Agathe Seguin

Long-term evaluation of the replacement of the trachea with an autologous aortic graft

BACKGROUNDnTracheal reconstruction after extensive resection remains a challenge in thoracic surgery. The goal of this experimental study was to analyze the long-term evolution of tracheal replacement using an autologous aortic graft.nnnMETHODSnIn 21 sheep, a 5-cm segment of the cervical trachea was replaced by a segment of the descending thoracic aorta that was reconstructed to a prosthetic graft. Because of the airway collapse reported in a previous series, a permanent (n = 13) or temporary (n = 8) stent was systematically placed in the lumen of the graft. Clinical, bronchoscopic, and histologic examinations were performed up to 3 years after implantation.nnnRESULTSnAll animals survived the operation with no paraplegia. In the group with a permanent stent, three complications occurred: one stent displacement, one laryngeal edema, and one infection. Stent removal was tolerated after 6 months in the group with a temporary stent. Histologic examination showed a progressive transformation of the arterial segment into first extensive inflammatory tissue with a squamous epithelium, and after 6 to 36 months well-differentiated tracheal tissue including a continuous mucociliary epithelium and regular rings of newly formed cartilage.nnnCONCLUSIONSnAn autologous aortic graft used as a substitute for extensive tracheal replacement in sheep remained functional for periods up to 3 years. The progressive transformation of the graft into a structure resembling tracheal tissue seems to be a key factor in long-term patency. The mechanism of this regenerative process and the possibility of using arterial homografts, which would make clinical application easier, remain to be evaluated.

Tracheal Replacement With Cryopreserved, Decellularized, or Glutaraldehyde-Treated Aortic Allografts

BACKGROUNDnSeven years of experimental research provided a valuable tracheal substitute, the aortic allograft, which can promote the regeneration of epithelium and cartilage. In human application, both fresh and preserved aortic allografts could be used. The optimal method of aortic allograft preservation remains to be evaluated. This study assessed the use of cryopreserved, decellularized, or glutaraldehyde-treated aortic allografts as tracheal substitutes.nnnMETHODSnTwenty-two sheep underwent tracheal replacement using cryopreserved (n = 10), decellularized (n = 7) or glutaraldehyde-treated (n = 5) allografts, supported by a temporary stent to prevent airway collapse. Aortic segments were retrieved at regular intervals up to 12 months after implantation to analyze the regenerative process.nnnRESULTSnAll animals survived the operation. Major complications such as infection, stent migration, or obstruction were predominantly encountered in the decellularized group. The lack of major inflammatory response within the aortic graft observed in the glutaraldehyde group was associated with the absence of tracheal regeneration. Histologic examinations showed a progressive transformation of the aorta into a tracheal tissue comprising respiratory epithelium and cartilage only in the cryopreserved group.nnnCONCLUSIONSnThis study demonstrated that regeneration of a functional tissue could be obtained after tracheal replacement with a cryopreserved aortic allograft. The regenerative process followed the same pattern as previously described for fresh allografts. Cryopreserved aortic allografts present major advantages: availability in tissue banks, permanent storage, and no need for immunosuppression. This offers a new field of perspectives for clinical application in patients with extensive tracheal cancer.

Human Transplantation of a Biologic Airway Substitute in Conservative Lung Cancer Surgery

BACKGROUNDnPneumonectomies for lung cancer are associated with a high postoperative mortality, especially when right-sided, after neoadjuvant radiochemotherapy, and in patients over 70 years of age. Preliminary studies in our laboratory have shown that aortic grafts could be valuable airway substitutes. We report the first human bronchial transplantation of a cryopreserved aortic allograft used as a biologic airway substitute to prevent a pneumonectomy for lung cancer.nnnMETHODSnThe procedure was performed in a high-risk 78-year old patient with an extensive right bronchopulmonary malignant tumor pretreated with chemotherapy. After a complete resection of the lung cancer using an upper bilobectomy with lymph node removal, mobilization procedures did not allow for a primary end-to-end bronchial anastomosis. A stent-supported cryopreserved aortic allograft from a certified tissue bank was interposed to restore the bronchial continuity with sparing of the lower lobe.nnnRESULTSnThe postoperative course was eventful for a supraventricular arrhythmia leading to mild pulmonary edema that resolved using standard medical therapy, and a right lower lobe atelectasis with bacterial colonization that required fiberoptic bronchoscopies in addition to antibiotic treatment. A 1-year postoperative evaluation found a well-functioning reimplanted lower lobe with no complications related to the cryopreserved aortic allograft or the stent. The patient recovered to his baseline activity with a satisfying health-related quality of life.nnnCONCLUSIONSnWe demonstrate the feasibility of this surgical innovation to prevent the high-risk procedure of pneumonectomy in a single case. If confirmed in larger series of selected patients, it could bring new perspectives in conservative lung cancer surgery.

Bronchial Replacement With Arterial Allografts

BACKGROUNDnPneumonectomy is well known for a high risk of postoperative death. The alternative, sleeve lobectomy, is sometimes technically inaccessible, and is associated with locoregional recurrence. In certain situations, the use of a bronchial substitute would allow longer bronchial resections with better security margins. Previous experiments demonstrated that aortic grafts are valuable tracheal and carinal substitutes. The present study evaluated bronchial replacement with arterial allografts.nnnMETHODSnFifteen female sheep underwent a left bilobectomy with replacement of the bronchus intermedius with arterial allografts: 5 received a fresh graft (group 1) and 10 received cryopreserved (group 2). A bronchial silicone stent was used to confer rigidity. Evaluation was conducted on clinical and histologic criteria at regular intervals up to 18 months.nnnRESULTSnThere were no perioperative deaths. Atelectasis, the only early postoperative complication (n = 2), was successfully treated by fiberscopic aspiration. The late postoperative period was uneventful in 12 sheep. Complications included 1 bronchopneumonia, 1 pulmonary abscess, and 1 distortion of the bronchial stent. Fiberscopic examination revealed 3 sheep with granuloma formation. The bronchial stent was removed in 3 sheep, 1 at 9 months and 2 at 12 months, without clinical complications or stenosis of the graft. Histologic analysis showed regeneration of new bronchial tissue, comprising epithelium and cartilage.nnnCONCLUSIONSnThis study confirmed that an arterial allograft could be a valuable bronchial substitute. The use of a bronchial substitute offers new perspectives in surgical resection of lung cancer because it would avoid pneumonectomy in some patients.

Intracardiac renal cell carcinoma metastasis.

Cardiac involvement by intravascular protruding renal cell carcinoma is a well-recognised phenomenon. It most commonly occurs through inferior vena cava extension. Here, we report a case of a lower lobar lung metastasis from renal cell carcinoma involving the left atrium via the inferior pulmonary vein in a patient presenting with von Hippel-Lindau disease. Complete surgical resection was achieved under cardiopulmonary bypass.

Biopsie pulmonaire chirurgicale : indications et incidences thérapeutiques

Surgical biopsy of lung parenchyma can be used to establish a diagnosis in interstitial lung disease both of acute and chronic presentation. The present article summarizes the current indications, the therapeutic implications, the different surgical techniques and postoperative complications of the procedure. Common controversies and problems related to surgical lung biopsy are also presented.

Mise au pointBiopsie pulmonaire chirurgicale : indications et incidences thérapeutiquesSurgical lung biopsy: Indications and therapeutic implications

Surgical biopsy of lung parenchyma can be used to establish a diagnosis in interstitial lung disease both of acute and chronic presentation. The present article summarizes the current indications, the therapeutic implications, the different surgical techniques and postoperative complications of the procedure. Common controversies and problems related to surgical lung biopsy are also presented.

Tumeurs malignes de la trachée

Les tumeurs malignes de la trachee sont rares. Les lesions primitives sont principalement le carcinome epidermoide et le carcinome adenoide kystique. Le diagnostic est habituellement retarde du fait de la latence clinique. La bronchoscopie est un examen fondamental dans le bilan preoperatoire. Le traitement assurant la meilleure survie a long terme est la chirurgie (resection-anastomose tracheale). Au-dela de lesions etendues a plus de la moitie de la trachee (5–6 cm), un substitut tracheal doit etre utilise pour la reconstruction. La recherche d’un greffon tracheal ideal fait l’objet de nombreux travaux actuellement. Le traitement par bronchoscopie interventionnelle (electrocoagulation, mise en place d’endoprothese) peut etre utilise en cas d’obstruction tumorale aigue ou chronique, mais doit etre considere comme palliatif. La radiotherapie et/ou la chimiotherapie sont d’efficacite inconstante.

Chirurgia della trachea e dei bronchi: ruolo della broncoscopia interventistica per le lesioni non chirurgiche

Esiste, oggi, un numero importante di tecniche endoscopiche che permettono la disostruzione e/o la calibratura, che si tratti dell’utilizzo del broncoscopio stesso, dell’elettrocoagulazione, della plasmacoagulazione all’argon o, ancora, della crioterapia. La scelta dell’una o dell’altra di queste tecniche, cosi come i rispettivi vantaggi e svantaggi, sono descritti rapidamente. Inoltre, dall’utilizzo e dallo sviluppo delle endoprotesi tracheobronchiali, le indicazioni della chirurgia della trachea e dei bronchi sono notevolmente diminuite. Esistono schematicamente due tipi di protesi: le protesi metalliche e le protesi in silicone. Benche nessuna rappresenti la protesi ideale per le vie aeree, esse permettono di ripristinare il calibro delle vie aeree cosi come di migliorare i sintomi e la funzionalita respiratori. La scelta delle protesi e guidata dalla lesione da trattare, dalla perennita da ipotizzare o, ancora, dal posizionamento temporaneo del dispositivo. E anche influenzata ampiamente dall’esperienza degli operatori. Noi ne offriamo, dunque, un approccio terapeutico, senza voler essere dogmatici in questo settore.