© 2013 Wiley Periodicals, Inc.
47
ORIGINAL ARTICLE _____________________________________________________________
Skeletonization Technique in Coronary Artery Bypass Graft Surgery Reduces the Postoperative Pain Intensity and Disability Index Faizan Imran Bawany, M.B.B.S.,* Muhammad Shahzeb Khan, M.B.B.S.,* Asadullah Khan, M.B.B.S., F.C.P.S.,y and Mehwish Hussain, M.Sc., Ph.D.* *Dow University of Health Sciences (DUHS), Karachi, Pakistan; and yCardiac Surgery Department, Civil Hospital, DUHS, Karachi, Pakistan ABSTRACT Background and Aim: Benefits of the skeletonized internal thoracic artery (ITA) include increased graft flow, increased graft length, and reduced incidence of sternal complications. We conducted a randomized, double-blinded comparison of skeletonized versus pedicled ITA to assess the differences in pain intensity and extent of disability between the two types of harvesting procedures at one and three months follow-up. Methods: A total of 50 patients were included in our study. Twenty-five patients had undergone skeletonized grafting while the other half had undergone pedicled grafting. The patients were evaluated for their pain at one and three months postoperatively. Extent of disability was measured via Pain Disability Index and intensity of pain was measured via Visual Analogue Scale (VAS). The patients were also questioned about the details of their pain using Short Form McGill Pain Questionnaire. Results: In the first month, the mean pain intensity measured through VAS was 30.4 W 4.0 and 55.0 W 5.7 mm in skeletonized and pedicle group, respectively. The pedicled group had significantly higher scores measured by all three scales at both one- and three-month intervals (p-values < 0.0001). Conclusions: Our results indicate that skeletonization of ITA significantly reduces postcoronary artery bypass graft surgery pain at both one- and three-month intervals. Long-term clinical trials involving larger sample sizes should be conducted to fully confirm the benefits of the skeletonization technique. doi: 10.1111/jocs.12273 (J Card Surg 2014;29:47–50) Nonanginal chest wall pain is a frequent complication of coronary artery bypass graft (CABG) surgery. The prevalence of post-CABG pain lies between 30% and 60%.1 The mechanism for this post-CABG pain remains undefined. However, it is largely believed that the pain is neurogenic in nature and is a result of damage to the chest wall during internal thoracic artery (ITA) harvesting.2 ITA can be dissected in two manners, pedicled or skeletonized. The skeletonization technique helps to maintain the sternal blood flow and to preserve the integrity of chest wall. As a result, it helps to reduce postoperative sternal complications.3–5 Furthermore, some studies have also suggested that skeletonization reduces post-CABG pain.6
Conflict of interest: The authors acknowledge no conflict of interest in the submission. Address for correspondence: Muhammad Shahzeb Khan, M.B.B.S., Dow University of Health Sciences (DUHS), 109/2, Main Kha-e-Bane Amirkhusro, Phase 6, DHA, Karachi, Pakistan. Fax: 0092215843157; e-mail: [email protected]
The incidence and character of post-CABG pain among skeletonized and pedicled ITA-grafted patients is not well known. This study was done to investigate whether skeletonized or pedicle harvesting results in lesser incidence and intensity of post-CABG pain.
MATERIALS AND METHODS This study was approved by the Institutional Review Board of Dow University of Health Sciences. We interviewed by phone a total of 116 patients who had undergone primary isolated CABG surgery from May 2012 to June 2013. The calls were made two days before the end of the patients’ one-month postoperative interval to inquire about the presence of postoperative pain. Out of 116 patients undergoing surgery during this time period, 46 had been operated by pedicled grafting while the remaining 70 had undergone skeletonized grafting. Out of the 46 pedicled-grafted patients, 29 stated on the phone that they had pain but only 27 reported at our hospital to participate in our study
48
BAWANY, ET AL. SKELETONIZATION REDUCES PAIN INTENSITY
for their pain evaluation. Two patients were excluded from the study as their pain was due to angina. Out of the 70 patients in the skeletonized group, 26 experienced pain and all of them reported for their pain evaluation. One patient chosen randomly from the skeletonized group was excluded from the study to have an equal number of participants from both the groups to enable fair comparisons. All the 50 patients gave written consent to take part in the study. Two interviewers were assigned the task of doing the pain evaluation from the patients at the one-month interval. The patients who were included in our study were unaware whether they had received skeletonized or pedicled grafts. The interviewers were also not aware whether they were interviewing skeletonized- or pedicled-grafted patients. The same 50 patients were also evaluated for their pain three months postoperatively by the same interviewers. The patients were questioned about the details of their pain using the Short Form McGill Pain Questionnaire (SFMPQ).7 The extent of disability was measured through the Pain Disability Index8 (PDI) and intensity of pain was measured through the 10-cm Visual Analogue Scale (VAS).9 The exact location of the pain was localized to one of the following: right anterior chest, left anterior chest, or midline. A number of aggravating factors were also inquired from the patients. Aggravating factors were scored out of a maximum of six points and included the following: walking, upper limb movement, deep breathing, touch, stress, and pressure put on the painful site.
J CARD SURG 2014;29:47–50
RESULTS Thirty-one patients were males (62%) and 19 (38%) were females. In the first month, the mean pain intensity measured through VAS was 30.4 4.0 and 55.0 5.7 mm in skeletonized and pedicled groups, respectively. The PDI score was 34.1 2.7 and 47.2 5.3 in skeletonized and pedicled groups, respectively. The mean scores calculated from SFMPQ were 9.3 1.0 and 13.8 2.0 in skeletonized and pedicled groups, respectively. The pedicled group had significantly higher scores measured by all three scales as compared with the skeletonized group (p-values < 0.0001) (Table 1). The scores for the three scales were again calculated in the third month for the same patients. Compared to the first month, the pain scores obtained were significantly less in the third month (Figs. 1–3). This significant reduction was observed in both groups as measured by repeated measure ANOVA (p-values < 0.0001). However, the pain scores from pedicled group were still higher than the skeletonized group (Table 2). Most of the pain felt by the patients was in left anterior chest wall (n ¼ 41, 82%). The majority of the patients observed mild pain (n ¼ 26, 52%). Some patients who underwent pedicled harvesting felt distressing (n ¼ 9) and few experienced horrible pain (n ¼ 3) while no patients in the skeletonized group suffered such type of pain. The number of aggravating factors was also significantly higher in the pedicled group (p ¼ 0.002) (Table 3).
THE FOLLOWING TECHNIQUES WERE USED IN SKELETONIZED AND NON-SKELETONIZED ITA HARVESTING After median sternotomy and removal of the thymic remnant, the ITA retractor was applied and the pleura was opened. In the nonskeletonized ITA, the dissection was started from down upwards and included division of the satellite veins and muscle using fine tip curved forceps and unipolar bovie electrocautery. In the skeletonized ITA, the dissection was started from upwards with ring tip fine forceps, fine tip scissors, and unipolar electrocautery at low levels. Papaverine injection was sprayed on ITA in both groups. None of the patients received narcotic pain medication upon discharge and none were taking narcotics at the time the questionnaires were performed. STATISTICAL ANALYSIS Data are presented as the mean and standard deviation for continuous variables and frequency with percentages for categorical variables. Chi-squared test was used to assess categorical variables. MannWhitney U-test was run to compare the pain scores and aggravating factors between skeletonized and pedicled groups. Repeated measure ANOVA was performed to observe change of pain scores at the first and third months in both groups. p-Values less than 0.05 were considered to be significant. All analyses were performed in IBM SPSS v. 21.0.
DISCUSSION The benefits of skeletonized harvesting include increased graft flow,10 increased graft length,11,12 and decreased incidence of mediastinitis.12 Another important benefit of skeletonized harvesting is the reduction in postoperative pain.6 Pain is a subjective sensation and has a major impact on the quality of life of patients. Studies have shown that persistent pain and dysesthesia lead to a significant reduction in quality of life.13 The results of our study indicate that post-CABG pain can have a serious effect on health-related quality of life as measured by the PDI score. Studies have shown that certain properties of ITA and the way in which it is harvested have a major impact on postoperative morbidity and pain.14 Our study indicates that the pedicled group had a significantly greater VAS, PDI, and SFMPQ score at one and three months follow-up.
TABLE 1 Scores Obtained by Visual Analogue Scale (VAS), Pain Disability Index (PDI), and McGill Pain Scale at First Month
VAS PDI McGill Pain Scale
Skeletonized
Pedicle
P-Value
30.4 4.0 34.1 2.7 9.3 1.0
55.0 5.7 47.2 5.3 13.8 2.0
47
ORIGINAL ARTICLE _____________________________________________________________
Skeletonization Technique in Coronary Artery Bypass Graft Surgery Reduces the Postoperative Pain Intensity and Disability Index Faizan Imran Bawany, M.B.B.S.,* Muhammad Shahzeb Khan, M.B.B.S.,* Asadullah Khan, M.B.B.S., F.C.P.S.,y and Mehwish Hussain, M.Sc., Ph.D.* *Dow University of Health Sciences (DUHS), Karachi, Pakistan; and yCardiac Surgery Department, Civil Hospital, DUHS, Karachi, Pakistan ABSTRACT Background and Aim: Benefits of the skeletonized internal thoracic artery (ITA) include increased graft flow, increased graft length, and reduced incidence of sternal complications. We conducted a randomized, double-blinded comparison of skeletonized versus pedicled ITA to assess the differences in pain intensity and extent of disability between the two types of harvesting procedures at one and three months follow-up. Methods: A total of 50 patients were included in our study. Twenty-five patients had undergone skeletonized grafting while the other half had undergone pedicled grafting. The patients were evaluated for their pain at one and three months postoperatively. Extent of disability was measured via Pain Disability Index and intensity of pain was measured via Visual Analogue Scale (VAS). The patients were also questioned about the details of their pain using Short Form McGill Pain Questionnaire. Results: In the first month, the mean pain intensity measured through VAS was 30.4 W 4.0 and 55.0 W 5.7 mm in skeletonized and pedicle group, respectively. The pedicled group had significantly higher scores measured by all three scales at both one- and three-month intervals (p-values < 0.0001). Conclusions: Our results indicate that skeletonization of ITA significantly reduces postcoronary artery bypass graft surgery pain at both one- and three-month intervals. Long-term clinical trials involving larger sample sizes should be conducted to fully confirm the benefits of the skeletonization technique. doi: 10.1111/jocs.12273 (J Card Surg 2014;29:47–50) Nonanginal chest wall pain is a frequent complication of coronary artery bypass graft (CABG) surgery. The prevalence of post-CABG pain lies between 30% and 60%.1 The mechanism for this post-CABG pain remains undefined. However, it is largely believed that the pain is neurogenic in nature and is a result of damage to the chest wall during internal thoracic artery (ITA) harvesting.2 ITA can be dissected in two manners, pedicled or skeletonized. The skeletonization technique helps to maintain the sternal blood flow and to preserve the integrity of chest wall. As a result, it helps to reduce postoperative sternal complications.3–5 Furthermore, some studies have also suggested that skeletonization reduces post-CABG pain.6
Conflict of interest: The authors acknowledge no conflict of interest in the submission. Address for correspondence: Muhammad Shahzeb Khan, M.B.B.S., Dow University of Health Sciences (DUHS), 109/2, Main Kha-e-Bane Amirkhusro, Phase 6, DHA, Karachi, Pakistan. Fax: 0092215843157; e-mail: [email protected]
The incidence and character of post-CABG pain among skeletonized and pedicled ITA-grafted patients is not well known. This study was done to investigate whether skeletonized or pedicle harvesting results in lesser incidence and intensity of post-CABG pain.
MATERIALS AND METHODS This study was approved by the Institutional Review Board of Dow University of Health Sciences. We interviewed by phone a total of 116 patients who had undergone primary isolated CABG surgery from May 2012 to June 2013. The calls were made two days before the end of the patients’ one-month postoperative interval to inquire about the presence of postoperative pain. Out of 116 patients undergoing surgery during this time period, 46 had been operated by pedicled grafting while the remaining 70 had undergone skeletonized grafting. Out of the 46 pedicled-grafted patients, 29 stated on the phone that they had pain but only 27 reported at our hospital to participate in our study
48
BAWANY, ET AL. SKELETONIZATION REDUCES PAIN INTENSITY
for their pain evaluation. Two patients were excluded from the study as their pain was due to angina. Out of the 70 patients in the skeletonized group, 26 experienced pain and all of them reported for their pain evaluation. One patient chosen randomly from the skeletonized group was excluded from the study to have an equal number of participants from both the groups to enable fair comparisons. All the 50 patients gave written consent to take part in the study. Two interviewers were assigned the task of doing the pain evaluation from the patients at the one-month interval. The patients who were included in our study were unaware whether they had received skeletonized or pedicled grafts. The interviewers were also not aware whether they were interviewing skeletonized- or pedicled-grafted patients. The same 50 patients were also evaluated for their pain three months postoperatively by the same interviewers. The patients were questioned about the details of their pain using the Short Form McGill Pain Questionnaire (SFMPQ).7 The extent of disability was measured through the Pain Disability Index8 (PDI) and intensity of pain was measured through the 10-cm Visual Analogue Scale (VAS).9 The exact location of the pain was localized to one of the following: right anterior chest, left anterior chest, or midline. A number of aggravating factors were also inquired from the patients. Aggravating factors were scored out of a maximum of six points and included the following: walking, upper limb movement, deep breathing, touch, stress, and pressure put on the painful site.
J CARD SURG 2014;29:47–50
RESULTS Thirty-one patients were males (62%) and 19 (38%) were females. In the first month, the mean pain intensity measured through VAS was 30.4 4.0 and 55.0 5.7 mm in skeletonized and pedicled groups, respectively. The PDI score was 34.1 2.7 and 47.2 5.3 in skeletonized and pedicled groups, respectively. The mean scores calculated from SFMPQ were 9.3 1.0 and 13.8 2.0 in skeletonized and pedicled groups, respectively. The pedicled group had significantly higher scores measured by all three scales as compared with the skeletonized group (p-values < 0.0001) (Table 1). The scores for the three scales were again calculated in the third month for the same patients. Compared to the first month, the pain scores obtained were significantly less in the third month (Figs. 1–3). This significant reduction was observed in both groups as measured by repeated measure ANOVA (p-values < 0.0001). However, the pain scores from pedicled group were still higher than the skeletonized group (Table 2). Most of the pain felt by the patients was in left anterior chest wall (n ¼ 41, 82%). The majority of the patients observed mild pain (n ¼ 26, 52%). Some patients who underwent pedicled harvesting felt distressing (n ¼ 9) and few experienced horrible pain (n ¼ 3) while no patients in the skeletonized group suffered such type of pain. The number of aggravating factors was also significantly higher in the pedicled group (p ¼ 0.002) (Table 3).
THE FOLLOWING TECHNIQUES WERE USED IN SKELETONIZED AND NON-SKELETONIZED ITA HARVESTING After median sternotomy and removal of the thymic remnant, the ITA retractor was applied and the pleura was opened. In the nonskeletonized ITA, the dissection was started from down upwards and included division of the satellite veins and muscle using fine tip curved forceps and unipolar bovie electrocautery. In the skeletonized ITA, the dissection was started from upwards with ring tip fine forceps, fine tip scissors, and unipolar electrocautery at low levels. Papaverine injection was sprayed on ITA in both groups. None of the patients received narcotic pain medication upon discharge and none were taking narcotics at the time the questionnaires were performed. STATISTICAL ANALYSIS Data are presented as the mean and standard deviation for continuous variables and frequency with percentages for categorical variables. Chi-squared test was used to assess categorical variables. MannWhitney U-test was run to compare the pain scores and aggravating factors between skeletonized and pedicled groups. Repeated measure ANOVA was performed to observe change of pain scores at the first and third months in both groups. p-Values less than 0.05 were considered to be significant. All analyses were performed in IBM SPSS v. 21.0.
DISCUSSION The benefits of skeletonized harvesting include increased graft flow,10 increased graft length,11,12 and decreased incidence of mediastinitis.12 Another important benefit of skeletonized harvesting is the reduction in postoperative pain.6 Pain is a subjective sensation and has a major impact on the quality of life of patients. Studies have shown that persistent pain and dysesthesia lead to a significant reduction in quality of life.13 The results of our study indicate that post-CABG pain can have a serious effect on health-related quality of life as measured by the PDI score. Studies have shown that certain properties of ITA and the way in which it is harvested have a major impact on postoperative morbidity and pain.14 Our study indicates that the pedicled group had a significantly greater VAS, PDI, and SFMPQ score at one and three months follow-up.
TABLE 1 Scores Obtained by Visual Analogue Scale (VAS), Pain Disability Index (PDI), and McGill Pain Scale at First Month
VAS PDI McGill Pain Scale
Skeletonized
Pedicle
P-Value
30.4 4.0 34.1 2.7 9.3 1.0
55.0 5.7 47.2 5.3 13.8 2.0
