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Prosthetic reconstruction of the trachea
Prosthetic Reconstruction of the Trachea Ashok Shaha, MD, Therese DiMaio, MD, Samuel Money, MO, Yosef Krespi, MD, Bernard M. Jaffe, MD, Brooklyn,NewYork
Tracheal reconstruction has been a difficult and challenging problem over the years, mainly because of graft infection and extrusion. A small segment of the trachea can be resected and primary anastomosis can he performed easily with satisfactory results. The problem is always complex when a substantial portion of the trachea must be resected. A variety of prosthetic materials have been used, both in experimental animals and human subjects, with limited short-term success. This study describes an experiment using polytetrafluoroethylene (PTFE) grafts in dogs. PTFE patch and interposition grafts were used for tracheal reconstruction with very satisfactory results. Inflammatory reaction near the grafts and nonincorporation of long graft segments continue to be problems, but despite this, prosthetic reconstruction of the trachea using PTFE provided very satisfactory results in our experimental study.
tures, which causes fatal hemorrhage. Yet the grafts need to be rigid to prevent collapse [6,7]. The most important practical problem limiting the application of different prosthetic materials in human subjects is that when they fail, the outcome is generally fatal due to respiratory problems. Even though a variety of different prosthetic and autologous materials have been used for tracheal reconstruction, polytetrafluoroethylene (PTFE, Gore-Tex| has not been studied fully. Our experience with PTFE grafts, commonly used in vascular surgery and especially for creation of arteriovenous fistula, has demonstrated that this material resists infection much more effectively than do other materials, and the incidence of infection and extrusion is relatively low.
MATERIAL AND METHODS This experimental study was performed utilizing PTFE for tracheal reconstruction in dogs. Reconstruction was performed in two forms: a patch to cover tracheal windows and interposition ringed grafts for segmental tracheal resection. In part I of the experiment, healthy adult dogs weighing 15 to 18 kg were anesthetized with thiopental sodium (Pentothal| The dogs were intubated with a sterile endotracheal tube and placed on a ventilator. Anesthesia was continued with halothane. The neck of each animal was shaved and prepared with povidone-iodine solution. iseases requiring partial or segmental resection of the A vertical incision was made in the midline of the neck. trachea are fairly uncommon. However, these con- The trachea was exposed in the midline after separating ditions, including tumors and stenoses, pose a major sur- the strap muscles. The tracheal rings were exposed antegical challenge, since no effective method of long-seg- riorly and in lateral aspects after incising the pretracheal ment tracheal reconstruction is readily available [1]. fascia. An area of seven to eight rings was thus exposed. A Over the past half century, many investigators have tried rectangular window was made in the anterior wall of the a variety of different techniques for tracheal reconstruc- trachea involving five to six rings, and the anterior wall of tion, both in experimental animals and human subjects. the trachea was removed (Figure 1). This tracheal defect The success of these procedures has been limited. Al- was reconstructed with PTFE graft sutured in place using though the procedures seemed to be effective initially, the 3-0 prolene sutures. Patch tracheoplasty in this fashion long-term results were dismal. Even in experimental ani- was performed in 12 dogs. mals, a variety of prosthetic materials have been used but In part II of the experiment, using the same surgical all with a very limited degree of success [2-6]. The major approach, a tracheal segment consisting of approximately problem in tracheal reconstruction has been infection and seven to eight rings was resected. During the procedure, resultant extrusion of the graft. The main source of infec- after incising the trachea above and below, the endotration is contamination from the trachea either at the time cheal tube was withdrawn momentarily, the ringed PTFE of initial implantation or subsequent to it. Unfortunately, graft was placed in the defect, and the endotracheal tube this contamination cannot be avoided. was reinserted through the graft segment in the lower The main complication of the prosthetic materials has portion of the trachea. Anesthesia was continued until the been erosion into the surrounding vital vascular struc- anastomoses were completed. Ringed PTFE grafts 16 to 20 mm in diameter were used. The anastomoses were From the Departmentsof Surgeryand Pathology,State Universityof performed with 3-0 prolene sutures. The rings covering New YorkHealthScienceCenterat Brooklyn,Brooklyn,New York. the graft were made of fluorinated ethylene propylene. Requests for reprints shouldbe addressedto AshokShaha, MD, Fourteen dogs were included in this second portion of the Box40, Departmentof Surgery,State Universityof New YorkHealth experiment (Figures 2 and 3). ScienceCenter,450 ClarksonAvenue,Brooklyn,New York 11203. In both parts of the experiment, each dog was given Presentedat the 34th AnnualMeetingof the Societyof Head and Neck Surgeons,New Orleans,Louisiana,May 22-26, 1988. 1 g of cephalosporin preoperatively. All the dogs were
D
306
THE AMERICAN JOURNAL OFSURGERY VOLUME156 OCTOBER1988
9 .-."
~ 9
I +.
.':-
.
.
.
.
,.'
J
~j
Figure 1. The tracheal window Involving six to seven rings. Patch graft performed with polytetrafluoroethylene.
Figure 2. Segmental resection and reconstruction with ringed polytetrafiuoroethylene InterposlUon graft.
extubated at the conclusion of the experiment and none had tracheostomy. The animals were fed after 12 hours. The dogs were sacrificed 8 to 16 weeks after the procedure, and the tracheas with the grafts were removed and studied histopathologically.
chea was exposed, it was apparent that there was considerable fibrosis around the graft; however, the grafts were not incorporated in the trachea. The grafts appeared to be held in place by the prolene stitches. Histologic study revealed considerable mucosal relining by the epithelium from one cut edge of the trachea to the other. There was also evidence of attempted regrowth of the mucosa over the graft; however, the grafts were not ineorported in the trachea. Fourteen dogs had interposition with ringed PTFE grafts after excising a segment of trachea 7 to 8 rings in length. None of the dogs had air leak, subcutaneous emphysema, or erosion of the prosthesis into the surrounding structures during this part of the experiment. Only one dog died in this group (3 weeks after tracheal reconstruction), presumably due to granulation tissue and narrowing at the anastomotic site. The remaining 13 dogs were
RESULTS Twelve dogs had patch tracheoplasty with PTFE grafts. All did well in the immediate postoperative period. There were no air leaks or subcutaneous emphysema. One dog died suddenly 2 weeks after the operation. Autopsy revealed graft separation and tracheal obstruction due to the presence of graft material in the lumen. One other dog died 289 weeks postoperatively due to wound infection and graft separation. Thus, 10 dogs did well and portions of their tracheas were removed 8 to 16 weeks postoperatively to evaluate graft status. When the tra-
THE AMERICANJOURNALOF SURGERY VOLUME156 OCTOBER1988 307
SHAHA ET AL
Figure 4. AnastomoUc area between the polytetrafluoroethylene graft and trachea.
tion and had no airway problems, None of them required tracheostomy and none had difficulty in swallowing.
Figure 3. Ringed polytetrafluoroethylene graft In place after segmental resection of the trachea.
TABLE I
Ideal Prosthetic Material for Tracheal Reconstruction 1. 2. 3. 4. 5. 6. 7. 8.
Inert Growth of tissue into the graft Should not collapse Development of mucosal lining (?) Air tight Long-term success Not too rigid to erode into surrounding structures Resists infection and extrusion
sacrificed 10 to 16 weeks later and their graft-trachea anastomoses were studied histopathologically. As with the window group, the grafts were not incorporated in the trachea. Instead, they were held to the trachea only by the prolene stitches. There was evidence of attempted mucosal relining at the area of the graft-trachea anastomosis, however, this extended only over a very short area of graft. The remaining portion of the graft from one end to the other had no mucosal lining. Some granulation tissue at the anastomotic site was also seen, but the narrowing did not result in any airway problems (excluding the dog mentioned earlier) (Figure 4). It is important to note that all the dogs tolerated both procedures well and there were no early postoperative problems. The dogs were extubated soon after the opera308
THE AMERICAN JOURNAL OFSURGERY
COMMENTS If a small segment of the trachea is to be resected, reconstruction can be performed by primary anastomoses after mobilizing the trachea. Approximately five to six rings of the trachea can be removed and the cut ends reapproximated. The success rate of this technique is excellent. The technique was perfected by Grillo [8-10], who reported a large series of patients who underwent resection and primary anastomosis of the trachea. However, problems appear when a large segment of the trachea must be resected. Even though there are few indications for such an extensive tracheal resection, reconstruction under such circumstances is always difficult and frought with major complications. An ideal tracheal prosthesis should be inert and airtight (Table I). It should be rigid enough that it does not collapse and, at the same time, should not erode into the surrounding vital structures. It should be incorporated into the surrounding tissues and provide long-term success. Despite the fact that investigators have tried to find an ideal prosthesis for the past half century, no perfect prosthesis is currently available. Long-term problems remain. The silicone tracheal prosthesis described by Neville [6,7] has had limited success. The two major problems associated with prosthetic tracheal reconstruction are infection and extrusion of the graft. From a clinical standpoint, this complication is generally fatal. PTFE grafts have been used routinely for arteriovenous fistulas with excellent results. Although we have seen a number of infected grafts in intravenous drug abusers, these infections have not been major problems and extrusion of'the grafts, even in the presence of infection, has been rare. Using the same principle, we have used the PTFE graft for tracheal reconstruction in the form of a patch or a segment. The rings made of fluorinated ethylene propylene are noncollapsible. The early results of our study are quite promising. The dogs appeared to tolerate the procedure very well with few major postoperative problems over a follow-up period of 3 to 4 months. Whether this has any long-term implications is difficult to predict at this
VOLUME 156
OCTOBER 1988
PROSTHETIC RECONSTRUCTION OF THE TRACHEA
time; however, the fact that an extensive segment of trachea was removed and reconstructed is very exciting. Although PTFE grafts did not become incorporated in the tracheal wall, there was considerable fibrosis around the trachea. The question regarding a need for the development of a mucosal lining in the entire length of the tracheal prosthesis has not been clearly answered [5]. In dogs with patches, there was an attempt at reepithelialization from one cut edge of the trachea to the other. Although it was apparent that small defects were reepithelialized from surrounding mucosal growth, there was no mucosal lining on the interposition grafts, even though there was some attempt at epithelialization near the graft-trachea anastomosis. However, this lack of mucosal lining did not seem to cause any major functional problems, at least during the 3- to 4-month observation period. There was inflammatory reaction noted at the site of graft anastomosis with minimal granulation tissue; however, this did not create any practical problems. PTFE grafts appear to be very useful for tracheal reconstruction and quite promising when used in the forms of a patch and segment. Future research should be
directed to studying the long-term effects of tracheal reconstruction. REFERENCES 1. Maassen W, Greschuchna D, Vogt-Moykopf I, Toomes H, Lullig H. Tracheal resection: state of the art. Thorac Cardiovasc Surg 1985; 33: 2-7. 2. Habal D, Pizzoferrato A, Vespucci A. Prosthetic replacement of large defects of the cervical trachea in dogs. Biomaterials 1985; 6: 17. 3. Scherer MA, Ascheri R, GeissdSrfer K, et al. Experimental bioprosthetic reconstruction of the trachea. Arch Otorhinolaryngol 1986; 243: 215-23. 4. Toomes H, Mickisch G, Vogt-Moykopf I. Experiences with prosthetic reconstruction of the trachea and bifurcation. Thorax 1985; 40: 32-7. 5. Vos GA, Patka P, Klein C, Hoitsma H, Degroot K. Tracheal reconstruction with hydroxyapatite tracheal prosthesis. Life Support Syst 1986; 4: 283-7. 6. Neville WE, Bolanowski PJ. Tracheal reconstruction. Surg Annu 1979; 11: 225-47. 7. Neville WE. Prosthetic reconstruction of trachea. Laryngol Otol Rhinol 1982; 103: 153-4. 8. Grillo HC. Tracheal surgery. J Thorac Cardiovasc Surg 1983; 17: 67-77. 9. Grillo HC, Zannini P, Michelassi F. Complications of tracheal reconstruction. J Thorac Cardiovasc Surg 1986; 91: 322-8. 10. Grillo HC. Tracheal tumors: surgical management. Ann Thorac Surg 1978; 26:112-25.
EDITORIAL COMMENT Mukund S. Didolkar, MD, Baltimore,Maryland
The trachea imposes a formidable challenge when resected and anastomosed. Nearly half its length can be resected and anastomosed without using prosthetic material for most common indications such as tracheal stenosis after prolonged intubation or tracheostomy and resection of primary or metastatic tumors. On occasion, mobilization of tracheal segments is difficult, and rarely more than half the length of trachea needs to be resected. Such rare situations necessitate the use of tracheal prostheses. Since the beginning of this century, several metal and synthetic materials have been used in experimental and clinical situations. Bioprosthetie materials with allografts and xenografts have also been used recently. For successful tracheal prosthetic reconstruction, the material should From the Department of Surgeryl University of Maryland, Baltimore, Maryland.
have the following qualities: airproof seal; good tissue tolerance with minimal reaction; resistance to infection and incrustation; surface epithelialization; mechanical stability; no toxicity; biocompatibility, and nonimmunogenicity. The authors of the preceding study used polytetrafluoroethylene (PTFE) grafts, a widely used material in vascular surgery, for tracheal reconstruction in a canine model. Although tissue tolerance and air-proof quality were excellent in their experiment, surface epithelialization and incorporation into the tissue was not noted. In a vast vascular surgery experience, resistance to infection in an infected field has not been noted; therefore, if PTFE grafts are used in clinical situations for tracheal reconstruction, the bronchopulmonary bacterial flora would easily infect the graft. The sequellae of infection, ineluding bleeding, erosion of neck or thoracic vessels, graft extrusion, and
THE AMERICAN JOURNAL OF SURGERY
pulmonary infection, would readily follow. The authors have a follow-up of 3 to 4 months only, which is a rather short period of time to see such life-threatening complications. The most commonly used silicone prosthesis, which was described by William Neville [1,2] has not gained popularity because of long-term problems. The application of the bioprosthetic material described by Scherer et al [3] may need to be explored more than PTFE or other synthetic materials in the future. Osteomyocutaneous flaps could also be considered for tracheal reconstruction. 1. Neville WE, Bolanowski PJ. Tracheal reconstruction. Surg Annu 1979; 11: 225-47. 2. Neville WE. Prosthetic reconstruction of trachea. Laryngol Otol Rhinol 1982; 103: 153-4. 3. Scherer MA, Ascherl R, GeissdSrfer K, et al. Experimental bioprosthetie reconstruction of the trachea; Arch Otorhinolaryngol 1986; 243: 215-23.
VOLUME !56
OCTOBER 1988
309
Tracheal reconstruction has been a difficult and challenging problem over the years, mainly because of graft infection and extrusion. A small segment of the trachea can be resected and primary anastomosis can he performed easily with satisfactory results. The problem is always complex when a substantial portion of the trachea must be resected. A variety of prosthetic materials have been used, both in experimental animals and human subjects, with limited short-term success. This study describes an experiment using polytetrafluoroethylene (PTFE) grafts in dogs. PTFE patch and interposition grafts were used for tracheal reconstruction with very satisfactory results. Inflammatory reaction near the grafts and nonincorporation of long graft segments continue to be problems, but despite this, prosthetic reconstruction of the trachea using PTFE provided very satisfactory results in our experimental study.
tures, which causes fatal hemorrhage. Yet the grafts need to be rigid to prevent collapse [6,7]. The most important practical problem limiting the application of different prosthetic materials in human subjects is that when they fail, the outcome is generally fatal due to respiratory problems. Even though a variety of different prosthetic and autologous materials have been used for tracheal reconstruction, polytetrafluoroethylene (PTFE, Gore-Tex| has not been studied fully. Our experience with PTFE grafts, commonly used in vascular surgery and especially for creation of arteriovenous fistula, has demonstrated that this material resists infection much more effectively than do other materials, and the incidence of infection and extrusion is relatively low.
MATERIAL AND METHODS This experimental study was performed utilizing PTFE for tracheal reconstruction in dogs. Reconstruction was performed in two forms: a patch to cover tracheal windows and interposition ringed grafts for segmental tracheal resection. In part I of the experiment, healthy adult dogs weighing 15 to 18 kg were anesthetized with thiopental sodium (Pentothal| The dogs were intubated with a sterile endotracheal tube and placed on a ventilator. Anesthesia was continued with halothane. The neck of each animal was shaved and prepared with povidone-iodine solution. iseases requiring partial or segmental resection of the A vertical incision was made in the midline of the neck. trachea are fairly uncommon. However, these con- The trachea was exposed in the midline after separating ditions, including tumors and stenoses, pose a major sur- the strap muscles. The tracheal rings were exposed antegical challenge, since no effective method of long-seg- riorly and in lateral aspects after incising the pretracheal ment tracheal reconstruction is readily available [1]. fascia. An area of seven to eight rings was thus exposed. A Over the past half century, many investigators have tried rectangular window was made in the anterior wall of the a variety of different techniques for tracheal reconstruc- trachea involving five to six rings, and the anterior wall of tion, both in experimental animals and human subjects. the trachea was removed (Figure 1). This tracheal defect The success of these procedures has been limited. Al- was reconstructed with PTFE graft sutured in place using though the procedures seemed to be effective initially, the 3-0 prolene sutures. Patch tracheoplasty in this fashion long-term results were dismal. Even in experimental ani- was performed in 12 dogs. mals, a variety of prosthetic materials have been used but In part II of the experiment, using the same surgical all with a very limited degree of success [2-6]. The major approach, a tracheal segment consisting of approximately problem in tracheal reconstruction has been infection and seven to eight rings was resected. During the procedure, resultant extrusion of the graft. The main source of infec- after incising the trachea above and below, the endotration is contamination from the trachea either at the time cheal tube was withdrawn momentarily, the ringed PTFE of initial implantation or subsequent to it. Unfortunately, graft was placed in the defect, and the endotracheal tube this contamination cannot be avoided. was reinserted through the graft segment in the lower The main complication of the prosthetic materials has portion of the trachea. Anesthesia was continued until the been erosion into the surrounding vital vascular struc- anastomoses were completed. Ringed PTFE grafts 16 to 20 mm in diameter were used. The anastomoses were From the Departmentsof Surgeryand Pathology,State Universityof performed with 3-0 prolene sutures. The rings covering New YorkHealthScienceCenterat Brooklyn,Brooklyn,New York. the graft were made of fluorinated ethylene propylene. Requests for reprints shouldbe addressedto AshokShaha, MD, Fourteen dogs were included in this second portion of the Box40, Departmentof Surgery,State Universityof New YorkHealth experiment (Figures 2 and 3). ScienceCenter,450 ClarksonAvenue,Brooklyn,New York 11203. In both parts of the experiment, each dog was given Presentedat the 34th AnnualMeetingof the Societyof Head and Neck Surgeons,New Orleans,Louisiana,May 22-26, 1988. 1 g of cephalosporin preoperatively. All the dogs were
D
306
THE AMERICAN JOURNAL OFSURGERY VOLUME156 OCTOBER1988
9 .-."
~ 9
I +.
.':-
.
.
.
.
,.'
J
~j
Figure 1. The tracheal window Involving six to seven rings. Patch graft performed with polytetrafluoroethylene.
Figure 2. Segmental resection and reconstruction with ringed polytetrafiuoroethylene InterposlUon graft.
extubated at the conclusion of the experiment and none had tracheostomy. The animals were fed after 12 hours. The dogs were sacrificed 8 to 16 weeks after the procedure, and the tracheas with the grafts were removed and studied histopathologically.
chea was exposed, it was apparent that there was considerable fibrosis around the graft; however, the grafts were not incorporated in the trachea. The grafts appeared to be held in place by the prolene stitches. Histologic study revealed considerable mucosal relining by the epithelium from one cut edge of the trachea to the other. There was also evidence of attempted regrowth of the mucosa over the graft; however, the grafts were not ineorported in the trachea. Fourteen dogs had interposition with ringed PTFE grafts after excising a segment of trachea 7 to 8 rings in length. None of the dogs had air leak, subcutaneous emphysema, or erosion of the prosthesis into the surrounding structures during this part of the experiment. Only one dog died in this group (3 weeks after tracheal reconstruction), presumably due to granulation tissue and narrowing at the anastomotic site. The remaining 13 dogs were
RESULTS Twelve dogs had patch tracheoplasty with PTFE grafts. All did well in the immediate postoperative period. There were no air leaks or subcutaneous emphysema. One dog died suddenly 2 weeks after the operation. Autopsy revealed graft separation and tracheal obstruction due to the presence of graft material in the lumen. One other dog died 289 weeks postoperatively due to wound infection and graft separation. Thus, 10 dogs did well and portions of their tracheas were removed 8 to 16 weeks postoperatively to evaluate graft status. When the tra-
THE AMERICANJOURNALOF SURGERY VOLUME156 OCTOBER1988 307
SHAHA ET AL
Figure 4. AnastomoUc area between the polytetrafluoroethylene graft and trachea.
tion and had no airway problems, None of them required tracheostomy and none had difficulty in swallowing.
Figure 3. Ringed polytetrafluoroethylene graft In place after segmental resection of the trachea.
TABLE I
Ideal Prosthetic Material for Tracheal Reconstruction 1. 2. 3. 4. 5. 6. 7. 8.
Inert Growth of tissue into the graft Should not collapse Development of mucosal lining (?) Air tight Long-term success Not too rigid to erode into surrounding structures Resists infection and extrusion
sacrificed 10 to 16 weeks later and their graft-trachea anastomoses were studied histopathologically. As with the window group, the grafts were not incorporated in the trachea. Instead, they were held to the trachea only by the prolene stitches. There was evidence of attempted mucosal relining at the area of the graft-trachea anastomosis, however, this extended only over a very short area of graft. The remaining portion of the graft from one end to the other had no mucosal lining. Some granulation tissue at the anastomotic site was also seen, but the narrowing did not result in any airway problems (excluding the dog mentioned earlier) (Figure 4). It is important to note that all the dogs tolerated both procedures well and there were no early postoperative problems. The dogs were extubated soon after the opera308
THE AMERICAN JOURNAL OFSURGERY
COMMENTS If a small segment of the trachea is to be resected, reconstruction can be performed by primary anastomoses after mobilizing the trachea. Approximately five to six rings of the trachea can be removed and the cut ends reapproximated. The success rate of this technique is excellent. The technique was perfected by Grillo [8-10], who reported a large series of patients who underwent resection and primary anastomosis of the trachea. However, problems appear when a large segment of the trachea must be resected. Even though there are few indications for such an extensive tracheal resection, reconstruction under such circumstances is always difficult and frought with major complications. An ideal tracheal prosthesis should be inert and airtight (Table I). It should be rigid enough that it does not collapse and, at the same time, should not erode into the surrounding vital structures. It should be incorporated into the surrounding tissues and provide long-term success. Despite the fact that investigators have tried to find an ideal prosthesis for the past half century, no perfect prosthesis is currently available. Long-term problems remain. The silicone tracheal prosthesis described by Neville [6,7] has had limited success. The two major problems associated with prosthetic tracheal reconstruction are infection and extrusion of the graft. From a clinical standpoint, this complication is generally fatal. PTFE grafts have been used routinely for arteriovenous fistulas with excellent results. Although we have seen a number of infected grafts in intravenous drug abusers, these infections have not been major problems and extrusion of'the grafts, even in the presence of infection, has been rare. Using the same principle, we have used the PTFE graft for tracheal reconstruction in the form of a patch or a segment. The rings made of fluorinated ethylene propylene are noncollapsible. The early results of our study are quite promising. The dogs appeared to tolerate the procedure very well with few major postoperative problems over a follow-up period of 3 to 4 months. Whether this has any long-term implications is difficult to predict at this
VOLUME 156
OCTOBER 1988
PROSTHETIC RECONSTRUCTION OF THE TRACHEA
time; however, the fact that an extensive segment of trachea was removed and reconstructed is very exciting. Although PTFE grafts did not become incorporated in the tracheal wall, there was considerable fibrosis around the trachea. The question regarding a need for the development of a mucosal lining in the entire length of the tracheal prosthesis has not been clearly answered [5]. In dogs with patches, there was an attempt at reepithelialization from one cut edge of the trachea to the other. Although it was apparent that small defects were reepithelialized from surrounding mucosal growth, there was no mucosal lining on the interposition grafts, even though there was some attempt at epithelialization near the graft-trachea anastomosis. However, this lack of mucosal lining did not seem to cause any major functional problems, at least during the 3- to 4-month observation period. There was inflammatory reaction noted at the site of graft anastomosis with minimal granulation tissue; however, this did not create any practical problems. PTFE grafts appear to be very useful for tracheal reconstruction and quite promising when used in the forms of a patch and segment. Future research should be
directed to studying the long-term effects of tracheal reconstruction. REFERENCES 1. Maassen W, Greschuchna D, Vogt-Moykopf I, Toomes H, Lullig H. Tracheal resection: state of the art. Thorac Cardiovasc Surg 1985; 33: 2-7. 2. Habal D, Pizzoferrato A, Vespucci A. Prosthetic replacement of large defects of the cervical trachea in dogs. Biomaterials 1985; 6: 17. 3. Scherer MA, Ascheri R, GeissdSrfer K, et al. Experimental bioprosthetic reconstruction of the trachea. Arch Otorhinolaryngol 1986; 243: 215-23. 4. Toomes H, Mickisch G, Vogt-Moykopf I. Experiences with prosthetic reconstruction of the trachea and bifurcation. Thorax 1985; 40: 32-7. 5. Vos GA, Patka P, Klein C, Hoitsma H, Degroot K. Tracheal reconstruction with hydroxyapatite tracheal prosthesis. Life Support Syst 1986; 4: 283-7. 6. Neville WE, Bolanowski PJ. Tracheal reconstruction. Surg Annu 1979; 11: 225-47. 7. Neville WE. Prosthetic reconstruction of trachea. Laryngol Otol Rhinol 1982; 103: 153-4. 8. Grillo HC. Tracheal surgery. J Thorac Cardiovasc Surg 1983; 17: 67-77. 9. Grillo HC, Zannini P, Michelassi F. Complications of tracheal reconstruction. J Thorac Cardiovasc Surg 1986; 91: 322-8. 10. Grillo HC. Tracheal tumors: surgical management. Ann Thorac Surg 1978; 26:112-25.
EDITORIAL COMMENT Mukund S. Didolkar, MD, Baltimore,Maryland
The trachea imposes a formidable challenge when resected and anastomosed. Nearly half its length can be resected and anastomosed without using prosthetic material for most common indications such as tracheal stenosis after prolonged intubation or tracheostomy and resection of primary or metastatic tumors. On occasion, mobilization of tracheal segments is difficult, and rarely more than half the length of trachea needs to be resected. Such rare situations necessitate the use of tracheal prostheses. Since the beginning of this century, several metal and synthetic materials have been used in experimental and clinical situations. Bioprosthetie materials with allografts and xenografts have also been used recently. For successful tracheal prosthetic reconstruction, the material should From the Department of Surgeryl University of Maryland, Baltimore, Maryland.
have the following qualities: airproof seal; good tissue tolerance with minimal reaction; resistance to infection and incrustation; surface epithelialization; mechanical stability; no toxicity; biocompatibility, and nonimmunogenicity. The authors of the preceding study used polytetrafluoroethylene (PTFE) grafts, a widely used material in vascular surgery, for tracheal reconstruction in a canine model. Although tissue tolerance and air-proof quality were excellent in their experiment, surface epithelialization and incorporation into the tissue was not noted. In a vast vascular surgery experience, resistance to infection in an infected field has not been noted; therefore, if PTFE grafts are used in clinical situations for tracheal reconstruction, the bronchopulmonary bacterial flora would easily infect the graft. The sequellae of infection, ineluding bleeding, erosion of neck or thoracic vessels, graft extrusion, and
THE AMERICAN JOURNAL OF SURGERY
pulmonary infection, would readily follow. The authors have a follow-up of 3 to 4 months only, which is a rather short period of time to see such life-threatening complications. The most commonly used silicone prosthesis, which was described by William Neville [1,2] has not gained popularity because of long-term problems. The application of the bioprosthetic material described by Scherer et al [3] may need to be explored more than PTFE or other synthetic materials in the future. Osteomyocutaneous flaps could also be considered for tracheal reconstruction. 1. Neville WE, Bolanowski PJ. Tracheal reconstruction. Surg Annu 1979; 11: 225-47. 2. Neville WE. Prosthetic reconstruction of trachea. Laryngol Otol Rhinol 1982; 103: 153-4. 3. Scherer MA, Ascherl R, GeissdSrfer K, et al. Experimental bioprosthetie reconstruction of the trachea; Arch Otorhinolaryngol 1986; 243: 215-23.
VOLUME !56
OCTOBER 1988
309