Minimally invasive saphenous vein harvesting guided by preoperative echotomography: results of a prospective randomized study
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《血管的通路杂志》
Centro Di Ricerca E Formazione Ad Alta Tecnologia, Nelle Scienze Biomediche, Loc. Tappino – Campobasso, Catholic University of the Sacred Heart, Campobasso, Italy
Definitions: Renal insufficiency, postoperative increase of blood creati-nine of 2 mg/dl or more in comparison to preoperative; Peripheral vasculopathy, echo-doppler evidence of atherosclerosis at any district other than the coronary arteries; COPD, cough persisting for at least three months for two consecutive years, plus evidence of obstructive pattern at spirometry; Wound infection, evidence of purulent discharge associated to microbiological identification of causative agent and to pain, heat, swelling, redness with need of surgical re-exploration of the wound; Impaired wound healing, prolonged dehiscence of borders without signs of purulent discharge and with negative microbiological tests; Diabetes, the diagnosis had to be posed by an endocrinologist at least three months before surgery on the basis of blood glucose during fasting (126 mg/dl in two separate measurements) and at oral tolerance test with 75 g of glucose (200 mg/dl two hours after administration); Obesity, BMI>25 at hospital admission.
This work was partially presented at the 54th International Congress of the European Society for Cardiovascular Surgery, Athens, Greece, May 19–22, 2005.
Abstract
Morbidity related to impaired leg wound healing after GSV harvest is a neglected problem with inherent social costs. We developed a minimally invasive harvest (MIH) technique without the need of specific devices guided by preoperative echotomography. We tested it in comparison to open harvest in a prospective, randomized study. One hundred and seven patients were prospectively randomized to receive either MI or conventional (C) harvest. Preoperative Doppler echotomography was performed in order to identify vein segments suitable for CABG and surgically attainable. Multiple skin incisions (up to four per patient and each one up to 5 cm in length) parallel to the vein axis were performed. MI had no adverse effects on graft function and associated to higher graft blood flow after anastomosis, probably due to reduced venospasm. MI was more time-expensive, but resulted in a significantly lower incidence of postoperative wound morbidity. This was particularly evident in patients with risk factors for wound complications. The MI approach is safe and reliable for obtaining venous conduits for CABG. Accurate echotomography mapping of the leg veins is pivotal for its efficacy. Given the low costs and evident benefits, MIH should be tested as an alternative approach in the routine surgical practice.
Key Words: Coronary artery bypass conduits; Saphenous vein; Incisions
1. Introduction
Great saphenous vein (GSV) graft is still widely employed for CABG. The morbidity associated with GSV harvest by longitudinal incision includes haematoma, dehiscence of borders, cellulitis, abscess or wound infections requiring antibiotic therapy and/or debridement, saphenous neuropathy [1,2]. Diabetes, obesity and peripheral vasculopathy are independent predictors of these events [3]. The rate of such complications ranges from 1% to 44% [4]; they contribute to postoperative morbidity along with impaired quality of life and increased in-hospital stay and costs. Several techniques for minimally invasive saphenous vein harvesting (MIH) have become popular in the last few years, with a reported better healing process [5–8]. As a major requirement, MIH methods should not impair graft patency.
Commercially, disposable sets for less invasive MIH still have high costs, and no definitive economical analysis is available clearly stating a cost-minimizing effect of such approaches [5].
The present study was conceived in order to evaluate the effectiveness and safety, in terms of graft functionality, intraoperative timing and impact on postoperative course, of an MIH non-endoscopic procedure developed at our center with the help of preoperative echo-Doppler GSV mapping.
2. Patients and methods
2.1. Patient selection
We prospectively enrolled 107 patients scheduled for isolated elective CABG at our institution from April 2003 to February 2004. This investigation was started after we had reached a good mastery and six-months experience in the MIH technique. All patients met the following inclusion criteria:
Severe coronary artery disease, defined as triple vessel disease with involvement of at least the left anterior descending or the circumflex artery, or as isolated involvement of the left main artery, or as diffuse, tubular stenoses within the coronary vessels and/or ulcerative plaques;
Absence of disease of leg veins including insufficiency, varicosity, and inflammation of any origin, and absence of any vasculitis.
Reoperative CABG was an exclusion criterion.
Informed consent was obtained from all participants. The local Ethical Committee approved the study protocol including the performance of control coronary angiography in all individuals. Patients were randomly assigned to receive either MIH of GSV (MI Group) or saphenectomy by longitudinal incision (C Group).
2.2. Surgical technique
Two different skilled surgeons sutured leg wounds in both groups. Median sternotomy with cardiopulmonary bypass was employed for patients of both groups. Harvested veins were pressure-distended, stored in heparinized blood and used immediately. After weaning from cardio-pulmonary bypass, flow through each graft was quantified by a Doppler probe using a dedicated instrument (Transonic System Inc.), after dropping 2 to 4 ml of a papaverin solution onto grafts.
2.3. Vein harvesting technique
The donor leg is abducted and GSV segments are harvested by two to four minimal skin incisions (up to 5 cm in length for each one) in the MI group. Neither retractor systems nor robot supports are needed. The first incision is performed parallel to the vein axis at 3 to 6 cm above the ankle if preoperative echotomography mapping has revealed optimal vein caliber at this level; conversely, the skin is initially incised in coincidence of the vein segment identified as the most suitable at ultrasonographic mapping. The skin is lifted by a single silk stitch and the vein is exposed, tissue adherences are gently removed and the side branches are ligated. A second incision is performed 10 to 12 cm proximally to the first; the corresponding segment is isolated and the distal part of the vein is passed beneath the skin bridge. Side branches in the tunnels are directly visualized and ligated by metal clips. Traditional longitudinal incision from the ankle up to the medial thigh was performed in the C group of patients. Harvesting times and length of vein suitable for grafting were recorded for both groups. All leg incisions were closed by an absorbable 3-0 suture after reversion of anticoagulation by protamine and local hemostasis. A running skin suture was used for closure of all conventional harvest wounds, while in 48% of the MI group of individuals we adopted interrupted Donati stitches.
2.4. Cost analysis
As at our institution, endoscopic vein harvest was shortly adopted before the start of the present protocol, financial records were retrospectively reviewed with the aim of determining the additional cost related to endoscopic armamentarium in comparison to patients operated on by open harvest. The overall cost for each patient was calculated taking into account: disposable materials, diagnostic tests, drugs, laboratory tests and blood components using financial records. Charges related to preoperative echotomography mapping were included for the MI group of patients. Hospital fixed costs and surgical team costs were excluded as they are not easily compared between different institutions. The difference in cost between the MI and the C Group patients was determined.
2.5. Follow-up
Occurrence of any complication of leg wound healing was monitored during the first 10 postoperative days. The diagnosis of infection or dehiscence was posed by an independent general surgeon in agreement with the cardiac surgeon. A second unaware general surgeon was consulted in the event of disagreement. Pain referred to leg incision was quantified by an analogical pain scale ranging from 0 (no pain) to 10 (worst pain imaginable) [13] at the 1st, 2nd, 5th and 10th postoperative days. Patients were followed-up by routine outpatient examination and echocardiography at 1, 2 and 3 months postoperatively and later by telephone interviews. Graft angiography was performed in all patients 2±0.4 months after surgery; the interpretation was performed by two independent skilled cardiologists in a blinded way.
2.6. Statistical analysis
All data were prospectively included in an electronic database (SPSS, Chicago, IL). Continuous data are presented as mean±standard deviation. Groups comparison was performed by two-tailed t testing and by chi-square testing for continuous and nominal data, respectively. Risk factor analysis for any leg wound complications (categorical re-sponse variable) was performed by univariate analysis, and variables were then included in the multiple logistic regression model, if appropriate. The assumptions of multiple logistic regression were checked by informal testing and were met by all presented variables; the model was validated through a common ‘jack-knife’ procedure. The goodness-of-fit of the final model was assessed by the likelihood ratio criterion. Statistical significance was set at the 0.05 level. Details of statistical power calculations for two-sided unpaired t testing: =4, =20, =0.05, 1–=0.9.
3. Results
Preoperative features of study population are presented in Table 1. Surgical results and early postoperative outcome data are summarized in Table 2. No differences among the groups emerged in terms of grafted arteries, number of grafts per patient and CPB time. Harvesting required a shorter time adopting the C technique, although the difference reached no significance (observed difference 9.1±3.5 min). Similar results were obtained by the comparison of length-to-time ratio among the two groups. The MI approach was associated to a markedly reduced length of incision (P<0.001) and shorter time for suturing (P=0.016), but did not lead to undersized available graft. Blood flow through implanted vein was ameliorated in segments obtained by the MI technique (P=0.042). No major differences could be observed in the rates of major complications and mean length of intensive care unit (ICU) stay time. While 18 episodes of any leg wound complications occurred in 16 patients of the C group, only one case of wound haematoma and one case of borders dehiscence were observed in the MI group (OR, 0.09, 95% CI 0.01–0.44, P<0.001). The MI technique was protective against development of wound inflammation/infection (requiring drug administration, P=0.04) and dehiscence of borders (P=0.031). Symptoms and signs of infections became evident from day 5 to day 9, and the diagnosis was confirmed by isolation of etiologic agents, which were Pseudomonas Aeruginosa in two cases, Pseudomonas species in one case and Staphylococcus Aureus in one case. Rates of haematoma (observed difference 3 episodes, OR 0.23, 95% CI 0.01–2.32, P=0.20) and of need for surgical revision (observed difference: 2 episodes, OR 0.00, 95% CI 0.00–4.03, P=0.24) were depressed in the MI group, although without reaching statistical significance. Results of pain analysis are presented in Fig. 1. All patients individually reported the pain score. None of them quantified pain as 9 or 10. Mean scores of the two groups decreased regularly over time, but the C group members reported higher pain in comparison to the MI patients at all time intervals.
The profile of a patient at higher risk of leg wound complications includes diabetes, peripheral vasculopathy, renal failure, and cumulative length of leg skin incision (Table 3). Obesity was not associated to the response variable (OR 0.83). The MI approach was not associated with increased risk of wound morbidity neither at the univariate nor at the multivariate analysis.
At the end of the short-term follow-up, we had no cases of angina reoccurrence in any group.
From a review of records at our institution, the mean additional hospital charge for endoscopic vein harvest was 1605 per patient. In comparison to the C Group individuals, for each patient operated on by the MI approach we saved 703, despite an additional charge of 80 for preoperative leg vein mapping.
4. Comment
Leg wound-related morbidity after GSV harvest significantly contributes to the postoperative course of the patients. Even ten days postoperatively and after hospital discharge, pain during wound healing might worsen the quality of life of patients who suffered no major complications, with the impact on ambulation, discomfort and additional treatment costs. Such effects are often underestimated by surgeons.
Most MI techniques reported in the literature are associated to good vein quality and patency, but often need dedicated instruments. Here we present the impact on in-hospital outcome of an MI technique performable without any additive armamentarium. Doppler ultrasonography is employed for identification of vein segments with optimal caliber and surgically attainable. This MI approach proved to be comparable to conventional techniques in terms of early graft failure rate, total length of available vein and intraoperative flow. Surgical time requested for harvesting was increased by MI, as a consequence of problems in reaching under the lifted skin side branches to be clipped.
Among venous grafts harvested by MI, we observed higher blood flow in comparison to veins obtained by the C approach, reaching significance (P=0.041). Prior to comparison of flow data, we weighed against mean blood pressure values at the time of intraoperative Doppler probe and found no difference among groups (data not shown). Further studies taking into account the biochemical response to our MI approach should be undertaken to clarify this issue. Early patency rate at control coronary angiography was comparable between veins obtained by the MI and the traditional method. This confirms the experience of other investigators. Although we cannot definitively quantify the impact of our MI technique in reducing venospasm and even rate of graft restenosis, our data reliably suggest that the presented MI approach does not alter vessel quality. Longer surgical times observed in our cohort are outweighed by actual benefits for the patients. Reported endoscopic harvest methods lessen social costs by reducing leg wound-related complications [14], although some authors depicted them as ‘cost-neutral’, due to charges for disposable armamentarium [15]. We report a mean 703 saving per patient operated on by the MI technique. Reduction of hospital charges is much more evident as no endoscopic equipment is required, which accounts in our retrospective experience for a 1605 additional charge. Furthermore, we performed Doppler ultrasonography mapping in both the C and MI group individuals, which improves the reliability of results comparison.
In contrast to published literature, obesity was not a predictor of wound complications in our series, probably due to insufficient sample size and selection bias. The benefits related to the MI approach are conversely emphasized in patients with vasculopathy, diabetes, and renal insufficiency.
We conclude that the described MI technique has no adverse effects and is reliable for obtaining venous conduits for CABG. The absence of any adverse episode in the MI group is a clinically important event. The prospective randomized nature of this study and restrictive inclusion criteria counterbalance the limitations related to small sample size, single-centre experience and non-blinded design. MI is associated to better leg wound healing, reduced pain and minor postoperative morbidity in comparison to open harvest. MI should be considered as an alternative approach for vein harvest for CABG.
Acknowledgments
The authors are grateful to Dr Carlo Canosa, Dr Carlo De Filippo, Dr Paola Spatuzza and Dr Mario Gaudino for their contributions in the realization of this manuscript.
References
Wipke-Tevis DD, Stotts NA, Skov P, Carrieri-Kohlman V. Frequency, manifestations, and correlates of impaired healing of saphenous vein harvest incisions. Heart Lung 1996;25:108–116.
Utley JR, Thomason ME, Wallace DJ, Mutch DW, Staton L, Brown V, Wilde CM, Bell MS. Preoperative correlates of impaired wound healing after saphenous vein excision. J Thorac Cardiovasc Surg 1989;98:147–149.
Allen KB, Heimansohn DA, Robison RJ, Schier JJ, Griffith GL, Fitzgerald EB, Isch JH, Abraham S, Shaar CJ. Risk factors for leg wound complications following endoscopic vs. traditional saphenous vein harvesting. Heart Surg Forum 2000;3:325–330.
Felisky CD, Paull DL, Hill ME, Hall RA, Ditkoff M, Campbell WG, Guyton SW. Endoscopic greater saphenous vein harvesting reduces the morbidity of coronary artery bypass surgery. Am J Surg 2002;183:576–579.
Cisowski M, Wites M, Gerber W, Drzewiecka-Gerber A, Bochenek A. Minimally invasive saphenous harvesting for coronary artery bypass grafting – comparison of three less invasive methods. Med Sci Monit 2000;6:735–739.
Risnes I, Abdelnoor M, Lundblad R, Baksaas ST, Svennevig JL. Leg wound closure after saphenous vein harvesting in patients undergoing coronary artery bypass grafting: a prospective randomized study comparing intracutaneous, transcutaneous and zipper techniques. Scand Cardiovasc J 2002;36:378–382.
Schurr UP, Lachat ML, Reuthebuch O, Kadner A, Mader M, Seiffert B, Hoerstrup SP, Zund G, Genoni M, Turina MI. Endoscopic saphenous vein harvesting for CABG – a randomized, prospective trial. Thorac Cardiovasc Surg 2002;50:160–163.
Crouch JD, O'Hair DP, Keuler JP, Barragry TP, Werner PH, Kleinman LH. Open vs. endoscopic saphenous vein harvesting: wound complications and vein quality. Ann Thorac Surg 1999;68:1513–1516.
Souza D, Dashwood MR, Tsui J, Filbey D, Bodin L, Johansson B, Borowiec J. Improved patency in vein grafts harvested with surrounding tissue: results of a randomized study using three harvesting techniques. Ann Thorac Surg 2002;73:1189–1195.
Black E, Guzik TJ, West N, Campbell K, Pillai R, Ratnatunga C, Channon KM. Minimally invasive saphenous vein harvesting: effects on endothelial and smooth muscle function. Ann Thorac Surg 2001;71:1503–1507.
Alrawi SJ, Balaya F, Raju R, Cunningham JN Jr, Acinapura AJ. A comparative study of endothelial cell injury during open and endoscopic saphenectomy: an electron microscopic evaluation. Heart Surg Forum 2001;4:120–127.
Tsui JC, Souza DS, Filbey D, Bomfim V, Dashwood MR. Preserved endothelial integrity and nitric oxide synthase in saphenous vein grafts harvested by a ‘no-touch’ technique. Br J Surg 2001;88:1209–1215.
Acute Pain Management Guideline Panel. Acute pain management: operative or medical procedures and trauma. Clinical practice guideline February 1992;Rockville MD: Agency of Health Care Policy and Research, Public Health Service, US Dept of Health and Human Services AHCPR publication 92–0032.
Illig KA, Rhodes JM, Sternbach I, Green RM. Financial impact of endoscopic vein harvest for infrainguinal bypass. J Vasc Surg 2003;37:323–330.
Puskas JD, Wright CE, Miller PK, Anderson TE, Gott JP, Brown 3rd WM, Guyton RA. A randomized trial of endoscopic versus open saphenous vein harvest in coronary bypass surgery. Ann Thorac Surg 1999;68:1509–1512.(Giuseppe Nasso, Amedeo An)
Definitions: Renal insufficiency, postoperative increase of blood creati-nine of 2 mg/dl or more in comparison to preoperative; Peripheral vasculopathy, echo-doppler evidence of atherosclerosis at any district other than the coronary arteries; COPD, cough persisting for at least three months for two consecutive years, plus evidence of obstructive pattern at spirometry; Wound infection, evidence of purulent discharge associated to microbiological identification of causative agent and to pain, heat, swelling, redness with need of surgical re-exploration of the wound; Impaired wound healing, prolonged dehiscence of borders without signs of purulent discharge and with negative microbiological tests; Diabetes, the diagnosis had to be posed by an endocrinologist at least three months before surgery on the basis of blood glucose during fasting (126 mg/dl in two separate measurements) and at oral tolerance test with 75 g of glucose (200 mg/dl two hours after administration); Obesity, BMI>25 at hospital admission.
This work was partially presented at the 54th International Congress of the European Society for Cardiovascular Surgery, Athens, Greece, May 19–22, 2005.
Abstract
Morbidity related to impaired leg wound healing after GSV harvest is a neglected problem with inherent social costs. We developed a minimally invasive harvest (MIH) technique without the need of specific devices guided by preoperative echotomography. We tested it in comparison to open harvest in a prospective, randomized study. One hundred and seven patients were prospectively randomized to receive either MI or conventional (C) harvest. Preoperative Doppler echotomography was performed in order to identify vein segments suitable for CABG and surgically attainable. Multiple skin incisions (up to four per patient and each one up to 5 cm in length) parallel to the vein axis were performed. MI had no adverse effects on graft function and associated to higher graft blood flow after anastomosis, probably due to reduced venospasm. MI was more time-expensive, but resulted in a significantly lower incidence of postoperative wound morbidity. This was particularly evident in patients with risk factors for wound complications. The MI approach is safe and reliable for obtaining venous conduits for CABG. Accurate echotomography mapping of the leg veins is pivotal for its efficacy. Given the low costs and evident benefits, MIH should be tested as an alternative approach in the routine surgical practice.
Key Words: Coronary artery bypass conduits; Saphenous vein; Incisions
1. Introduction
Great saphenous vein (GSV) graft is still widely employed for CABG. The morbidity associated with GSV harvest by longitudinal incision includes haematoma, dehiscence of borders, cellulitis, abscess or wound infections requiring antibiotic therapy and/or debridement, saphenous neuropathy [1,2]. Diabetes, obesity and peripheral vasculopathy are independent predictors of these events [3]. The rate of such complications ranges from 1% to 44% [4]; they contribute to postoperative morbidity along with impaired quality of life and increased in-hospital stay and costs. Several techniques for minimally invasive saphenous vein harvesting (MIH) have become popular in the last few years, with a reported better healing process [5–8]. As a major requirement, MIH methods should not impair graft patency.
Commercially, disposable sets for less invasive MIH still have high costs, and no definitive economical analysis is available clearly stating a cost-minimizing effect of such approaches [5].
The present study was conceived in order to evaluate the effectiveness and safety, in terms of graft functionality, intraoperative timing and impact on postoperative course, of an MIH non-endoscopic procedure developed at our center with the help of preoperative echo-Doppler GSV mapping.
2. Patients and methods
2.1. Patient selection
We prospectively enrolled 107 patients scheduled for isolated elective CABG at our institution from April 2003 to February 2004. This investigation was started after we had reached a good mastery and six-months experience in the MIH technique. All patients met the following inclusion criteria:
Severe coronary artery disease, defined as triple vessel disease with involvement of at least the left anterior descending or the circumflex artery, or as isolated involvement of the left main artery, or as diffuse, tubular stenoses within the coronary vessels and/or ulcerative plaques;
Absence of disease of leg veins including insufficiency, varicosity, and inflammation of any origin, and absence of any vasculitis.
Reoperative CABG was an exclusion criterion.
Informed consent was obtained from all participants. The local Ethical Committee approved the study protocol including the performance of control coronary angiography in all individuals. Patients were randomly assigned to receive either MIH of GSV (MI Group) or saphenectomy by longitudinal incision (C Group).
2.2. Surgical technique
Two different skilled surgeons sutured leg wounds in both groups. Median sternotomy with cardiopulmonary bypass was employed for patients of both groups. Harvested veins were pressure-distended, stored in heparinized blood and used immediately. After weaning from cardio-pulmonary bypass, flow through each graft was quantified by a Doppler probe using a dedicated instrument (Transonic System Inc.), after dropping 2 to 4 ml of a papaverin solution onto grafts.
2.3. Vein harvesting technique
The donor leg is abducted and GSV segments are harvested by two to four minimal skin incisions (up to 5 cm in length for each one) in the MI group. Neither retractor systems nor robot supports are needed. The first incision is performed parallel to the vein axis at 3 to 6 cm above the ankle if preoperative echotomography mapping has revealed optimal vein caliber at this level; conversely, the skin is initially incised in coincidence of the vein segment identified as the most suitable at ultrasonographic mapping. The skin is lifted by a single silk stitch and the vein is exposed, tissue adherences are gently removed and the side branches are ligated. A second incision is performed 10 to 12 cm proximally to the first; the corresponding segment is isolated and the distal part of the vein is passed beneath the skin bridge. Side branches in the tunnels are directly visualized and ligated by metal clips. Traditional longitudinal incision from the ankle up to the medial thigh was performed in the C group of patients. Harvesting times and length of vein suitable for grafting were recorded for both groups. All leg incisions were closed by an absorbable 3-0 suture after reversion of anticoagulation by protamine and local hemostasis. A running skin suture was used for closure of all conventional harvest wounds, while in 48% of the MI group of individuals we adopted interrupted Donati stitches.
2.4. Cost analysis
As at our institution, endoscopic vein harvest was shortly adopted before the start of the present protocol, financial records were retrospectively reviewed with the aim of determining the additional cost related to endoscopic armamentarium in comparison to patients operated on by open harvest. The overall cost for each patient was calculated taking into account: disposable materials, diagnostic tests, drugs, laboratory tests and blood components using financial records. Charges related to preoperative echotomography mapping were included for the MI group of patients. Hospital fixed costs and surgical team costs were excluded as they are not easily compared between different institutions. The difference in cost between the MI and the C Group patients was determined.
2.5. Follow-up
Occurrence of any complication of leg wound healing was monitored during the first 10 postoperative days. The diagnosis of infection or dehiscence was posed by an independent general surgeon in agreement with the cardiac surgeon. A second unaware general surgeon was consulted in the event of disagreement. Pain referred to leg incision was quantified by an analogical pain scale ranging from 0 (no pain) to 10 (worst pain imaginable) [13] at the 1st, 2nd, 5th and 10th postoperative days. Patients were followed-up by routine outpatient examination and echocardiography at 1, 2 and 3 months postoperatively and later by telephone interviews. Graft angiography was performed in all patients 2±0.4 months after surgery; the interpretation was performed by two independent skilled cardiologists in a blinded way.
2.6. Statistical analysis
All data were prospectively included in an electronic database (SPSS, Chicago, IL). Continuous data are presented as mean±standard deviation. Groups comparison was performed by two-tailed t testing and by chi-square testing for continuous and nominal data, respectively. Risk factor analysis for any leg wound complications (categorical re-sponse variable) was performed by univariate analysis, and variables were then included in the multiple logistic regression model, if appropriate. The assumptions of multiple logistic regression were checked by informal testing and were met by all presented variables; the model was validated through a common ‘jack-knife’ procedure. The goodness-of-fit of the final model was assessed by the likelihood ratio criterion. Statistical significance was set at the 0.05 level. Details of statistical power calculations for two-sided unpaired t testing: =4, =20, =0.05, 1–=0.9.
3. Results
Preoperative features of study population are presented in Table 1. Surgical results and early postoperative outcome data are summarized in Table 2. No differences among the groups emerged in terms of grafted arteries, number of grafts per patient and CPB time. Harvesting required a shorter time adopting the C technique, although the difference reached no significance (observed difference 9.1±3.5 min). Similar results were obtained by the comparison of length-to-time ratio among the two groups. The MI approach was associated to a markedly reduced length of incision (P<0.001) and shorter time for suturing (P=0.016), but did not lead to undersized available graft. Blood flow through implanted vein was ameliorated in segments obtained by the MI technique (P=0.042). No major differences could be observed in the rates of major complications and mean length of intensive care unit (ICU) stay time. While 18 episodes of any leg wound complications occurred in 16 patients of the C group, only one case of wound haematoma and one case of borders dehiscence were observed in the MI group (OR, 0.09, 95% CI 0.01–0.44, P<0.001). The MI technique was protective against development of wound inflammation/infection (requiring drug administration, P=0.04) and dehiscence of borders (P=0.031). Symptoms and signs of infections became evident from day 5 to day 9, and the diagnosis was confirmed by isolation of etiologic agents, which were Pseudomonas Aeruginosa in two cases, Pseudomonas species in one case and Staphylococcus Aureus in one case. Rates of haematoma (observed difference 3 episodes, OR 0.23, 95% CI 0.01–2.32, P=0.20) and of need for surgical revision (observed difference: 2 episodes, OR 0.00, 95% CI 0.00–4.03, P=0.24) were depressed in the MI group, although without reaching statistical significance. Results of pain analysis are presented in Fig. 1. All patients individually reported the pain score. None of them quantified pain as 9 or 10. Mean scores of the two groups decreased regularly over time, but the C group members reported higher pain in comparison to the MI patients at all time intervals.
The profile of a patient at higher risk of leg wound complications includes diabetes, peripheral vasculopathy, renal failure, and cumulative length of leg skin incision (Table 3). Obesity was not associated to the response variable (OR 0.83). The MI approach was not associated with increased risk of wound morbidity neither at the univariate nor at the multivariate analysis.
At the end of the short-term follow-up, we had no cases of angina reoccurrence in any group.
From a review of records at our institution, the mean additional hospital charge for endoscopic vein harvest was 1605 per patient. In comparison to the C Group individuals, for each patient operated on by the MI approach we saved 703, despite an additional charge of 80 for preoperative leg vein mapping.
4. Comment
Leg wound-related morbidity after GSV harvest significantly contributes to the postoperative course of the patients. Even ten days postoperatively and after hospital discharge, pain during wound healing might worsen the quality of life of patients who suffered no major complications, with the impact on ambulation, discomfort and additional treatment costs. Such effects are often underestimated by surgeons.
Most MI techniques reported in the literature are associated to good vein quality and patency, but often need dedicated instruments. Here we present the impact on in-hospital outcome of an MI technique performable without any additive armamentarium. Doppler ultrasonography is employed for identification of vein segments with optimal caliber and surgically attainable. This MI approach proved to be comparable to conventional techniques in terms of early graft failure rate, total length of available vein and intraoperative flow. Surgical time requested for harvesting was increased by MI, as a consequence of problems in reaching under the lifted skin side branches to be clipped.
Among venous grafts harvested by MI, we observed higher blood flow in comparison to veins obtained by the C approach, reaching significance (P=0.041). Prior to comparison of flow data, we weighed against mean blood pressure values at the time of intraoperative Doppler probe and found no difference among groups (data not shown). Further studies taking into account the biochemical response to our MI approach should be undertaken to clarify this issue. Early patency rate at control coronary angiography was comparable between veins obtained by the MI and the traditional method. This confirms the experience of other investigators. Although we cannot definitively quantify the impact of our MI technique in reducing venospasm and even rate of graft restenosis, our data reliably suggest that the presented MI approach does not alter vessel quality. Longer surgical times observed in our cohort are outweighed by actual benefits for the patients. Reported endoscopic harvest methods lessen social costs by reducing leg wound-related complications [14], although some authors depicted them as ‘cost-neutral’, due to charges for disposable armamentarium [15]. We report a mean 703 saving per patient operated on by the MI technique. Reduction of hospital charges is much more evident as no endoscopic equipment is required, which accounts in our retrospective experience for a 1605 additional charge. Furthermore, we performed Doppler ultrasonography mapping in both the C and MI group individuals, which improves the reliability of results comparison.
In contrast to published literature, obesity was not a predictor of wound complications in our series, probably due to insufficient sample size and selection bias. The benefits related to the MI approach are conversely emphasized in patients with vasculopathy, diabetes, and renal insufficiency.
We conclude that the described MI technique has no adverse effects and is reliable for obtaining venous conduits for CABG. The absence of any adverse episode in the MI group is a clinically important event. The prospective randomized nature of this study and restrictive inclusion criteria counterbalance the limitations related to small sample size, single-centre experience and non-blinded design. MI is associated to better leg wound healing, reduced pain and minor postoperative morbidity in comparison to open harvest. MI should be considered as an alternative approach for vein harvest for CABG.
Acknowledgments
The authors are grateful to Dr Carlo Canosa, Dr Carlo De Filippo, Dr Paola Spatuzza and Dr Mario Gaudino for their contributions in the realization of this manuscript.
References
Wipke-Tevis DD, Stotts NA, Skov P, Carrieri-Kohlman V. Frequency, manifestations, and correlates of impaired healing of saphenous vein harvest incisions. Heart Lung 1996;25:108–116.
Utley JR, Thomason ME, Wallace DJ, Mutch DW, Staton L, Brown V, Wilde CM, Bell MS. Preoperative correlates of impaired wound healing after saphenous vein excision. J Thorac Cardiovasc Surg 1989;98:147–149.
Allen KB, Heimansohn DA, Robison RJ, Schier JJ, Griffith GL, Fitzgerald EB, Isch JH, Abraham S, Shaar CJ. Risk factors for leg wound complications following endoscopic vs. traditional saphenous vein harvesting. Heart Surg Forum 2000;3:325–330.
Felisky CD, Paull DL, Hill ME, Hall RA, Ditkoff M, Campbell WG, Guyton SW. Endoscopic greater saphenous vein harvesting reduces the morbidity of coronary artery bypass surgery. Am J Surg 2002;183:576–579.
Cisowski M, Wites M, Gerber W, Drzewiecka-Gerber A, Bochenek A. Minimally invasive saphenous harvesting for coronary artery bypass grafting – comparison of three less invasive methods. Med Sci Monit 2000;6:735–739.
Risnes I, Abdelnoor M, Lundblad R, Baksaas ST, Svennevig JL. Leg wound closure after saphenous vein harvesting in patients undergoing coronary artery bypass grafting: a prospective randomized study comparing intracutaneous, transcutaneous and zipper techniques. Scand Cardiovasc J 2002;36:378–382.
Schurr UP, Lachat ML, Reuthebuch O, Kadner A, Mader M, Seiffert B, Hoerstrup SP, Zund G, Genoni M, Turina MI. Endoscopic saphenous vein harvesting for CABG – a randomized, prospective trial. Thorac Cardiovasc Surg 2002;50:160–163.
Crouch JD, O'Hair DP, Keuler JP, Barragry TP, Werner PH, Kleinman LH. Open vs. endoscopic saphenous vein harvesting: wound complications and vein quality. Ann Thorac Surg 1999;68:1513–1516.
Souza D, Dashwood MR, Tsui J, Filbey D, Bodin L, Johansson B, Borowiec J. Improved patency in vein grafts harvested with surrounding tissue: results of a randomized study using three harvesting techniques. Ann Thorac Surg 2002;73:1189–1195.
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