This study spanned nine year’s experiences in surgical management of CTS. The outcomes of the study have clarified that slide tracheoplasty is a safe, effective and versatile technique which could be applicable for all types of CTS, even when bronchial stenosis exists. Moreover, the coexisting LPA sling could be managed by ante-tracheal translocation in almost all cases. The technique of reimplantation was retained for some cases as needed. Mortality was associated with long stenosis, accompanying cardiac anomalies and severe preoperative severe clinical status such as severe infection, cardiac arrests, hypoxia and severe respiratory distress necessitating aggressive ventilator support.
In our study, we found that tracheobronchial morphology could be classified in a simpler and more effective way with three surgical types which highly affected the sliding techniques: (1) entire stenosis of the trachea; (2) stenosis in some parts of the trachea; and (3) stenosis due to double carina or bridging bronchus. In each of these three types, unilateral or bilateral bronchial stenosis may have accompanied tracheal stenosis (Fig. 1). Several classifications of CTS had been proposed. Conventionally and commonly four types of Grillo (2004) [2] are used. More recently, Speggiorin (2012) [5] proposed four new types of congenital tracheobronchial stenosis. In our opinions, those classifications were more morphologically and more difficult to remember or differentiate in clinical practice. In addition, they do not help surgeons much in deciding the type of sliding techniques to use when performing tracheal reconstruction surgery.
Tracheal reconstruction surgery has changed a great deal over time. For cases of long stenosis, Bryant et al. first described the technique using a pericardial graft [6]. The advantages of pericardial grafts are that they are always available at the surgical site, are easy to harvest, have good air retention, are not subject to rejection, and the epithelium of the trachea can easily cover the graft [7]. However, pericardial graft is not a good choice for tracheal reconstruction because of its high rates of recurrent stenosis, prolonged hospitalization, and excessive granulation [8]. We do not use this technique for surgical reconstruction of the trachea. In 1989, Tsang first introduced the slide tracheoplasty technique [9], later edited by Grillo [10] and made many changes in surgery. The advantage of this method is that it uses the narrow trachea itself to reconstruct a new non-stenotic trachea (Fig. 1). Reports around the world show good results for this technique with overall mortality about 11% (Table 6). Furthermore, the data from the studies showed that the trachea was well developed after sliding [11].
Table 6
| Studies | Year | Number of patients | Mean age | Time of following up | Mortality rate | Airway reinterventions (*) |
| Tsang [9] | 1989 | 2 | 7 month | 12 months | 50% | Unclear |
| Grillo [10] | 1994 | 4 | 10.5 year | 17 months | 0% | Unclear |
| Manning [4] | 2011 | 80 | 8.7 month | Unclear | 5% | 42.5% |
| Butler [12] | 2015 | 101 | 5.8 month | 4.6 years | 11.9% | 49.5% |
| Wu(**) [13] | 2021 | 577 | Unclear | Unclear | 9.7% | 23% |
| Our study | 2022 | 67 | 7.6 month | 9 years | 13.4% | 8.9% |
(*) Airway reinterventions: minor reinterventions included granulation tissue removal or simple tracheal dilation; major reinterventions included tracheal stenting, revision open surgery, and tracheotomy. (**) A review of 25 studies.
We performed this technique in all patients with CTS in this study with good results. The mortality rate in this review was 13.4% and severe restenosis was 8.9%. Regarding the surgical technique, we used interrupted stitches with monofilament absorbable sutures. In the majority of other report, a continuous suture was used [4], [12]. In our opinion, interrupted stitches easily conformed to the shape of the newly created trachea and avoided folding at the suture line. CPB was always used for assisting the patient and for safety reasons. With CPB, the trachea can be easily dissected and a good tracheal reconstruction can be created without technical errors. For cases with bronchial stenosis, a modified sliding technique was proposed with reversed Y-shape reconstruction to widen the one or two bronchial openings showing stenosis (Fig. 1). This technique was first used in our study when performing a slide tracheoplasty in one neonate with CTS involving bilateral main bronchus. We found very few authors described the same technique with us for bronchial stenosis [14]. Concomitant bronchial stenosis may account for higher morbidity and mortality [12]. Fortunately, our results for these group were without complications. However, in our opinion, the severity of the accompanying bronchial stenosis could impose much more challenging in surgical techniques and outcomes. The more severe the bronchial stenosis is, the poorer prognosis will be! The age group in our study raged from 25 days to 8 years and the mortality rate of group below 6-month-old was very high (8.9%). In small-sized babies, the operation is much more difficult in surgical techniques and prognosis, therefore we have always been very stressful with those cases. However, the trachea is much more mobile and flexible in small babies so the entire tracheal stenosis could be managed easier. Bronchoscopy should be used routinely postoperatively. Our protocol for postoperative bronchoscopy were: (1) for cases with uneventful postoperative period, bronchoscopy was performed before extubation and discharge; (2) for cases with unfavorable postoperative outcomes such as unable to extubate, getting worse, bronchoscopy was performed as soon as possible to find out the reasons.
For the treatment of the left pulmonary artery sling, we translocated the LPA sling anteriorly to the trachea in 93.2% cases (corresponding to 41 cases of LPA sling), provided that we dissected free the two pulmonary arteries close to the hilum and dissected the pulmonary trunk away from the ascending aorta and the division of the ductus arteriosus. The advantage of this surgical approach was that we can significantly shorten the running time of the CPB because we do not have to spend time to reimplant the LPA and do not have to use anticoagulants after surgery. The approach also reduces the risk of thrombosis or stenosis at the insertion site (which maybe the cause of postoperative death). However, in some cases, the LPA sling was too kinked after ante-tracheal translocation, so we reimplanted it. We had three cases of LPA reimplantation but the outcomes were not good, all three of them died postoperatively. Van Son (1999) [15] advocated reimplanted of the LPA sling because it is more physiological and not compressed the anterior wall of the trachea, but Van Son’s data set is too small compared to ours. The possible explanation for our results may be that, because we operated on cases of LPA sling accompanied by severe CTS, a good tracheal reconstruction is more necessary than reimplantation or translocation of the LPA sling. Of forty cases of LPA sling antetracheal translocation, good postoperative results were found. We have not recorded any cases of LPA stenosis and recurrent stenosis due to the compression of the LPA sling on the anterior wall of the trachea.
In this study no ECMO was used, but emergency surgery was performed in 8 cases. The recurrent stenosis rate was 8.9% in which most were conservatively and successfully managed. In our opinion, the stenosis occurs when the everting suture techniques are not well effective enough, therefore inverting tracheal tissue at the suture line may induced granuloma formation which will result in recurrent stenosis. Reoperation was required in 2 cases of restenosis, accounting for 2.9%. One of these patients died after surgery. Both these patients were clinically in critical situations, with multiple cardiac arrests, lung infection occurring before surgery, and both requiring ventilator support. The mortality rate was 13.4%, corresponding to 9 patients, for which 4/9 cases (44.4%) were emergency surgery, 6/9 cases were in group of age below 6-month-old and 9/9 cases were in group of CPB time over 180 minutes. These outcomes may imply that age group, CPB time and critical clinical status such as cardiac arrests, severe lung infection, or acute respiratory distress requiring ventilator support could be a risk factor for poor prognosis. However, our data could not reveal the relationship with binary logistic regression analysis. Further investigation would be necessary to confirm this hypothesis.
The limitations of our study include the small sample size, some confounding factors due to individual experience of the surgeons, and modestly equipped medical facilities in our center. In contrast, this study presents one of the biggest data sets on surgical treatment of tracheal malformations in our country. The outcomes of this study with low mortality and morbidity would encourage surgical approaches for management of CTS. Moreover, our surgical approach of LPA sling antetracheal translocation maybe a good option, but continues to be a debatable approach and it remains hard to concluded the effectiveness of this technique. So far, very few studies have been available on the effectiveness of antetracheal translocation. In fact, future large-scale studies may be necessary to gain convincing information.