Concomitant aortic root and pectus deformity repair in Marfan syndrome patients.

The role of concomitant aortic and pectus repair in Marfan patients remains controversial. We present our surgical technique for concomitant aortic repair of aortic root pathology and pectus correction. The concomitant surgery can be safely achieved in Marfan patients, thus, avoiding the need for a risky second stage operation.

Replacement of the esophagus with fascial flap-wrapped allogenic aorta.

BACKGROUND: Segmental replacement of the esophagus (SRE) is challenging. Allogenic aorta (AA) has shown promising remodeling abilities when used as an esophageal substitute. The aim of this study was to evaluate the feasibility and results of esophageal replacement with fascial flap-wrapped AA segments in a novel rabbit model. MATERIALS AND METHODS: Seven Geant des Flandres rabbits and one New Zealand rabbit served as thoracic aorta donors, and 25 New Zealand rabbits were used as recipients. One to 3 wk before esophageal replacement either cryopreserved or fresh thoracic aortic segments were wrapped in thoracic wall fascia to generate revascularization. In an attempt to optimize the model, step-by-step modifications concerning perioperative and postoperative management of the recipients were made as results accumulated. Microscopic evaluation was focused on the viability of aortic segments and neoangiogenesis originating from the fascia. RESULTS: Survival after SRE was poor. Most recipients died within 1 wk, mainly from upper digestive tract hypomotility. Microscopically, AAs were severely necrosed. In one recipient sacrificed on day 16, the edges of the graft became evanescent. In these areas, esophageal reepithelialization directly covered the fascia, in which unexpected smooth muscle cells were found, suggestive of the first stages of esophageal remodeling of the graft. CONCLUSIONS: Results for SRE using fascial-wrapped AAs in rabbits were disappointing. The transposition of this approach to larger animals might result in longer survival, increasing the possibility for more complete graft remodeling.

Extended autologous tracheal replacement by a novel pedicled thoraco-chondro-costal flap: a cadaveric proof of concept.

OBJECTIVES: Our aim was to report an anatomic model of an autologous flap based on the internal thoracic blood supply: the pedicled thoraco-chondro-costal flap; and establish the feasibility of various types of extended tracheal replacement with this novel flap, according to a newly proposed topographic classification. METHODS: In a cadaveric model, a cervicotomy combined with median sternotomy was performed. The incision was extended laterally to expose the chest wall. The internal thoracic pedicle was freed from its origin down to the upper limit of the delineated flap to be elevated. The perichondria and adjacent periostea were incised longitudinally to remove cartilages and adjacent rib segments, preserving perichondria and periostea. A full-thickness quadrangular chest wall flap pedicled on internal thoracic vessels was then elevated and shaped into a neo conduit to replace the trachea with the pleura as an inner lining. RESULTS: Various types of extended non-circumferential and full-circumferential tracheal replacements were achieved with this composite flap. No anastomosis tension was noticed despite the absence of release manoeuvres. CONCLUSIONS: This model could represent a suitable autologous tracheal substitute, which is long, longitudinally flexible and eventually transversely rigid. No microsurgical vascular anastomoses are required. The technique is reproducible. The perichondria and periostea would regenerate vascularized neo-cartilaginous rings, potentially decreasing the need for long-term stenting. The inner pleural lining could potentially transform into ciliated epithelium as shown in previous preclinical studies.

Full circumferential human tracheal replacement: a systematic review.

Full Circumferential Tracheal Replacement (FCTR) is a surgical challenge, indicated in rare cases of extensive tracheal resection, with no consensus on surgical technique or materials. A systematic review according to PRISMA guidelines was carried out from 2000 to 2022 to identify cases of FCTR, to compare surgical indications, the nature of the tracheal substitutes and their immunological characteristics, surgical replacement techniques and vascularization. Thirty-seven patients, including five children, underwent FCTR surgery using 4 different techniques: thyrotracheal complex allograft (n = 2), aorta (n = 12), autologous surgical reconstruction (n = 19), tissue-engineered decellularized trachea (n = 4). The mean follow-up was 4 years. Of the 15 deceased patients, 10 died of the progression of the initial pathology. For the majority of the teams, particular care was given to the vascularization of the substitute, in order to guarantee long-term biointegration. This included either direct vascularization via vascular anastomosis, or an indirect technique involving envelopment of the avascular substitute in a richly vascularized tissue. Stent placement was standard, except for autologous surgical reconstructions where tracheal caliber was stable. Internal stents were frequently complicated by granulation and stenosis. Although epithelial coverage is essential to limit endoluminal proliferation and act as a barrier, fully functional ciliated airway epithelium did not seem to be necessary. In order to facilitate future comparisons, a standardized clinical trial, respecting regulatory constraints, including routine follow-up with tracheal biomechanics assessment and scheduled biopsies could be proposed. It would help collecting information such as dynamics and mechanisms of tracheal bio-integration and regeneration.

Anterior Mediastinal Tracheostomy: Past, Present, and Future.

Anterior mediastinal tracheostomy (AMT) is established after division of the retrosternal trachea following resection of extended upper airway malignancies, stomal recurrences, or cervicomediastinal exenteration. AMT is occasionally performed for nonmalignant diseases. Starting in the 1980s, the use of a pectoralis major myocutaneous island flap reduced the mortality attributable to innominate artery rupture previously reported in historical series. Recent advances in the vascular reconstruction of supra-aortic trunks could allow future development of AMT as salvage surgery. On the other hand, construction of the stoma using free flap procedures and advances in chemoradiotherapy could simultaneously reduce the indication for AMT.

Successful immunosuppressant-free heterotopic transplantation of tracheal allografts in the pig.

OBJECTIVES: It has been demonstrated that both heterotopic and orthotopic transplants of epithelium-denuded cryopreserved tracheal allografts are feasible in immunosuppressant-free rabbits. Validation of these results in large animals is required before considering clinical applications. We evaluated the viability, immune tolerance and strain properties of such tracheal allografts heterotopically transplanted in a pig model. METHODS: Ten tracheal segments, 5 short (5 rings) and 5 long (10 rings), were obtained from male Landrace pigs. The tracheal segments were surgically denuded of their epithelium, then cryopreserved and stored in a tissue bank for 33 to 232 days. After thawing, tracheal segments stented with a silicone tube were wrapped in the omentum in 2 groups of 5 female recipients. The animals did not receive any immunosuppressive drugs. The animals were euthanized from Day 6 to Day 90 in both groups. RESULTS: An effective revascularization of allografts regardless of length was observed. Lymphocyte infiltrate was shown in the early postoperative period and became non-significant after 30 days. Allografts displayed high levels of neoangiogenesis and viable cartilage rings with islets of calcification. Biomechanical measurements demonstrated strain properties similar to those of a fresh tracheal segment from Day 58. CONCLUSIONS: Our results demonstrate the acceptability and satisfactory stiffness of epithelium-denuded cryopreserved tracheal allografts implanted in the omentum, despite the absence of immunosuppressive drugs. Since the omentum has the capability to reach the tracheal region, this approach should be investigated in the setting of orthotopic transplants in a pig model before considering clinical applications.

Tracheal replacement by allogenic aorta in the pig.

BACKGROUND: To assess whether fresh aortic allografts (AAs) can be used for tracheal replacement. METHODS: Twenty-one male minipigs underwent tracheal replacement using AAs harvested from female pigs. The length of replaced segments exceeded 50% of the trachea. A stent was implanted into the lumen of the AA to prevent collapse. The animals were killed at 3-month intervals, and AAs were assessed for ingrowth of respiratory epithelium and cartilage formation and tested for type II collagen formation and the presence of the SRY gene. RESULTS: A high stent migration rate was observed. Only 10 pigs and 4 pigs made it to follow-up periods exceeding 3 months and 9 months, respectively. Neither rejection nor ischemia were observed. At 3 months, a metaplastic epithelium lined the graft. At 10 months, a posterior membrane could be seen with immature cartilage and disorganized elastic fibers. SRY gene assay showed that the cells engrafted in the AAs, particularly at the level of the newly formed cartilage, were of male origin and thus originated from the recipient. CONCLUSION: This study confirms that a fresh AA, replacing more than half of the trachea of the pig, transforms into a conduit containing the major tracheal components. These components are relatively immature and do not as of yet replicate the form and function of the native trachea. Questions remain concerning the exact mechanisms of this process. Further research on the role of tracheal replacement is recommended.

Management of postintubation tracheobronchial ruptures.

STUDY OBJECTIVES: To determine whether nonoperative management can be applied to iatrogenic postintubation tracheobronchial rupture (TBR). DESIGN: Prospective cohort study. PATIENTS AND INTERVENTIONS: Thirty consecutive patients with TBR complicating intubation between June 1993 and December 2005 entered the study. Patients not receiving mechanical ventilation at time of diagnosis were treated nonsurgically. Patients receiving mechanical ventilation who were judged operable underwent surgical repair, while nonoperable candidates had their TBR bridged by endotracheal tubes. RESULTS: Fifteen patients not requiring mechanical ventilation underwent simple conservative management. TBR length measured 3.85 +/- 1.46 cm (mean +/- SD). Eight TBRs showed full-thickness rupture with frank anterior intraluminal protrusion of the esophagus. In three patients, transient noninvasive positive pressure ventilatory support (NIV) was necessary. All lesions healed without sequelae. Two patients receiving mechanical ventilation underwent surgical repair and died. Thirteen patients receiving mechanical ventilation were considered at high surgical risk, and TBR bridging was attempted as salvage therapy. Complete bridging was achieved in five patients by simply advancing the endotracheal tube distal to the injury. Separate bilateral mainstem endobronchial intubation was necessary in six patients whose TBRs were too close to the carina. Nine of 13 patients (69%) treated with nonoperative therapy completely recovered. CONCLUSION: We conclude that conservative nonoperative therapy should be considered in patients with postintubation TBR who are breathing spontaneously, or when extubation is scheduled within 24 h from the time of diagnosis, or when continued ventilation is required to treat an underlying respiratory status. Surgical repair should be reserved for cases in which NIV or bridging the lesion is technically not feasible.

Successful orthotopic transplantation of short tracheal segments without immunosuppressive therapy.

OBJECTIVES: Results of tracheal transplantation have been disappointing due to of ischaemia and rejection. It has been experimentally demonstrated that results of tracheal autograft/allograft transplantation were correlated with both graft length and revascularization method. Recently, we demonstrated that heterotopic epithelium-denuded-cryopreserved tracheal allograft (TA) displayed satisfactory immune tolerance. We aimed at evaluating the results of such allografts in orthotopic transplantation according to graft length and prior heterotopic or single-stage orthotopic revascularization in a rabbit model. METHODS: Twenty New Zealand rabbits were used. Six females served as donors. Tracheal mucosa was mechanically peeled off and then the TAs were cryopreserved. Male recipients were divided into three groups receiving: (i) long TA segment with prior heterotopic revascularization (10-12 tracheal rings, n = 3); (ii) average TA segment with single-stage orthotopic revascularization (6-8 tracheal rings, n = 4); (iii) short TA segment with single-stage orthotopic revascularization (4-5 tracheal rings, n = 7). No immunosuppressive therapy was administered. Grafts were assessed bronchoscopically and upon death or sacrifice by macroscopic evaluation, histology and immunohistochemical staining for apoptosis. RESULTS: Four animals were sacrificed from Day 33 to Day 220. The survival time of other recipients was 0-47 days (mean 19.6 ± 16.7 days). Aside from three animals that died from complications, all TA segments had satisfactory stiffness, were well vascularized, showed varying levels of neoangiogenesis and inflammatory infiltration devoid of lymphocytes, and showed evidence of only low levels of apoptosis. Varying degrees of fibroblastic proliferation originating from the lamina propria were observed in the lumen of all TAs and evolved over time into collagenized fibrosis in animals surviving over 45 days. Likewise, cartilage tracheal rings exhibited central calcification deposits, which started on Day 16 and increased over time. Epithelial regeneration was constantly observed. Intense fibroblastic proliferation led to stenosis in all animals from Groups (i) and (ii) but only one of seven animals from Group (iii). CONCLUSIONS: Our results suggest that short segments of epithelium-denuded-cryopreserved TA may be reliable for tracheal transplantation in the rabbit model without problems related to graft stiffness or immune rejection. Before considering clinical applications, investigations should be conducted in larger mammals.

Cardiac surgery and repair of pectus deformities: When and how?

OBJECTIVES: There is currently a lack of recommendations about patients with pectus deformities requiring cardiac surgery. This study reports the results of our surgical strategy on this issue. METHODS: Eleven patients, from three centers treated over a 9-year period were included in this study. Pectus deformities were operated with a modified Ravitch procedure. In the case of pectus excavatum repair and concomitant cardiac surgery, subperichondrial resection of abnormal rib cartilages was always performed before the sternotomy and an easily removable retrosternal metallic strut was inserted at the end of the procedure ensuring anterior chest wall stability. During follow-up patients had to estimate their current appearance with a numeric scale ranging from 0 to 100. RESULTS: Mean age was 27 ± 9.4 years. Pectus excavatum was present in 8 patients and pectus arcuatum in 3. There were 6 Marfan syndrome patients. Nine patients had concomitant surgery and, 2 underwent pectus repair after a history of cardiac surgery. There was no operative mortality. In the case of concomitant surgery, heart exposure through median sternotomy was facilitated by abnormal rib cartilage resection. Median follow-up was 54 months (range 16.7-119.7). Mean cosmetic result evaluated by the patients was 97.3 (±2.5). CONCLUSIONS: In adults, concomitant scheduled surgery is reliable and offers excellent long-term cosmetic results. Moreover, it allows a better thoracic exposition with no added perioperative risk. The modified Ravitch technique seems more adequate in these patients as it can be used in all types of pectus deformities.

Outcome at 2 years of infants with congenital diaphragmatic hernia: a population-based study.

BACKGROUND: Management of neonates with congenital diaphragmatic hernia (CDH) has undergone many changes associated with increased survival of high-risk CDH. However, little is known about the long-term outcome of CDH infants. METHODS: Follow-up was performed in 85 newborn infants with CDH admitted in our neonatal intensive care unit between January 1991 and December 1998. Early (< 2 months) and late mortality (> or = 2 months), and respiratory, nutritional, musculoskeletal, and neurosensory outcome at 2 years were recorded. RESULTS: Surgical repair was performed in 59 infants (69%) at a median postnatal age of 124 (range, 38 to 246) hours. Extracorporeal membrane oxygenation was used in 26 (30%) newborn infants. Survival at 2 years was 51 of 85 (60%) (early death, 28/85 [33%]; late death, 6/85 [7%]). Late deaths occurred because of persistent pulmonary hypertension or iatrogenic complications. Twelve of 51 (24%) newborn infants were oxygen dependant at the postnatal age of 28 days, and 1 of 51 (1.9%) was still oxygen dependant at 2 years. Growth failure was noted in 9 of 51 (18%), mainly related to severe gastroesophageal reflux and oral aversion. Scoliosis was diagnosed in 2 infants. Neurologic examination at 2 years was normal in 45 of 51 (88%). Cerebral palsy and developmental delay were observed in 2 and 4 infants, respectively. Four infants (8%) experienced associated problems. Respiratory, nutritional, and musculoskeletal morbidity was higher in infants treated by extracorporeal membrane oxygenation (p < 0.05). CONCLUSIONS: CDH infants are at risk for adverse nutritional and respiratory outcome. Despite severe respiratory failure at birth, prolonged oxygen therapy above 2 years of age is uncommon. Conversely, failure to thrive related at least in part to gastroesophageal reflux and oral dysfunction remains the major problem at 2 years of age. However, both nutritional and respiratory problems tend to improve with age.

Management of superior sulcus tumors: experience with 139 cases treated by surgical resection.

BACKGROUND: The management of non-small cell carcinomas of the lung involving the superior sulcus remains controversial. The goal of this retrospective study was to evaluate the role of surgery, radiotherapy, and chemotherapy for the treatment of superior sulcus tumors, to define the best surgical approach for radical resection, and to identify factors influencing long-term survival. METHODS: Between 1983 and 1999, 139 patients underwent surgical resection of superior sulcus tumors in seven thoracic surgery centers. According to the classification of the American Joint Committee, 51.1% of cancers were stage IIB, 13.7% stage IIIA, 32.4% stage IIIB, and 2.9% stage IV. RESULTS: The resections were performed with 74.1% using the posterior approach and 25.9% using an anterior approach. A lobectomy was accomplished in 69.8% of the cases and a wedge resection in 22.3%. Resection of a segment of vertebrae or subclavian artery was performed, respectively, in 19.4% and 18% of the cases. Resection was complete in 81.3% of cancers. The overall 5-year survival rate was 35%. Preoperative radiotherapy improved 5-year survival for stages IIB-IIIA. Surgical approach, postoperative radiotherapy, or chemotherapy did not change survival. CONCLUSIONS: The optimal treatment for superior sulcus tumors is complete surgical resection. The surgical approach (anterior/posterior) did not influence the 5-year survival rate. Preoperative radiotherapy should be recommended to improve outcome of patients with a superior sulcus tumor.

Acquired pulmonary vein stenosis as a cause of life-threatening pulmonary hypertension.

We report the case of an infant born prematurely at 27 weeks gestational age with life-threatening pulmonary hypertension crisis as a result of left upper pulmonary vein stenosis. Surgical treatment consisted of a lobectomy, which is a safe and effective procedure. Evidence strongly suggests that the venous stenosis may have resulted from hypertonic drugs infused through an umbilical catheter facing the upper left venous-atrial junction.

Immune tolerance of epithelium-denuded-cryopreserved tracheal allograft.

OBJECTIVES: Animal and clinical studies have demonstrated the feasibility of tracheal allograft transplantation after a revascularization period in heterotopy, thus requiring immunosuppressive therapy. Given the key role of the respiratory epithelium in the immune rejection, we investigated the consequence of both epithelium denudation and cryopreservation in immune tolerance of tracheal allograft in a novel rabbit model. METHODS: Five adult female New Zealand rabbits served as donors of tracheas that were denuded of their epithelium and then cryopreserved, and 13 males were used as recipients. Following graft wrap using a lateral thoracic fascial flap, allograft segments 20 mm in length with (n = 9) or without (n = 4) insertion of an endoluminal tube were implanted under the skin of the chest wall. The animals did not receive any immunosuppressive drugs. Sacrifices were scheduled up to 91 days. Macroscopic and microscopic examinations and detection of apoptotic cells by immunohistochemical staining (Apostain) were used to study the morphology, stiffness, viability and immune rejection of allografts. RESULTS: There were no postoperative complications. Grafted composite allografts displayed satisfactory tubular morphology provided that an endoluminal tube was inserted. All rabbits were found to have an effective revascularization of their allograft and a mild non-specific inflammatory infiltrate with no significant lymphocyte infiltration. Cartilage rings showed early central calcification deposit, which increased over time, ensuring graft stiffness. Apoptosis events observed into the allograft cells were suggestive of minimal chronic rejection. CONCLUSIONS: Our results demonstrated that the epithelium-denuded-cryopreserved tracheal allograft implanted in heterotopy displayed satisfactory morphology, stiffness and immune tolerance despite the absence of immunosuppressive drugs. This allograft with a fascial flap transferable to the neck should be investigated in the setting of tracheal replacement in rabbits. Similar studies need to be conducted in bigger mammals before considering clinical applications.