on as emergencies. Concomitant procedures were aorto-coronary bypass grafting in four, Bentall operation [11] in two, and each of aortic valve replacement, aortic valve repair, Yacoub's procedure [12], and open distal stent grafting in a single patient. There were three cases of repeat surgery; the previous surgery was aortic valve replacement in two and ascending aortic replacement in one.
In the first 19 cases, the arch vessels were reconstructed with a hand made neoarch graft, and in the later 31 with a commercially available four branched graft (Hemashield, Boston Science Co.)
There were another 24 cases who underwent total arch replacement to reconstruct the arch vessels using the conventional distal first technique, operated on by the same surgeon from 1992 to 1998. The arch and arch vessels were replaced with a four branched graft by performing distal anastomosis, with the descending aorta first and then reconstructing the arch vessels under hypothermic circulatory arrest with retrograde cerebral perfusion.
These 24 cases comprised 14 males and 10 females, with an average age of 68 years. There were 16 true aneurysms and three chronic and five acute aortic dissections. Emergency operations for aortic dissection or aneurismal rupture were performed in 10 cases.
The groups were compared by means of the chi-square test and non-paired t-test, using the StatView J5.0 software package. A probability <0.05 was taken as significant.
2.2. Operative procedure for the arch first technique
Mitazolam (0.05mg/kg) was given intramuscularly as a premedication. Anesthesia was induced by means of an intravenous injection of Mitazolam (0.1mg/kg), Fentanyl citrate (10mg/kg) and Vecuronium bromide (0.1mg/kg), and was maintained with Fentanyl citrate (1–4mg/kg/h) and Vecuronium bromide (2mg/h) until the end of surgery, with or without Sevoflurane inhalation.
The patient was placed in the spine position and the aortic arch was exposed via a median sternotomy. Cardiopulmonary bypass was applied with bicaval drainage, and the ascending aorta was perfused after carefully inspection with direct echocardiography. Core cooling was initiated, with left ventricular venting. The aortic arch was touched as little as possible to minimize the release of debris prior to initiation of circulatory arrest. Barbital sodium (500mg) and 20% mannitol (150ml) was administered when the esophageal temperature had fallen to 22°C. Perfusion was discontinued once the esophageal temperature fell below 20°C. An anesthetic-depth monitor (BIS monitor A-1050, Aspect Medical Systems Inc., MA), which is essentially a simplified EEG, is useful to monitor brain activity. Once this monitor shows a nearly flat level of EEG activity, circulatory arrest should be established. Cross clamping was applied to the ascending aorta just distal of the perfusion cannulae, and cold blood cardioplegia was given through the perfusion cannulae. The arch vessels were transected at their orifice, and each vessel was reconstructed with a four branched arch graft (Hemashield, Boston Science, Co.) with a 4-0 polypropylene running suture in the following sequence: left subclavian artery, left carotid artery, and brachiocephalic artery. Retrograde cerebral perfusion (RCP) was applied via the superior vena cava (SVC) cannulae snared with an umbilical tape after reconstructing the left subclavian artery. The SVC pressure was maintained at approximately 10–15mmHg, with 250–350ml/min of flow rate without drainage from the inferior vena cava cannulae. The blood temperature was held at around 16–18°. After anastomosis of the arch vessels, the flow rate of RCP was increased to 700–800ml/min to complete deairing and flush debris; the RCP was then stopped and antegrade cerebral perfusion was resumed through the four branched arch graft, with clamping at both ends. The perfusion flow was maintained at 10–15ml/kg/min so that the left radial artery pressure was above 30mmHg (Fig. 1).
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3. Results |
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TopAbstract1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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All but 2 patients awoke within 24h of completion of the operation, with an average delay of 9.3±9.9h. Half of the patients were extubated within 24h, though the average intubated period was nearly 2 days. Forty percent of patients remained in the ICU for just 1 day, but the average ICU stay exceeded 3 days. In 10 cases (20%) no blood transfusion was required. There was no surgical mortality, but one patient died as a result of residual descending aortic aneurysm rupture at 3 weeks after surgery. Reversible ischemic neurological deficit (RIND) was complicated during the operation in three cases (6%), but no stroke occurred. Another two cases suffered stroke on the 3rd and 10th postoperative days. Temporary psychiatric disorder, such as delirium, was observed in a further five cases (10%). Other morbidities were: re-sternotomy for bleeding in four, low output syndrome requiring high dose inotoropic support in two, and renal dysfunction showing over 3.0mg/dl of blood creatine level in four.
All patients (except the one who died in hospital) were discharged without nursing care after an average hospital stay of 46 days following surgery.
There were five late deaths, as a result of stroke in 3 patients, pneumonia in one and residual aneurismal rupture in one. The 1 and 3 year survival rates were, respectively, 90.8 and 84.5% on an average follow-up period of 20 months (Fig. 2). Seventy three percentage of patients have no social disability, but there was slight social disability in nine and severe social disability in four patients (Table 1).
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Two patients did not awaken, and 3 patients suffered delayed awakening. There were no significant differences between the two techniques in the average awakening period (24h) or average intubation period (40h), but the distal first technique led to a significantly longer stay in ICU (7.7 days) and in hospital after surgery (77 days). All patients in the distal first technique required blood transfusion.
There were three hospital deaths (12.5%). The cause of death was bleeding in one, stroke in one and renal failure in one. Stroke was complicated in 5 patients, of whom four showed neurological sequela. Delirium occurred in four cases. Other morbidities were: re-sternotomy for bleeding in four, low output syndrome requiring high dose inotoropic support in three, and renal dysfunction with over 3.0mg/dl of blood creatinine level in three. Relative to the distal first technique, the arch first technique gave a significantly lower intra-operative stroke rate (P=0.0030) and reduced hospital mortality (P=0.0615). There were six late deaths, of whom three died within one year of surgery. The 1, 2 and 3 year survival rates were, respectively, 72.7, 63.6 and 59.1%, which are lower than for the arch first technique although the difference is not statistically significant (P=0.0692, Fig. 2).
The quality of life in the 15 survivors was as follows: no social disability in eight, slight disability in two, severe disability in three, and two cases confirmed at their homes.
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4. Discussion |
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TopAbstract1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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Since this is not a randomized study, there could be bias in the present inferences. First, the distal-first technique was performed in the early period of the study. Even in a single surgical team there is a learning curve. Minor modifications were employed even in the arch-first technique, with the aim of improving the clinical outcome. Second, the proportion of emergency operations is higher in the distal first technique. This may influence the early clinical outcome, since mortality and morbidity are always several times greater for emergency operations (Table 2).
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Is selective cerebral perfusion better than retrograde cerebral perfusion, since it is antegrade perfusion and maintains physiological circulation? Our patients show no difference in mortality or neurological outcome [5], but Okita [18] has reported a high incidence of delirium after retrograde cerebral perfusion. However, selective cerebral perfusion leads to the possibility of thrombo-embolism, since selective cannula may release debris from the clamping or snaring arch vessels, and may cause arterial injury. In the arch first technique, the aortic arch and arch vessels are scarcely touched, so that there is little chance of embolic complication. The arch first technique can, in fact, be classified as a selective cerebral perfusion, since antegrade cerebral perfusion is resumed through a branched arch graft which anastomoses each cervical vessel corresponding to a selective cannula. The arch first technique reduces the chances of releasing debris or arterial injury during selective cerebral perfusion, and this is the main advantage of our technique. However, the arch first technique made no contribution to the delirium rate in this study; one cause of delirium is thought to result from cerebral ischemic damage during retrograde cerebral perfusion.
The arch first technique does have some disadvantages. The relatively long lower body ischemic time may result in renal or hepatic dysfunction, poor recovery of gastrointestinal function or gastrointestinal bleeding. Recently, we have applied distal graft perfusion with a Folly catheter. This allows lower body perfusion even during distal anastomosis of the descending aorta or graft-to-graft anastomosis. The technique should reduce the duration of lower body ischemia and may improve the recovery of renal, hepatic or gastrointestinal function.
Hemostasis of the distal anastomosis site of the descending aorta is the most important point for total arch reconstruction, because it sometimes causes fetal bleeding that demands massive blood transfusion. We have applied a modified elephant trunk technique with a replicated graft. Four pieces of 2-0 polyvinylene retracting sutures were applied so as to make the distal anastomosis site shallow, and a tight running suture was made to achieve perfect anastomosis. Graft perfusion with a Folly catheter has the further advantage of confirming complete hemastasis of the distal anastomosis. With this technique, the proportion of patients requiring autologous blood transfusion decreases.
Median sternotomy also has certain advantages over left thoracotomy. In our experience, patients show quicker recovery of respiratory function after median sternotomy, and better quality of life with less wound pain in the late phase, than patients who underwent left thoracotomy. Also, the arch first technique is performed through median sternotomy with a small skin incision, since the arch vessels do not require full exposure.
We have performed individual anastomosis of each arch vessel with a four branched graft rather than island reconstruction. Elderly Japanese patients generally suffer from severe atherosclerotic changes on the orifices of each arch vessel. This technique is suitable for atherosclerotic aortic arches, because the arch vessels have fewer atherosclerotic changes. It also provides a better operative field for the distal anastomosis site or easy hemostasis for each anastomosis site. In the first 19 cases, we applied a handmade neoarch graft to reconstruct the arch vessels and give better exposure to the distal anastomosis site, but we now use a commercially available four branched graft. The length of each branched graft (several cm) allows mobilization of the arch graft and gives a better operative field, even for distal anastomosis sites. A four branched graft avoids a long suture line and simplifies the arch reconstruction.
In conclusion, we have presented our early clinical results of a recently refined arch first technique under circulatory arrest with retrograde cerebral perfusion. This technique is still developing, but some refinements definitely contribute to better clinical outcomes. The arch first technique is clearly superior to the conventional distal first technique in its surgical mortality and morbidity involving neurological outcomes. It also provides clinical results comparable to selective cerebral perfusion, and has the advantage that thrombo-embolism is less likely. We believe that our improvement of the surgical technique involved may act as a useful reference and contribute to the improvement of aortic surgery.
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References |
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TopAbstract1. Introduction2. Materials and methods3. Results4. DiscussionReferences |
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This article has been cited by other articles:
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  M.-H. Song, Y. Tokuda, M. Hirai, and Y. Ueda Learning Curve of Arch-First Technique Analyzed by Cumulative Sum Asian Cardiovasc Thorac Ann, December 1, 2007; 15(6): 507 - 510. [Abstract] [Full Text] [PDF]
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