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Soft moldable universal tunneler in bypass surgery for lower limb ischemia

Abstracts

Background: Bypass surgery for lower limb ischemia involves the creation of a tunnel for accommodating the vascular graft. Tunnel shape and length depend on the site chosen for proximal and distal anastomosis. Tunnelers currently employed are rigid metallic cylindrical structures. Objective: To test the use of a moldable universal metallic tunneler in bypass surgeries for lower limb ischemia. Methods: The assessed tunneler is a hybrid, modular, cylindrical structure made of moldable stainless steel wire, with a handle on the proximal end, a tapered distal tip with two interchangeable diameter options on the distal end, and an outer cylindrical polyethylene sheath. The same tunneler was used in all bypass surgeries for lower limb ischemia, regardless of type, shape, and length of the graft chosen. Results: Tunneler moldability and deformation capacity made it possible to adapt and use the same device in combination with several different types of grafts. The tapered distal tip with two diameter options allowed the tunneler to be used in surgeries performed with both reversed saphenous vein and synthetic graft. Conclusion: The soft moldable universal tunneler tested in this study can be used safely and proved beneficial in bypass surgeries for lower limb ischemia. The versatility and low production cost involved may lead to replacement of the rigid tunnelers currently employed.

Graft; lower limb; bypass; ischemia


Contexto: A revascularização do membro inferior isquêmico envolve a criação de túnel para a acomodação do enxerto vascular cujo trajeto e extensão dependem do local da anastomose proximal e distal do enxerto. Na atualidade, os tunelizadores utilizados consistem em estruturas cilíndricas metálicas rígidas. Objetivo: Testar a utilização de um tunelizador universal metálico e moldável na revascularização de membros inferiores isquêmicos. Métodos: O tunelizador desenvolvido consiste de uma estrutura cilíndrica híbrida e modular composta de fio de aço inoxidável moldável interno, com manopla em extremidade proximal, dupla ponta cônica intercambiável em extremidade distal e bainha cilíndrica externa de polietileno. O tunelizador foi utilizado em cirurgias de revascularização do membro inferior isquêmico, independentemente do tipo, trajeto e extensão do enxerto escolhido. Resultados: As características de maleabilidade e capacidade de deformação permitiram a adaptação e utilização do mesmo tunelizador nos diversos tipos de enxerto realizados. A ponta cônica distal com duplo diâmetro, intercambiável, permitiu que o mesmo aparato pudesse ser utilizado na cirurgia de revascularização com veia safena reversa ou prótese sintética. Conclusão: O tunelizador metálico maleável moldável pode ser utilizado com segurança e apresenta vantagens nas cirurgias de revascularização dos membros inferiores isquêmicos e possivelmente em outros territórios vasculares isquêmicos. Sua versatilidade e baixo custo de produção podem levá-lo a substituir os tunelizadores rígidos utilizados na atualidade.

Enxerto; membro inferior; ponte; isquemia


ORIGINAL ARTICLE

Soft moldable universal tunneler in bypass surgery for lower limb ischemia

Fabio Henrique RossiI; Nilo Mitsuru IzukawaI; Lannes Alberto OliveiraI; Wilson TrópicoI; José Nicodemos TobiasII; Akash Kuzhiparambil PrakasanI; Heraldo Antônio BarbatoI

IDepartamento de Cardiologia, Instituto Dante Pazzanese de Cardiologia (IDPC), São Paulo, SP, Brazil

IIDepartamento de Bioengenharia, IDPC, São Paulo, SP, Brazil

Correspondence

ABSTRACT

Background: Bypass surgery for lower limb ischemia involves the creation of a tunnel for accommodating the vascular graft. Tunnel shape and length depend on the site chosen for proximal and distal anastomosis. Tunnelers currently employed are rigid metallic cylindrical structures.

Objective: To test the use of a moldable universal metallic tunneler in bypass surgeries for lower limb ischemia.

Methods: The assessed tunneler is a hybrid, modular, cylindrical structure made of moldable stainless steel wire, with a handle on the proximal end, a tapered distal tip with two interchangeable diameter options on the distal end, and an outer cylindrical polyethylene sheath. The same tunneler was used in all bypass surgeries for lower limb ischemia, regardless of type, shape, and length of the graft chosen.

Results: Tunneler moldability and deformation capacity made it possible to adapt and use the same device in combination with several different types of grafts. The tapered distal tip with two diameter options allowed the tunneler to be used in surgeries performed with both reversed saphenous vein and synthetic graft.

Conclusion: The soft moldable universal tunneler tested in this study can be used safely and proved beneficial in bypass surgeries for lower limb ischemia as well as in other ischemic vascular territories. The versatility and low production cost involved may lead to replacement of the rigid tunnelers currently employed.

Key-words: Graft, lower limb, bridge, ischemia.

Introduction

Ischemic lower limb bypass surgery involves the creation of a tunnel for placing the vascular graft, either it is done with the great reversed saphenous vein or synthetic prosthesis. The pathway and the extension of the tunnel depend on the position of the arterial segment chosen for the performance of the graft's proximal and distal anastomoses. The confection of these tunnels and the passage of the graft through them are frequently performed blindfold. It is likely that, despite the scarcity of the literature on the subject, surgeons have been concerned with this important and delicate surgical time and idealized varied techniques and instruments since the first steps of arterial restoration surgery. Currently tunnelers used consist of rigid metallic cylindrical structures, which may limit or difficult the confection of tunnels and even produce iatrogenic lesions in structures or organs present in the graft's pathway.1,2 The objective of this study was to test the use of a moldable universal metallic tunneler in bypass surgery of lower limb ischemia.

Methods

Soft moldable, and universal metallic tunneler, developed at the Bioengineering Laboratory of the Instituto Dante Pazzanese de Cardiologia, São Paulo (SP), consists of a cylindrical, hybrid and modular structure composed by: 1) a string of internal soft moldable stainless steel, with a handle in proximal end and interchangeable double tapered tip in distal end; 2) transparent polyethylene external cylindrical sheath (Figure 1).


The tunneler was used in bypass surgery for lower limb ischemia in the Vascular Surgery Division of the Instituto Dante Pazzanese de Cardiologia. The same device was used in all the surgeries performed, regardless of the type, pathway, and extension of the graft chosen.

Results

The initial experience obtained with the tunneler was performed in the types of ischemic lower limb bypass grafts described in Table 1.

The features of malleability and deformation capacity of the tunneler (Figure 2) allowed its adaptation and use in the various types of graft performed. The distal tapered tip with interchangeable double diameter allowed the same device to be used in the bypass surgery both with reversed saphenous vein and synthetic prosthesis.


In the case of the reversed great saphenous vein tunneling, the passage of the tunneler between proximal and distal ends is performed in the interior of the polyethylene sheath protections, preventing torsion, stretching and lesion to the lateral collateral branches linkage or nudging.

Discussion

Autogenous or synthetic graft is commonly used in lower limb ischemia. Technical failure is the main cause of early obstruction of the graft, and torsion, traction, stretching, nudging and wearing, the main mechanisms. In addition to the attention at performing the anastomoses, tunneling is a fundamental stage for the surgery's success.

The use of pre-molded rigid tunnelers in predetermined bends might limit its adaptation or even produce lesions to structures and organs present in its pathway.4 Besides that, we know that one of the most feared complications in ischemic limb bypass surgery is the infection of operative wound and of the graft itself. The number of surgical incisions and dissections needed during the graft's tunneling may be involved in this type of complication. The use of the equipment here presented may decrease the number of incisions needed and, probably, the index of surgical infections.

Obstructive atherosclerotic disease is a systemic condition that may affect various arterial territories. The variability of extension, severity and affected territory renders the possibilities of surgical strategies needed infinite, which highlights the importance of features of the moldable and malleable tunneler presented here in the ischemic lower limbs bypass surgery.

The features of the tested tunneler may enable its application in other territories and types of surgery, such as extra-anatomic grafts for supra-aortic trunks (subclavian carotid graft, carotid-carotid graft and axillary-axillary graft), supradiafragmatic aortic derivations for visceral arteries and iliac temporary conduits tunneling in endovascular treatment of aortic diseases, arteriovenous fistulas, etc.

Conclusion

Soft moldable metal tunneler may be safely used and presents vantages in ischemic lower limbs bypass surgeries and possibly in other ischemic vascular territories. Its versatility and low production cost may lead it to replace rigid tunnelers currently used.

References

  • 1. Parsonnet V, Driller J. A tunneler for bypass vascular surgery. Arch Surg. 1973;106:236-7.
  • 2. Blumenberg RM, Gelfand ML. A simple and inexpensive tunneler for use in peripheral vascular surgery. Surgery. 1974;75:305-7.
  • 3. Owens CD, Ho KJ, Conte MS. Lower extremity vein graft failure: a translational approach. Vasc Med. 2008;13:63-74.
  • 4. Mouton WG, Otten KT, Fitridge RA. Proximalized lateral tunnel for the bypass to the dorsalis pedis artery: a safe way to go. Thorac Cardiovasc Surg. 2001;49:245-6.
  • Correspondência:
    Fabio Henrique Rossi
    E-mail:
  • Publication Dates

    • Publication in this collection
      01 Sept 2010
    • Date of issue
      2010

    History

    • Accepted
      16 Mar 2010
    • Received
      02 Oct 2009
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