Successful bronchial revascularization in experimental single lung transplantation

It is the purpose of this paper to report our experience with bronchial artery revascularization in an experimental model of single lung transplantation in swine. Thirty-three large white pigs weighing 20-40 kg underwent left lung allotransplantation. In 24 animals, bronchial artery revascularization was attempted by anastomizing the aortic patch containing the bronchial artery orifice with the recipient descending aorta. Eight survivors were put to death on postoperative days 11-15; five animals were put to death or died on postoperative days 2-9; the other animals died intra-operatively or within a few hours. Preservation of left bronchial vascularization was achieved in all cases attempted, as documented by post-mortem injection of dye (methylene blue) or contrast medium. Five of the 8 animals surviving for 11-15 days showed diffuse graft hepatization, associated with diffuse vascular thrombosis. Whether this was caused by damage to the endothelium due to poor graft preservation or by rejection was unclear. In animals surviving for 11-15 days without gross lung pathology, the anastomosis and bronchial mucosa were completely normal; in contrast, bronchial ischaemic changes were found in nonrevascularized animals and in survivors with graft hepatization. Our experience confirms that re-anastomosis of the bronchial arteries can prevent bronchial healing problems in single lung transplantation. The pig is an ideal model for these experiments since the bronchial arteries have a constant common aortic origin, allowing easy identification and preservation of left bronchial vascularization.     

Direct revascularization of bronchial arteries for lung transplantation: an anatomical study

Direct revascularization of the bronchial arteries for both single-lung and double-lung transplantation would improve airway healing and reduce airway complications after transplantation. We studied the anatomical pattern of bronchial arteries in 30 autopsy cases. In 28 of 30 cases (93.3%), at least one left bronchial artery arose directly from the anterior wall of the descending thoracic aorta. In 25 of the 30 cases (83.3%), at least one right bronchial artery was related to the first right intercostal artery. Injection studies showed that this right intercostobronchial artery supplies the proximal left main bronchus and carina as well as the right bronchus. We developed a technique for extracting the lungs along with the right intercostobronchial artery and a patch of aorta at its origin and applied it to 19 of the dissections. In 17 of the 19 cases studied (89.4%), the right intercostobronchial artery pedicle obtained had a length varying from 6.5 to 8.5 cm, sufficient for attachment of its origin to the ascending aorta of the recipient after double-lung transplantation. The right intercostobronchial artery pedicle provides the possibility for direct bronchial revascularization in right single-lung, double-lung, and lung-heart transplantation. A similar technique, utilizing the left bronchial artery, can be used to revascularize a left lung transplant.     

Cryopreserved iliac artery allograft for primary arterial revascularization in adult liver transplantation

Arterial allograft represents a material of choice for primary arterial revascularization in liver transplantation (LT) when interposition of a vascular conduit is required. In case of non-availability of such graft, the use of cryopreserved vessels should be an interesting option. Three patients were grafted using a cryopreserved iliac artery allograft (CIAA) previously harvested and stored at -140°C in a tissue bank. An auxiliary partial LT was performed in one patient for acute liver failure. During follow-up, an efficient regeneration of the native hemi-liver was observed while atrophy of the auxiliary graft occurred, leading to functional portal vein and hepatic artery thrombosis at six and nine months, respectively. Two other patients presented with celiac trunk compression because of arcuate ligament without available arterial allograft in the donor. Late arterial thrombosis occurred at six months in one patient without impairment of graft function. The last patient was alive and symptom free 29 months after LT with a patent cryopreserved arterial conduit. Our preliminary results suggest that CIAA might represent an efficient solution as vessel interposition for primary arterial hepatic revascularization in LT setting when no other suitable graft is available. However, long-term patency of CIAA remains questionable.     

A modified bronchial anastomosis technique for lung transplantation

BACKGROUND: Low rates of major complications have been reported for the intussuscepting bronchial anastomotic technique but stenosis, malacia, and granulation tissue at the anastomosis may cause clinically important morbidity. We hypothesized that a modification of the telescoping technique that improves bronchial wall apposition might be associated with improved bronchial healing and clinical outcomes. METHODS: The telescoping horizontal mattress "U-stitch" suture technique was modified to incorporate figure-of-eight sutures placed in the cartilaginous wall between each of three intussuscepting U stitches. Serial videotape records of 152 individual anastomoses (99 modified, 53 telescoped) in 118 consecutive operative survivors were retrospectively reviewed by examiners blinded with respect to technique used. Stenosis, airway instability, mucosa quality, and devascularized luminal tissue were graded at 4 to 14 days (initial), 4 to 12 weeks (early), and 6 to 12 months (late) after transplantation. RESULTS: The incidence of anastomotic stenosis was significantly lower using the modified technique at the initial (p = 0.025) and late (p = 0.015) observations. In the initial phase airway instability (p = 0.015) and devascularization grades (p = 0.001) were also significant lower in the modified group. There were no significant differences in mucosal condition between techniques. The modified telescoping technique was associated with significant survival advantage (mean 17.7%; p = 0.029) by multivariate analysis. The incidence of major airway complications (dehiscences and stenoses required stents) tended to be lower (3% versus 6%) in the modified group. CONCLUSIONS: The modified telescoping bronchial anastomosis technique is associated with improved early and late bronchial healing and higher 5-year survival without increased major airway complications.     

Coronary revascularization with arterial graft alone]

In the period from December 1989 until July 1991, coronary revascularization were performed on 56 patients using arterial grafts and no venous grafts. The ages of the patients ranged from 43 to 85 years (average; 66.8 years), and there were 33 males and 23 females. Twenty-four patients had angina pectoris, 23 had old myocardial infarction and 9 had acute infarction. There were 3 patients with single-vessel coronary disease, 19 with double-vessel, 31 with triple-vessel and 9 with left main coronary disease. The bypass grafts used were 58 left internal thoracic artery (LITA) grafts, 29 right internal thoracic artery (RITA) grafts, and 56 right gastroepiploic artery (RGEA) grafts. Thus, 143 grafts were used and an average of 2.6 bypasses were created per patient. There were two operative deaths. One of these patients had acute myocardial infarct. Investigation of postoperative graft patency was performed in the 122 grafts that could be examined angiographically after surgery. Only 7 were obstructed, yielding a patency rate of 94.3%. By using both the ITA and RGEA, in situ anastomoses with all the coronary arteries could be performed. Also in emergency surgery arterial grafting was possible. This operative form is considered to be a useful technique and may be expected to produce favorable long-term results.     

A new technique for double lung transplantation. "The bilateral single lung transplantation". Apropos of ten operations]

The technique of enbloc double lung transplantation described by the Toronto team, with cardiopulmonary bypass, cardioplegia, and tracheal suture is complicated by problems of tracheal anastomosis for its authors. Single lung transplantation has a more straight forward postoperative course and bronchial complications are moderate. We present a new technique of lung transplantation, the "bilateral single lung transplantation". It consists, via a single anterior horizontal incision, of successively performing two single lung transplantations without bypass. This operation has been performed ten times since November 1989. As expected, bronchial healing has been excellent.     

Isolated proximal revascularization for double aorto-iliac and femoral lesions]

From 1980 to 1990, 101 limbs were revascularized at the upper level only in 67 patients, while they presented with associated aortoiliac and femoral obstructive lesions. The symptoms disappeared after aortofemoral revascularization in 94% of the limbs operated on for claudication and 80% of those operated on for critic ischemia. Surgery of the deep femoral artery was associated in 51% of all cases. The average time lapse is 58 months. No complementary revascularization was needed in the cases of claudication. Out of the patients operated on for critic ischemia, upper revascularization was insufficient in 8 cases. Two of the operated patients were cured after secondary downstream revascularization (4%). Three operated patients still presented with intermittent claudication (6%), and 3 were amputed due to acute iliac obstruction seen at an advanced stage. As no reliable predictive test is available, we find it justified to carry out only upper revascularisation in most cases and to decide on the need for secondary downstream extension according to the clinical outcome. However, simultaneous revascularization at both levels is required in case of extensive involvement of the deep femoral artery, such as observed in only 5 of the patients operated during the same period.     

Bronchial circulation after experimental lung transplantation: the effect of direct revascularization of a bronchial artery.

Direct revascularization of a bronchial artery has been proposed as a measure to alleviate the problem of bronchial ischemia after lung transplantation. To assess the effect of restoration of arterial blood flow to the transplanted bronchus, bronchial mucosal blood flow was measured in a model of modified unilateral lung transplantation in pigs. Laser Doppler velocimetry (LDV) and radioisotope studies using radio-labeled erythrocytes (RI) were used to measure blood flow at the donor main carina (DC) and upper lobe carina (DUC) after 3 h of reperfusion. The recipient carina was used as a reference point; values obtained by LDV and RI were expressed as percentage of blood flow at the recipient carina. Two groups of animals were studied. In group 1 (n = 6) standard unilateral transplantation was performed; in group 2 (n = 6) a left bronchial artery was reimplanted into the descending thoracic aorta of the recipient. No differences were observed between the two groups with respect to preoperative or postoperative gas exchange or hemodynamics. In group 1, bronchial blood flow at the DC was 37.6 +/- 2.2% (LDV) and 44.1 +/- 14.8% (RI) of reference blood flow. At the DUC, blood flow was 54.9 +/- 7.7% (LDV) and 61.6 +/- 25.7% (RI) of normal flow. In group 2, blood flow was increased at the DC as measured by LDV (55.3 +/- 17.1%; p less than 0.05) and by RI (60.8 +/- 25.3%; p less than 0.2). A similar increase was found at the DUC (LDV: 81.8 +/- 19.3%; p less than 0.05; RI: 88.6 +/- 31.0%; p less than 0.2). It is concluded that there is a significant gradient of blood flow from intra- to extrapulmonary airways after lung transplantation. Reimplantation of a bronchial artery results in significant improvement of graft bronchial blood flow. Restoration of bronchial perfusion to normal levels, however, cannot be achieved, suggesting a possible defect in the microcirculation of the donor airways.     

Proliferating bronchial webs after lung transplantation

This case details the decline in lung function due to bronchial webs in a lung transplant recipient. The decline occurred 2 years after transplantation and, despite therapy, the webs, which had an inflammatory component, became treatment resistant. We outline the pathological findings and management strategies used, discuss the evidence in the literature, and offer possible causes for these unusual clinical findings.     

Normal bronchial healing without bronchial wrapping in canine lung transplantation.

The deleterious effect of steroids on bronchial healing in lung transplantation has led to the development of techniques to protect the anastomosis and to the exclusion of steroid-dependent patients from transplantation. The effect of steroids on bronchial healing was tested in a canine single-lung allotransplantation model. Twenty size-matched mongrel dogs (20 to 30 kg) underwent left lung transplantation without anastomotic wrap or direct revascularization. Postoperatively, all received daily doses of cyclosporine (15 mg/kg) and azathioprine (1 mg/kg) and were subdivided into three steroid dosage groups. Group A (n = 10) animals received 1.5 mg/kg of prednisone per day whereas groups B (n = 5) and C (n = 5) received 5.0 mg/kg of prednisone per day for 28 postoperative days. In addition, group C received prednisone (5.0 mg.kg-1.day-1) for 1 month preoperatively. In group A, 8 of 10 dogs survived 28 days without evidence of respiratory compromise, with anastomotic bursting pressure greater than 510 mm Hg. In group B, all 5 dogs survived to 28 days without evidence of respiratory compromise and with intact bronchial anastomoses (bursting pressures greater than 510 mm Hg). In group C, 3 of 5 animals survived to 28 days with intact anastomoses. Histological examination demonstrated normal bronchial healing in all anastomoses. These data suggest that preoperative steroid dependence should not be a contraindication to lung transplantation and that bronchial anastomotic wrapping with vascular tissue may not be essential.     

Reappraisal of bronchial arterial infusion therapy for advanced lung cancer

As preoperative adjuvant therapy for advanced lung cancer, bronchial arterial infusion (BAI) of a chemotherapeutic agent was administered to patients with stage IIIa and IIIb hilar lung cancer. The infusion modality was changed for each term, from a single drug infusion, to a two drug infusion and then a three drug infusion, and the combination of infused drugs was selected in accordance with cell types. A significant radiographic shrinkage was observed after BAI therapy by the single, two and three drug infusions, being noted as 40.7 per cent, 61.8 per cent and 83.9 per cent, respectively. The effect on squamous cell carcinoma was more prominent than on other cell types. Upon microscopic examination of the resected specimens, significant histo-pathological effects were observed in 57.7 per cent of the patients who received single or two drug infusions, while the rate increased to as high as 92.2 per cent in the patients who received the three drug infusion. The histological effects of BAI therapy were also most marked in squamous cell carcinoma. It is of special interest that 5 of the 10 patients who received the three drug infusion of Carboquone (CQ)+ Mitomycin C (MMC)+Nimustine-HCL (ACNU) for squamous cell carcinoma, showed complete disappearance of viable cancer cells at the tumor site; something which was never observed after the single and two drug infusions. It was therefore concluded that BAI therapy for advanced lung cancer should be reappraised through the modification of infusion methods.     

Reappraisal of bronchial arterial infusion therapy for advanced lung cancer

As preoperative adjuvant therapy for advanced lung cancer, bronchial arterial infusion (BAI) of a chemotherapeutic agent was administered to patients with stage IIIa and IIIb hilar lung cancer. The infusion modality was changed for each term, from a single drug infusion, to a two drug infusion and then a three drug infusion, and the combination of infused drugs was selected in accordance with cell types. A significant radiographic shrinkage was observed after BAI therapy by the single, two and three drug infusions, being noted as 40.7 per cent, 61.8 per cent and 83.9 per cent, respectively. The effect on squamous cell carcinoma was more prominent than on other cell types. Upon microscopic examination of the resected specimens, significant histo-pathological effects were observed in 57.7 per cent of the patients who received single or two drug infusions, while the rate increased to as high as 92.2 per cent in the patients who received the three drug infusion. The histological effects of BAI therapy were also most marked in squamous cell carcinoma. It is of special interest that 5 of the 10 patients who received the three drug infusion of Carboquone (CQ) + Mitomycin C (MMC) + Nimustine-HCL (ACNU) for squamous cell carcinoma, showed complete disappearance of viable cancer cells at the tumor site; something which was never observed after the single and two drug infusions. It was therefore concluded that BAI therapy for advanced lung cancer should be reappraised through the modification of infusion methods.     

Donor-recipient lung volume matching in double lung transplantation. Value of left lower lobe graft]

For double lung transplantation, lung volume matching is easier comparing the predicted total lung capacities of the donor and recipient and the recipient's true TLC. The major concern in the inability to close the chest when the donor lungs are too large. The technique reported of left lower lobe implantation during bilateral single lung transplantation might be of great value in patients with small lung volume.     

Cyclosporin and bronchial healing in canine lung transplantation

Long-term bronchial anastomotic healing has been assessed in the canine lung transplant model with cyclosporin as the primary immunosuppressant. Early bronchial revascularization was achieved by wrapping an omental pedicle around the bronchial anastomosis. Ten dogs underwent left lung transplantation and six survived 100 days or more before being put to death. No significant bronchial complications occurred. Late bronchostenosis was not seen, despite four biopsy-proved rejection episodes in three of the dogs surviving past 100 days. Histologically, all anastomoses were well healed at autopsy. Cyclosporin was shown to be an effective immunosuppressant in this model and was associated with prolonged survival and low morbidity. Transplant lung function was assessed at 100 days by contralateral pulmonary artery ligation in five dogs and was satisfactory in the three animals that had not had rejection episodes. The findings support our belief that bronchial anastomotic complications after human lung transplantation are mainly related to the effects of immunosuppression with steroids and to the ischemia resulting from division of the bronchial circulation at the time of transplantation.     

Bilateral bronchial anastomosis in double lung and heart-lung transplantations

During heart-lung or double lung transplantation, the airway anastomosis is usually made at the tracheal level. Healing of this anastomosis is one source of postoperative complications especially after double lung transplantation (DLT). In this series of 10 patients with cystic fibrosis undergoing DLT, the tracheas of donor and recipient were anastomosed with omental wrapping in 2 cases while the two main stem bronchi were joined without omental wrapping in 8. Endoscopy disclosed no sign of ischaemia in the patients with bilateral bronchial anastomoses. Three patients died on day 20, 21 and 35, respectively, after DLT. Two of these patients (one with a tracheal and the other with bronchial anastomoses) showed no complication at the level of the suture line. The third patient (with bronchial suture) suffered dehiscence of both anastomoses which was attributed to a misdosage of corticosteroids. Of the 6 patients alive after bronchial anastomosis, 3 recovered uneventfully and 3 who had required prolonged postoperative mechanical ventilation developed bronchomalacia. Bronchomalacia was treated by laser resection and stenting. Dehiscence did not occur in any of these six cases. This technique was based on the findings of 12 fresh cadaver dissections showing that collaterals between the bronchial arteries and the pulmonary arteries and veins extend up to the origin of the main stem bronchus. Bronchial suture without omental wrap may be used for double lung and heart-lung transplantation instead of tracheal suture.