HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Head, H. D. Articles by Brown, M. F. Search for Related Content PubMed PubMed Citation Articles by Head, H. D. Articles by Brown, M. F.

Ann Thorac Surg 1995;59:144-148
© 1995 The Society of Thoracic Surgeons

Preoperative Vein Mapping for Coronary Artery Bypass Operations

Miami Valley Hospital and Wright State University, Dayton, Ohio

Accepted for publication July 22, 1994.

	Abstract

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
High-resolution, real-time ultrasonographic imaging of the greater saphenous veins was performed preoperatively in 100 patients undergoing coronary artery bypass grafting. Vein diameters were measured by ultrasound at four locations in the leg, and the course of the vein in the leg was marked on the overlying skin. Veins removed at operation were measured at the same locations at initial dissection and after vein preparation. The mapped and in situ vein diameters correlated closely, whereas the distended vein diameter was approximately 1.5 mm larger. When greater saphenous veins were absent or diseased, lesser saphenous veins were mapped. No differences in measurements were demonstrated for a variety of patient and operator variables. Major branches or duplications were predicted correctly in 11 patients and venous disease in 13 patients. Mapping influenced the surgeon's choice of the venectomy site in 13 patients. Vein mapping is a simple, accurate, and noninvasive method of imaging the saphenous vein preoperatively. It is useful in demonstrating areas of venous anomalies and disease, and predicts the course of the vein in the leg.

	Introduction

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
The greater saphenous vein has been used widely in coronary artery bypass grafting for more than 25 years. Although inferior to the mammary artery graft in late patency, the saphenous vein is readily available, suitable in size and quality for coronary artery bypass grafting, and has well-known early and late graft patency results. Despite these attributes the saphenous vein may not be ideal in all patients. Duplicate systems, large major branches, or small diameter segments may render portions of the saphenous vein smaller than anticipated. Varicosities and phlebosclerosis may cause some veins to be suboptimal for venous transplantation. Difficulties in locating the saphenous vein in the thigh, particularly in obese patients, may lead to extensive dissection and the creation of tissue flaps with attendant wound complications.

Noninvasive imaging of the greater saphenous vein using real-time B-mode ultrasonography can predict anatomic variations in the vein and demonstrate underlying disease and small diameter segments. Such information can be used preoperatively to select which leg and which segments of vein are best suited to saphenous venectomy for grafting. Ultrasonography can also map the course of the vein in the leg, thereby facilitating rapid and accurate location of the saphenous vein at operation.

	Material and Methods

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
The study group consisted of 100 consecutive patients who underwent preoperative vein mapping and coronary artery bypass grafting at a single institution from May through September 1993. Preoperative vein mapping was performed on all patients scheduled for coronary artery bypass grafting with the exception of those undergoing emergency revascularization.

Vein mapping was accomplished by B-mode, real-time ultrasonographic imaging using a BioSound 2000 duplex scanner with an 8-MHz transducer (BioSound, Inc, Indianapolis, IN). Examinations were performed by experienced vascular technologists and whenever possible, were in the vascular laboratory. The patient was positioned supine with a 10 degree reverse Trendelenberg tilt. The leg was flexed slightly at the hip and knee, and externally rotated to approximate the position of the leg at operation. The knee was supported with a rolled pad. Patency of the deep femoral and popliteal veins was confirmed by ultrasonography. If deep venous thrombosis was found, the study was terminated. Patency of the common femoral artery was also confirmed. Mapping of the greater saphenous vein was begun by imaging the vein at the ankle and proceeding proximally. The internal diameter of the vein was measured electronically at multiple sites and recorded on a standardized diagram (Figs 1, 2). The location of the vein was indelibly marked with a continuous line on the skin. If the vein was small (less than 2 mm) or poorly imaged, a dotted line was used. Duplicate venous systems or large, major tributaries were marked on the skin, and noted on the diagram. If the vein branched at the calf, both branches were imaged and the larger vein was marked and measured. Notation was also made of the presence and location of thrombus, large valves, or varicosities. Both legs were mapped unless the entire vein had been removed previously from one or both legs. If the greater saphenous vein had been excised previously or used for peripheral vascular reconstruction, the lesser saphenous veins or arm veins were mapped using similar technique. If the patient could not be transported to the vascular laboratory for the examination, a portable supine study was performed at the patient's bedside.

View larger version (159K): [in this window] [in a new window]   Fig 1. . Ultrasound image of a normal greater saphenous vein 2 inches above the knee. The skin is at the top of the image, and the depth of the vein is indicated by the scale at the right. Cursors have been placed to mark the internal diameter of the vein (two white crosses), which is displayed as Distance = .35 CM). The superficial fascia is seen as a horizontal white line across the fatty areolar tissue of the leg anterior to the vein. (Static image made with ATL Ultramark 9, L10-5 [7.5 MHz] transducer and Sony camera, Advanced Technology Laboratories, Bothell, WA.)

View larger version (35K): [in this window] [in a new window]   Fig 2. . Diagram used for illustrating vein mapping. The course of the greater/lesser saphenous veins and any major branches or duplications are drawn in red ink on the diagram, and vein measurements are noted beside the diagram at corresponding levels. Notations concerning bedside studies, supine positioning, arterial screening, venous anomalies, varicosities, or disease are made in the margins. (ATV = anterior tibial vein; CIV = common iliac vein; CFV = common femoral vein; DFV = deep femoral vein; GSV = greater saphenous vein; IVC = inferior vena cava; LSV = lesser saphenous vein; PER = perforating vein; POP = popliteal vein; PTV = posterior tibial vein; SFV = superficial femoral vein.)

All saphenous venectomies were performed by experienced surgeon's assistants. As vein mapping had been performed routinely at the study institution since August 1990, preoperative imaging was used confidently to predict the side and location of better vein segments, and therefore, the vein was excised from these locations. The skin was incised along the line marking the location of the vein. The vein was then dissected in the soft tissues with as little disturbance as possible. The external diameter of the vein was measured using sterile Castroviejo calipers at the sites marked by cross-hatching. This initial in situ measurement was made before handling the vein to avoid spasm. After recording the in situ measurement, the vein was marked at this site using a surgical marking pen. This mark was placed on the vein to permit remeasurement at the same site after preparation of the vein. The depth of the vein was also measured from the skin surface using a sterile ruler. Side branches all were ligated and divided, and the vein was excised. The vein was distended gently with a buffered crystalloid solution. The external diameter of the distended vein was then measured at the marked sites using the same calipers. Notation was made of any significant operative findings, including duplicate systems, major branches, varicosities, or grossly evident phlebosclerosis.

Measurements of the vein made by preoperative ultrasound imaging were compared with those made in situ at operation and those made after vein preparation. These comparisons were analyzed to determine if the following factors contributed to discrepancies between imaged measurements and operative measurements: supine positioning of the leg, obesity, depth of the vein, diabetes mellitus, and intravascular volume status at time of operation reflected by central venous pressure and pulmonary artery wedge pressure. Comparisons were also made among measurements obtained by individual vascular technicians and individual surgeon's assistants. Data analysis was performed using a computerized statistics program (Macintosh SYSTAT, Evanston, IL).

	Results

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
The diameter of the vein predicted by ultrasonographic imaging (3.57 ± 1.03 mm) correlated closely with that measured in situ at operation (3.82 ± 1.08 mm). Although not statistically significant, this slightly larger in situ measurement may reflect comparison of the internal diameter measured by ultrasonography to the external diameter measured at operation. The diameter of the prepared, distended vein was approximately 1.5 mm larger than either the imaged or the in situ measurements (5.25 ± 1.08 mm). The diameter of the vein increased from ankle to thigh; however, the same relationship between measurements was observed regardless of the imaged size of the vein (Fig 3). Actual vein diameters were rarely smaller than predicted by mapping.

View larger version (29K): [in this window] [in a new window]   Fig 3. . Comparison of mean diameters of greater saphenous veins obtained by preoperative ultrasonographic imaging (Mapped), operative measurement before manipulation (``In Situ''), and measurement after excision and preparation (Distended). Vein diameters are displayed at defined locations in the leg and are shown to increase progressively from ankle to upper thigh. Mapped diameters correlate closely with those measured in situ, and the distended vein diameters are generally 1.5 mm greater than the mapped and in situ diameters.

Major branches or duplicate systems were imaged in 11 patients, and venous disease was shown in 13 patients (phlebosclerosis in 5, varicosities in 5, and thrombus in 3). In 2 patients a major branch was found at operation that had not been shown by preoperative mapping, and a varicosity was found in another patient that had not been noted by ultrasonography. Preoperative mapping was directly responsible for the surgeon's choice of the venectomy site in 13 patients. The vein was predicted to be larger or more uniform in size in one leg compared with the other in 8 patients, and varicosities, anomalies, or disease influenced this choice in 5 patients. At least a segment of the saphenous vein from one or both legs had been removed previously in 12 patients. The lesser saphenous veins were mapped in 3 of these patients, and were mapped in 8 other patients because of the presence of small or diseased greater saphenous veins. The lesser saphenous vein was used at operation in 1 patient. A Baker's cyst was discovered incidentally by preoperative ultrasonography in 1 patient.

	Comment

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
Although the greater saphenous vein has been used extensively in coronary artery bypass grafting, generally assessment of the vein has not been performed preoperatively except by crude physical examination. Until recently imaging techniques were invasive, attended by potential complications, and were often inaccurate or incomplete. Furthermore, as the saphenous vein was easily accessible in most patients, and as additional veins could be obtained from the same or opposite leg if unsuitable areas of vein were encountered, there was little demand for preoperative venous studies. Unfortunately this lack of preoperative information concerning the anatomy, location, and size of the vein can contribute to problems at operation. Excessive dissection is sometimes performed in attempts to locate the vein, especially in an obese thigh. This results in greater soft tissue injury and creation of tissue flaps that can lead to wound complications. Such inaccurate dissection may also predispose the vein to greater and rougher handling during its excision. Small diameter segments or diseased portions of the vein are also encountered, requiring further time and dissection to locate and harvest additional vein suitable for grafting. When this requires the removal of vein from the opposite leg, it is sometimes observed that the additional vein was of better size and quality than the originally selected vein.

Assessment of the greater saphenous vein has been performed previously using venography [1–8]. This has proven accurate in depicting venous anatomy, but unreliable in predicting vein diameter because of contrast filling from the superficial to the deep venous system. As the technique is two-dimensional, it is a poor predictor of vein depth and location [1]. Venography is generally safe but has been associated with local tissue necrosis, renal failure, and anaphylactic shock. Tissue irritation has been less common with the development of low osmolality contrast [2]. Venography is an invasive procedure and must be performed in the radiology department.

Venous imaging has been performed more recently using high-resolution, real-time, B-mode ultrasonography. The technique is accurate in imaging the saphenous vein and in depicting its anatomy, major branching, or other variants including duplicate systems and narrow segments, valves and large varicosities, or other underlying venous disease. Using internal calipers, ultrasonography has been used to predict the diameter of venous segments that are too small to allow successful arterial reconstruction. The course of the vein in the leg can be imaged and traced on the skin, and the depth of the vein can be predicted. As ultrasonography equipment is portable, examinations can be performed either in the vascular laboratory or at the bedside.

Although ultrasonographic vein mapping has been available for coronary artery bypass grafting, it has been used much more frequently in patients requiring infrainguinal arterial reconstruction, especially for in situ grafting [1, 9–14]. Although most saphenous veins are suitable for such grafting, small size (vein diameter, less than 2 mm) precludes successful arterial reconstruction in approximately 10% of veins [3, 9]. Another 12% of the veins are poorly suited for grafting because of the presence of underlying disease including phlebosclerosis and varicosities [15]. Veins predicted to be suitable for grafting based on vein diameter greater than 2 mm and absence of varicosities, thrombus, or phlebosclerosis have been successfully used in 93% or more of patients [9, 11]. Small vein size or underlying venous disease predictive of unsuitability has been confirmed at operation in all, but nonetheless, successful grafting has been accomplished in a few of these patients. Anatomic variants are common and may produce segments of smaller diameter vein. Duplicate or ``split'' veins are found in about 10% of patients, usually below the knee, and major branches are often encountered in the thigh [1, 4, 5, 9]. Although anatomically normal, the course of the vein is more lateral than expected in about 5% of the patients [5].

Preoperative vein mapping has rarely been reported in patients undergoing coronary artery bypass grafting. Lemmer and colleagues [16] used preoperative vein mapping selectively in 8 of 390 patients undergoing coronary artery bypass grafting. Mapping was performed in these patients because of obesity or previous stripping or other operation involving the greater saphenous veins. Two patients were denied operation on the basis of absence of any suitable veins in the greater or lesser saphenous distribution by mapping.

If the greater saphenous vein is absent or is diseased or small, the lesser saphenous vein can be mapped. This vein has been imaged by preoperative ultrasonography, and has been found to be suitable for vascular operations in about 90% of the patients [17–20]. A high termination of the vein medial to the posterior knee crease has been predicted accurately by mapping in 8% of the patients [17]. When both greater and lesser saphenous veins are unsuitable for grafting, the arm veins can be imaged successfully by ultrasonography [21].

In patients who have previously undergone coronary artery bypass grafting, occasionally it is useful to map the previously operated leg in addition to the opposite greater saphenous vein or the lesser saphenous veins. One patient in our experience had previously undergone removal of the saphenous vein from the thigh for coronary artery bypass grafting. Preoperative mapping, however, revealed the unsuspected presence of a good quality greater saphenous vein in this area, and indeed this was confirmed at reoperation. It is likely that a large branch or ``accessory'' saphenous vein had actually been used at this patient's first operation.

The technique of vein mapping is critical to its success. An 8-MHz transducer produces clear venous images to a depth of 4 cm, but a 7- or 7.5-MHz transducer may be required to provide imaging at greater depths from the skin in especially obese patients. To map accurately the location of the underlying vein on the skin, it is important to image the vein with the leg positioned as it will be at operation. Therefore, mapping of the greater saphenous vein is performed with the leg externally rotated and the knee flexed and supported on a pillow. This ensures that the course of the vein marked on the skin will correspond to the actual location of the vein when the leg is similarly positioned at operation. Venous filling is also helpful for optimal imaging, and this is facilitated by scanning with at least 10° of reverse Trendelenberg using a tilt table. Nonetheless, bedside scanning with the patient in a flat, supine position has provided satisfactory results in this study. Although the angle and the Doppler signal of the 8-MHz transducer are not suitable for detailed arterial examination, patency screening of the femoral artery can be assessed accurately at the time of venous mapping. A practiced vascular technician can complete a mapping study of both legs in about 30 minutes. Outpatient vein mapping can be performed along with other preadmission laboratory tests. If this is done several days preoperatively, the patient can be given a marking pen to ``touch-up'' the skin line after bathing. The total costs of the examination average less than $100, and hospital charges for the procedure have been reimbursed.

Although this study demonstrates that preoperative vein mapping by ultrasound predicts accurately the location, anatomy, size, and underlying disease of the saphenous veins, the impact of preoperative mapping on leg wound complications was not studied separately. It is our definite impression and that of the surgeon's assistants at this institution, however, that the routine use of preoperative vein mapping has reduced appreciably the incidence of postoperative leg wound complications including flaps, hematomas, and infections. Indeed no significant leg wound complication occurred during this study. Seeger and colleagues [13] noted a 2% incidence of leg wound complications during the year in which vein mapping was studied, compared with a 17% incidence of complications the preceding year. Leg wound complications occur more commonly in obese female patients in whom the vein below the knee is often of poor quality and in whom the vein in the thigh is more difficult to locate resulting in more tissue dissection and creation of flaps [22]. Such difficult vein exposure and dissection is important because even minimal trauma to the vein can result in significant endothelial damage that can affect graft patency adversely [23]. In our experience with preoperative vein mapping, the location of the vein can be predicted accurately, thereby avoiding extensive dissection and flaps.

	Acknowledgments

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
We acknowledge Nancy Roy, RVT, for her invaluable assistance in developing the techniques of ultrasound imaging used in this study, and her and the vascular laboratory staff for the mappings performed in the study patients. We also acknowledge Patrick J. Cullen, PA-C, David S. Lewis, PA-C, Christopher P. Padgett, PA-C, and Brian S. Allhouse for their assistance and patience in obtaining operative measurements of the veins.

	Footnotes

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 
Address reprint requests to Dr Head, Valley Cardiovascular and Thoracic Surgeons, Suite 6257, 30 Apple St, Dayton, OH 45409.

	References

Top Footnotes Abstract Introduction Material and Methods Results Comment Acknowledgments References

 

1. Leopold PW, Shandall AA, Corson JD, Shah DM, Leather RP, Karmody AM. Initial experience comparing B-mode imaging and venography of the saphenous vein before in situ bypass. Am J Surg 1986;152:206–10.[Medline]
2. Lea Thomas M, Posniak HV. Saphenography. AJR 1983;141:812–4.[Free Full Text]
3. Mosley JG, Manhire AR, Raphael M, Marston JAP. An assessment of long saphenous venography to evaluate the saphenous vein for femoropopliteal bypass. Br J Surg 1983;70:673–4.[Medline]
4. Burnand KG, Senapati A, Lea Thomas M, Browse NL. A comparison of preoperative long saphenous phlebography with operative dissection in assessing the suitability of long saphenous vein for use as a bypass graft. Ann R Coll Surg 1985;67:183–6.
5. Shah DM, Chang BB, Leopold PW, Corson JD, Leather RP, Karmody AM. The anatomy of the greater saphenous venous system. J Vasc Surg 1986;3:273–83.[Medline]
6. MacFarlane R, Godwin RJ, Barabas AP. Are varicose veins and coronary artery bypass surgery compatible? Lancet 1985;2:859.
7. Ruben GD, Goldberg SE, Cope C, Cohen EA, Township B. Preoperative angiographic assessment of saphenous vein for arterial bypass surgery. J Med Soc NJ 1985;82:651–3.
8. Veith FJ, Moss CM, Sprayregen S, Montefusco C. Preoperative saphenous venography in arterial reconstructive surgery of the lower extremity. Surgery 1979;85:253–6.[Medline]
9. Ruoff BA, Cranley JJ, Hannan LA, et al. Real-time duplex ultrasound mapping of the greater saphenous vein before in situ infrainguinal revascularization. J Vasc Surg 1987;6: 107–13.[Medline]
10. Buchbinder D, Semrow C, Friedell ML, Ryan T, Calligaro K, Rollins D. B-mode ultrasonic imaging in the preoperative evaluation of saphenous vein. Am Surg 1987;53:368–72.[Medline]
11. Bagi P, Schroeder T, Sillesen H, Lorentzen JE. Real time B-mode mapping of the greater saphenous vein. Eur J Vasc Surg 1989;3:103–5.[Medline]
12. Davies AH, Magee TR, Jones DR, Hayward JK, Baird RN, Horrocks M. The value of duplex scanning with venous occlusion in the preoperative prediction of femoro-distal vein bypass graft diameter. Eur J Vasc Surg 1991;5:633–6.[Medline]
13. Seeger JM, Schmidt JH, Flynn TC. Preoperative saphenous and cephalic vein mapping as an adjunct to reconstructive arterial surgery. Ann Surg 1987;205:733–9.[Medline]
14. Sullivan ED, Peter DJ, Cranley JJ. Real-time B-mode venous ultrasound. J Vasc Surg 1984;1:465–71.[Medline]
15. Panetta TF, Marin ML, Veith FJ, et al. Unsuspected preexisting saphenous vein disease: an unrecognized cause of vein bypass failure. J Vasc Surg 1992;15:102–12.[Medline]
16. Lemmer JH, Meng RL, Corson JD, Miller E. Preoperative saphenous vein mapping for coronary artery bypass. J Cardiac Surg 1988;3:237–40.[Medline]
17. Chang BB, Paty PSK, Shah DM, Leather RP. The lesser saphenous vein: an underappreciated source of autogenous vein. J Vasc Surg 1992;15:152–7.[Medline]
18. McShane MD, Smallwood J, Field J, Chant ADB. Early experience with B mode ultrasound mapping of the long saphenous vein prior to femorodistal bypass. Ann R Coll Surg 1988;70:147–9.
19. Raess DH, Mahomed Y, Brown JW, King RD. Lesser saphenous vein as an alternative conduit of choice in coronary bypass operations. Ann Thorac Surg 1986;41:334–6.[Abstract]
20. Weaver FA, Barlow R, Edwards WH, Mulherin JL, Jenkins JM. The lesser saphenous vein: autogenous tissue for lower extremity revascularization. J Vasc Surg 1987;5:687–92.[Medline]
21. Salles-Cunha SX, Andros G, Harris RW, Dulawa LB, Oblath RW. Preoperative noninvasive assessment of arm veins to be used as bypass grafts in the lower extremities. J Vasc Surg 1986;3:813–6.[Medline]
22. DeLaria GA, Hunter JA, Goldin MD, Serry C, Javid H, Najafi H. Leg wound complications associated with coronary revascularization. J Thorac Cardiovasc Surg 1981;81:403–7.[Abstract]
23. Adcock OT, Adcock GLD, Wheeler JR, Gregory RT, Snyder SO, Gayle RG. Optimal techniques for harvesting and preparation of reversed autogenous vein grafts for use as arterial substitutes: a review. Surgery 1984;96:886–93.[Medline]

This article has been cited by other articles:

				H. Luckraz, J. Lowe, N. Pugh, and A. A. Azzu Pre-operative long saphenous vein mapping predicts vein anatomy and quality leading to improved post-operative leg morbidity Interactive CardioVascular and Thoracic Surgery, April 1, 2008; 7(2): 188 - 191. [Abstract] [Full Text] [PDF]

				J. D. Cohn and K. F. Korver Selection of Saphenous Vein Conduit in Varicose Vein Disease Ann. Thorac. Surg., April 1, 2006; 81(4): 1269 - 1274. [Abstract] [Full Text] [PDF]

				J. D. Cohn and K. F. Korver Optimizing Saphenous Vein Site Selection Using Intraoperative Venous Duplex Ultrasound Scanning Ann. Thorac. Surg., June 1, 2005; 79(6): 2013 - 2017. [Abstract] [Full Text] [PDF]

				C. P. Cruz, J. F. Eidt, A. T. Brown, and M. Moursi Correlation Between Preoperative and Postoperative Duplex Vein Measurements of the Greater Saphenous Vein Used for infrainguinal Arterial Reconstruction Vascular and Endovascular Surgery, January 1, 2004; 38(1): 57 - 62. [Abstract] [PDF]

				J. A. Lamphere, P. O. Daily, R. J. Moreno, S. Marcus, W. P. Dembitsky, R. M. Adamson, M. Burr, and P. O'Neill New Technique for Lesser Saphenous Vein Harvesting Ann. Thorac. Surg., December 1, 1995; 60(6): 1829 - 1830. [Abstract] [Full Text]

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Head, H. D. Articles by Brown, M. F. Search for Related Content PubMed PubMed Citation Articles by Head, H. D. Articles by Brown, M. F.