Interact CardioVasc Thorac Surg 2008;7:10-13. doi:10.1510/icvts.2007.164665
© 2008 European Association of Cardio-Thoracic Surgery
Work in progress report - Coronary |
Endoscopic harvesting of saphenous vein with a small caliber
Yoshiharu Soga*,
Michiya Hanyu,
Jota Nakano and
Hitoshi Okabayashi
Department of Cardiovascular Surgery, Kokura Memorial Hospital, 1-1, Kifune-machi, Kokurakita-ku, Kitakyushu 802-8555, Japan
Received 9 August 2007;
received in revised form 23 October 2007;
accepted 24 October 2007
*Corresponding author. Tel.: +81-93-921-2231; fax: +81-93-921-8497.
E-mail address: sogakin{at}dd.iij4u.or.jp (Y. Soga).
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Abstract
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Endoscopic saphenous vein harvesting (ESVH) requires a high degree of technical expertise. However, few studies have investigated the influence of SV caliber on the technical difficulty and outcome of ESVH. We analyzed 86 consecutive patients who underwent ESVH using a VirtuoSaphTM system. SV caliber was measured in the above-knee portion by ultrasound. Patients were then divided into two groups: group A (SV caliber <3 mm, n=16), and group B (the remaining patients, n=70). ESVH procedure time and SV characteristics were compared between the groups. In group A, the SV had a larger number of side branches (11.7±1.2 in A, 9.8±0.4 in B, P=0.043) and required a longer operation time (A, 57.5±3.7 min; B, 43.9±1.9 min, P=0.0024), whereas the time required for endoscopy did not differ. Graft length (A, 27.7±5.0 cm; B, 25.7±3.7 cm) and ratio of repaired side branches (A, 26.6±20.5%; B, 25.7±23.9%) showed no significant differences. ESVH using a VirtuoSaphTM system is feasible, regardless of SV caliber. SV with a caliber of <3 mm has a larger number of side branches, thus prolonging the procedure time.
Key Words: Endoscopic procedure; CABG; Venous grafts
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1. Introduction
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Since the first report by Lumsden and associates [1], saphenous vein (SV) harvest using a video endoscope has been recognized as a useful technique for reducing postoperative wound complications [2–4]. We have been using endoscopic SV harvesting (ESVH) since 2005, when the VirtuoSaphTM ESVH system (Terumo Corp., Tokyo, Japan) came on the market in Japan. In the early period, however, ESVH was found to be a time-consuming procedure in patients with a small-caliber SV; it was more difficult to expose the initial segment via a small skin incision, and a large number of avulsed side branches needed to be repaired. Although the long-term results of ESVH for patients undergoing coronary artery bypass grafting have not yet been reported, SV grafts of less satisfactory quality seem to be associated with poorer long-term patency when used for peripheral artery bypass surgery, because additional manipulation of the vein during the endoscopic procedure may damage the vein graft itself [5–7]. Therefore, we have hypothesized that a SV with a small caliber is less appropriate for ESVH and is better harvested by a conventional open procedure. The aim of this prospective study was to evaluate the influence of SV diameter on the technical difficulty and outcome of ESVH, and to create institutional guidelines for use of the procedure.
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2. Materials and methods
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2.1. Patients
Between October 2005 and December 2006, a total of 125 consecutive ESVH procedures were performed by three surgeons at our institution. Excluding the initial 39 patients to eliminate any effect of inexpertise during the period when ESVH was being introduced, 86 patients were prospectively enrolled for the present study. All the harvested veins were used for elective coronary artery bypass grafting. Written informed consent was obtained from all patients.
2.2. Surgical technique
SV caliber in the above-knee portion was measured using an ultrasound system immediately after induction of general anesthesia and before skin incision. Patients were then divided into two groups: group A (SV caliber <3 mm, n=16), and group B (the remaining patients, n=70). A VirtuoSaphTM ESVH system (Terumo Corp., Tokyo, Japan) was used in all patients. This system has a computer simulator (Fig. 1) to accelerate the speed of learning, and all three surgeons underwent training prior to clinical usage. VirtuoSaphTM has three disposable components – a trocar, dissector, and harvester (Fig. 2), and employs bipolar diathermy, carbon dioxide insufflation, and an endoscope system.
After exposure of the initial segment of the SV via a 2-cm vertical skin incision in the thigh above the knee, the trocar is inserted through the incision overlying the vein in order to prevent CO2 leakage. An endoscope incorporating the dissector is then inserted via the trocar along the tract of the vein and advanced to the groin with the aid of insufflation by CO2, which is blown from the tip of the dissector. Once the vein has been completely exposed, the dissector is removed and the harvester is inserted in its place. The harvester has a V-cutter (bipolar diathermy) arm and a V-keeper arm (Fig. 2) so that side branches of the SV can be cut with one hand. In addition, the harvester has a wiper for the endoscope to maintain a clear view during the procedure. When the SV has been totally mobilized, it is divided and ligated proximally via another 5-mm skin incision at the groin and removed from the leg. Finally, as many of the SV side branches as possible are ligated with 5-0 silk. Avulsed side branches are secured with interrupted 7-0 Prolene (Ethicon, Somerville, NJ) repair sutures. Following deheparinization after the completion of coronary bypass grafting, all wounds are closed in two layers with 3-0 Nylon suture and no suction drains are routinely used.
The ESVH procedure time was recorded for every patient. Total procedure time was defined as the period from skin incision to completion of branch ligation and/or repair. SV characteristics such as the total number of side branches, number of ligated branches, number of repaired branches, and total graft length were also recorded in the operating room.
2.3. Statistical analysis
Patient demographics, procedure time, and SV characteristics were compared between the groups. Statistical analyses were carried out using StatView software version 5.0 (SAS Institute, Inc, Cary, NC). Data are expressed as the mean±S.D. Comparisons of continuous variables were performed using unpaired t-test. Differences at P<0.05 were considered statistically significant.
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3. Results
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There were no significant inter-group differences in patient age (group A, 71.2±8.7 years; group B, 67.3±10.1 years; P=0.159), height (A, 157.3±7.6 cm; B, 159.9±9.2 cm; P=0.299), or weight (A, 55.9±11.8 kg; B, 60.1±11.9 kg; P=0.200). Recorded procedure time and SV characteristics are summarized in Table 1. In group A (SV caliber <3 mm), the SV had a larger number of side branches (A, 11.7±1.2; B, 9.8±0.4; P=0.043), but graft length (A, 27.7±5.0 cm; B, 25.7±3.7 cm) and ratio of repaired side branches relative to total branches per graft (A, 26.6±20.5%; B, 25.7±23.9%) showed no significant inter-group differences. Group A patients required a longer operating time (A, 57.5±14.8 min; B, 43.9±15.9 min; P=0.0024), whereas the time required for the endoscopic part of the procedure (from initial skin incision to vein removal) did not differ between the groups. Multi-row detector computed tomography (MDCT) was done in 55 (64%) of the 86 patients prior to discharge to evaluate the bypass grafts, and this showed 100% patency.
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4. Comment
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The major findings of the present study were that SVs with a small caliber of <3 mm had a larger number of side branches and required a longer operating time than those with a caliber of >3 mm, whereas the time required for the endoscopic part of the procedure did not differ between the two groups. All of the narrow SVs were applicable for coronary artery bypass grafting and were patent postoperatively.
4.1. Endoscopic saphenous vein harvesting (ESVH)
ESVH is known to be a useful technique for attenuating postoperative wound complications, thus shortening the hospital stay and reducing costs [1–4]. Despite these advantages, as well as its cosmetic appeal, however, ESVH is not yet widely performed routinely. One of the major reasons may be that ESVH requires surgical training and a high degree of expertise in order to prepare a SV graft within an acceptable time frame. A learning period is necessary, and experience of 10 to 20 cases per surgeon is considered to be essential [3, 4, 7]. For this reason, we excluded the initial 39 cases, and began this study at the 40th case. In our series, the minimum procedure time was 23 min, and average operating time in the narrow vein group was 57.5 min. Our current strategy for graft choice in patients with triple-vessel coronary artery disease is that the first choice of graft is the bilateral internal thoracic arteries harvested in a skeletonized manner using an ultrasound scalpel for the left coronary artery territory, and the SV is used mainly for the right coronary artery territory as a second or third choice of graft [8]. Therefore, our average procedure time (44 min) for a SV with a caliber of >3 mm seems to be acceptable. Based on our current experience, we consider that ESVH should be indicated for elective patients.
Another factor that may affect long-term graft patency is SV graft quality [5–7]. During ESVH, the vein is typically exposed to more manipulation than during conventional open harvest. With the VirtuoSaphTM ESVH system, as is the case for other endoscopic systems, injury to the vein may occur during the following three different phases of vein harvest, as pointed out by Jordan and coworkers: (i) when the trocar or harvester is first placed into the subcutaneous cavity along the vein tract, (ii) during dissection of the vein with the harvester, and (iii) during retraction of the vein for dissection and removal [5]. Moreover, subclinical vein injury may also play a role in late graft failure. Traumatic injury to the vein has been studied as a potential factor responsible for a delayed neointimal response and graft failure [5]. In our series, the repair ratio (number of repaired side branches/total number of side branches) varied from 0% to 83%. However, as there has been no reported study of the long-term patency of SV grafts harvested using an endoscopic technique in coronary artery bypass patients, careful follow-up will be necessary.
4.2. Saphenous vein with a small caliber
There are few reports on the influence of SV caliber in ESVH. In the present study, SVs with a caliber of <3 mm required a longer procedure time than those measuring 3 mm or more, whereas the time for the endoscopic part of the procedure did not differ. The difference was due to the time required for branch ligation/repair, and also probably the difference in time required for repair of avulsed branches. This can be interpreted as indicating that a SV with a smaller caliber has tinier branches, and that such branches may be easily avulsed during ESVH. Although all of the SVs with a caliber of <3 mm were applicable as graft conduits and were patent in the early postoperative period, such veins should be harvested by an experienced surgeon to ensure repair-less higher-quality grafts.
4.3. Preoperative ultrasound study
The timing of SV caliber measurement may be an additional concern. In the operating room, fasted patients tend to be in a hypovolemic state, and this can lead to underestimation of SV caliber. Therefore, in this series we also measured SV diameter 1 to 3 days before the operation, and no significant differences were detected between the measurements obtained at the two time points. On the other hand, preoperative echo-guided skin marking along the course of the SV is useful, especially in small patients in whom it is more difficult to locate the first segment via a small skin incision. Therefore, we recommend echo-guided skin marking before the patient is brought to the operating room, thus securing more time, because a small SV is sometimes difficult to locate by ultrasound.
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5. Conclusions
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The present study has confirmed that endoscopic SV harvesting using a VirtuoSaphTM system is applicable to all patients regardless of their SV caliber. However, SVs with a caliber of <3 mm have a larger number of side branches, and these prolong the procedure time in comparison with SVs measuring >3 mm in caliber. Such small veins may be better harvested by an experienced surgeon.
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References
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- Lumsden AB, Eaves FF III, Ofenloch JC, Jordan WD. Subcutaneous, video-assisted saphenous vein harvest: report of the first 30 cases. Cardiovasc Surg 1996; 4:771–776.[CrossRef][Medline]
- Davis Z, Jacobs HK, Zhang M, Thomas C, Castellanos Y. Endoscopic vein harvest for coronary artery bypass grafting: technique and outcomes. J Thorac Cardiovasc Surg 1998; 116:228–235.[Abstract/Free Full Text]
- Coppoolse R, Rees W, Krech R, Hufnagel M, Seufert K, Warnecke H. Routine minimal invasive vein harvesting reduces postoperative morbidity in cardiac bypass procedures. Clinical report of 1400 patients. Eur J Cardiothorac Surg 1999; 16:Suppl_2S61–66.[Abstract/Free Full Text]
- Bonde P, Graham ANJ, Mac Gowan SW. Endoscopic vein harvest: advantages and limitations. Ann Thorac Surg 2004; 77:2076–2082.[Abstract/Free Full Text]
- Jordan WD, Alcocer F, Voellinger DC, Wirthlin DJ. The durability of endoscopic saphenus vein grafts: a 5-year observational study. J Vasc Surg 2001; 34:434–439.[CrossRef][Medline]
- Morris RJ, Butler MT, Samuels LE. Minimally invasive saphenous vein harvesting. Ann Thorac Surg 1998; 66:1026–1028.[Abstract/Free Full Text]
- Allen KB, Griffith GL, Heimansohn DA, Robison RJ, Matheny RG, Schier JJ, Fitzgerald EB, Shaar CJ. Endoscopic versus traditional saphenous vein harvesting: a prospective, randomized trial. Ann Thorac Surg 1998; 66:26–32.[Abstract/Free Full Text]
- Kai M, Hanyu M, Soga Y, Nomoto T, Nakano J, Matsuo T, Umehara E, Kawato M, Okabayashi H. Off-pump coronary artery bypass grafting with skeletonized bilateral internal thoracic arteries in insulin-dependent diabetics. Ann Thorac Surg 2007; 84:32–36.[Abstract/Free Full Text]
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Abstract
1. Introduction
