Three Part Question
Does [pleurotomy] during [IMA harvest] increase the incidence of [post-operative pulmonary complications]?
You are a first year cardiothoracic registrar who is starting to work for a consultant surgeon who always prefers the pleura to remain intact whilst harvesting the internal mammary artery (IMA). The surgeon avoids pleurotomy to reduce pulmonary complications after cardiac surgery, but you wonder whether there is any evidence in the literature to support this practice
Medline 1966-Oct 2004 using the OVID interface.
[cardiac surgery.mp OR CABG.mp OR coronary art$ bypass graft$.mp OR cardiopulmonary bypass.mp OR exp cardiovascular surgical procedures/ OR heart surgery.mp OR LIMA.mp] AND [exp Pleura/ OR Pleura$.mp OR extrapleur$.mp OR pleurotomy.mp]
One hundred and fifty-four papers were found of which 19 were relevant. Eleven papers were discounted as they did not compare IMA harvest with intact pleura versus IMA harvest with open pleura, and thus did not directly address the question. There were no meta-analyses on this topic. Three RCTs were identified and the remainder were all cohort studies with small sample/population sizes. These are presented in the table
|Author, date and country
||Study type (level of evidence)
|Ali et al,|
|280 patients for elective coronary revascularization using IMA
Group I (n=30) pleura intact
Group II (n=50) pleurotomy||Single centre PRCT (level 1b)||Pleural effusion on days 0 and 3||Group I 7/130. Group II 30/150 P<0.001||No effusions required tapping
5 group II patients required opening for tamponade
Preop FEV1 <80% excluded
Significant pneumonia or atelectasis defined as need for antibiotic therapy or ventilatory support|
|Postoperative bleeding||4% in both groups|
|Significant pneumonia or atelectasis||None in both groups|
|Hospital stay||Group I 6-10 days. Group II 6-10 days. No significant difference|
|Wimmer-Greinecker et al,|
|112 patients for coronary revascularization
Group A (n=57) pleurotomy
Group B (n=55) pleura intact||Single centre PRCT (level 1b)||Blood loss||Group A 608±58 ml. Group B 470±48 ml P=0.027|
|Lung function||Greater reduction in FEV1 (Group A 76.0%±1.6 vs Group B 83.2%±1.6; p=0.002). FEV1/FVC (Group A 0.771±0.021 vs Group B 0.832±0.02; P=0.003)|
|Pleural effusion and atelectasis||Effusion A=52.6%, B=23.6% (P=0.002). Atelectasis A=42.1%, B=20% (P=0.015)|
|Noera et al,|
|433 CABG with IMA
Group 1: Open pleura
Group 2: Extrapleural takedown with pleura intact||Single centre PRCT (level 1b)||Transfusion requirements||Significantly lower transfusion rate in group 2|
|Postop effusions, elevated hemidiaphragm||Lower but not significant rates of effusion and elevated hemidiaphragm in group 2 vs 1|
|Bonacchi et al,|
|299 elective patients undergoing coronary revascularization
Group I (n=80) skeletonized IMA, intact pleura
Group II (n=179) pedicled IMA, open pleura
Group III (n=30), skeletonized IMA, open pleura||Cohort study (level 2b)||Mechanical ventilation time||Significantly longer in groups II (6.2±2.9 h) and III (6.0±1.1 h) vs I (5.4± 1.2 h); P<0.018, P<0.02 respectively||EF <30% excluded
12 in group I with repair of pleura
Decision to skeletonize IMA based on surgeon's experience
If there were small breaches of the pleura these were repaired and included in group I
Analysis only for surviving patients; 2 died in group I, 7 in II, 1 in III|
|Pmax >20 cm H2O||Significant difference in group II (3.2±1 h) vs I (2.3±0.6 h) P=0.001|
|Prolonged ventilation (>24 h)||Significant difference in group II (16/179) vs I (1/80) P=0.03|
|Pleural effusion||Significant difference in group II (31/186) vs I (5/82) P=0.011|
|Thoracocentesis||Significant differences in groups II (31/179) and III (7/30) vs I (5/80) (P=0.027, P<0.027, respectively)|
|Atelectasis during ICU||Significant difference in group II (37/179) vs I (6/80) P<0.013|
|Intensive care stay||Group I 1.03±0.5 d. Group II 1.4±0.7 d. Group III 1.35±0.4 d. I vs II P=0.005. I vs III P=0.002|
|Landymore et al,|
Group 1: 39 valve/SVG
Group 2: 34 IMA + pleurotomy
Group 3: 33 IMA pleurae intact||Cohort study (level 3b)||Diaphragmatic elevation a) prior to discharge||1-21%; 2-77%; 3-24%||No statistical analysis|
|Diaphragmatic elevation b) at three months||1-5%; 2-47%; 3-6%|
|Pleural effusions a) prior to discharge||1-26%; 2-91%; 3-58%|
|Pleural effusions b) at three months||1-3%; 2-15%; 3-0%|
|Tomita et al,|
|99 elective CABG
Group 1: 45 BIMA + pleurotomy
Group 2: 45 IMA + pleurotomy
Group 3: 9 IMA/SVG no pleurotomy||Cohort study (level 3b)||PFTs and CXR post op||No CXR differences between 3 groups. All patients had significant reductions in PFTs but no differences between groups|
|Rolla et al,|
|57 IMA patients
Group 1: 32 with pleurotomy
Group 2: 25 pleurae intact||Cohort study (level 3b)||Atelectasis on POD 2&6 CXRs||1–22% & 29%; 2–19% & 19% Not significant||Small study. No clinical data.
Data described as a percentage of preop value.
There was no significant difference in preop values between the two groups.|
|Pleural Effusion on POD 2&6 CXRs||1–74% & 48%; 2–52% & 38%; Not significant|
|Raised hemidiaphragm on POD 6 CXRs||1–18.5%; 2–14%; Not significant|
|PFTs 2 months postop||VC: 1–86.8±1.97; 2–93.6±1.65; P=0.05. FEV1: 1–84.6±1.82; 2–90.9±1.41 P=0.02|
|Lim et al,|
|206 elective patients
Group I Routine or incidental pleurotomy (n=164)
Group II Pleura intact (n=38)||Cohort study (level 3b)||Left lung atelectasis||Significantly higher in pleurotomy group (67.7%) vs intact pleura (45.2%) P=0.007.||Heterogeneous group
Small intact pleura group|
|Effusion||Pleura intact 46%. Pleura open 43%. P=0.66|
|Hospital stay||9 days both groups|
The majority of relevant studies assessed the effect of pleurotomy on post-operative lung function, ventilatory requirements and radiographic changes. Only three studies considered the effect of pleurotomy on clinical outcome [Norea, Lim and Ali et al]. In addition, the lengths of post-operative follow-up varied extensively from 30 min to 3 months. We identified three PRCTs that compared IMA plus pleurotomy to IMA without pleurotomy.
The largest PRCT was conducted by Noera et al, the only significant outcome being greater transfusion requirements in the pleurotomy group, although they did find that the rate of pleural effusion and raised left hemidiaphragm was greater albeit not significant in the same group. This study is further supported by Ali et al and Wimmer-Greinecker et al. In the study undertaken by Ali et al., they found that the pleurotomy group had significantly more pleural effusions but that this did not result in more thoracocenteses. Pleurotomy also safe-guarded against the development of cardiac tamponade, with 5 in the closed group but none in the open pleura group. Another clinically relevant outcome was that hospital stay was not different between the two groups.
Lim et al assessed post operative chest radiology and length of stay in a heterogeneous group that comprised 138 CABG, 39 valve replacements and 29 CABG + valve replacement. Patients were divided into those with pleurotomy(n=164) and those without (n=42). The pleurotomy group had significantly more atelectasis (67.7% vs. 45.2%, P<0.007) but there was no difference in rates of consolidation, effusion or length of stay.
In a relatively small study, Rolla et al recruited 57 patients all of whom had an IMA conduit, therefore blinding chest radiograph reporting. The two groups were of similar size, 32 with pleurotomy, 25 without. There was no difference in post-op chest radiograph on day 2 or 6 and all patients were found to have significantly worse PFTs persisting at 2 months post operation.
Tomita et al divided 99 elective CABG cases into 45 BIMA + pleurotomy, 45 IMA + pleurotomy and 9 IMA/SVG only with no pleurotomy and studied PFTs and post-operative chest radiograph changes. There were no differences between groups with all patients suffering significant reductions in PFTs.
Clinical Bottom Line
All patients undergoing cardiac surgery suffer a significant deterioration in Pulmonary Function tests and chest radiograph appearance post-operatively. Pleurotomy seems to compound this with increased rates of atelectasis and pleural effusions, although no impact on clinical outcome or length of hospital stay has been demonstrated.
- Ali IM, Lau P, Kinley CE, Sanalla A. Opening the pleura during internal mammary artery harvesting: advantages and disadvantages. Can J Surg 1996;39:42–45.
- Wimmer-Greinecker G, Yosseef-Hakimi M, Rinne T, Buhl R, Matheis G, Martens S, Westphal K, Moritz A. Effect of internal thoracic artery preparation on blood loss, lung function and pain. Ann Thorac Surg 1999;67:1078–1082.
- Noera G, Pensa PM, Guelfi P, Biagi B, Lodi R, Carbone C. Extrapleural takedown of the internal mammary artery as a pedicle. Ann Thorac Surg 1991;52:1292–1294.
- Bonnacchi M, Prifti E, Giunti G, Salica A, Frati G, Sani G. Respiratory dysfunction after coronary artery bypass grafting and employing bilateral internal mammary arteries: the influence of the intact pleura. Eur J Cardiothorac Surg 2001;19:827–833.
- Landymore RW and Howell F. Pulmonary complications following myocardial revascularization with the internal mammary graft. Eur J Cardiothorac Surg 1990;4:156–161.
- Tomita S, Sakata R, Umebayasi Y, Miyata A, Terai H, Ueyama K, Uezu T. Study of pulmonary function after CABG with pleurotomy. Jpn J Thoracic Surg 1994;47:528–532.
- Rolla G, Fogliati P, Bucca C, Brussino L, Di Rosa E, Di Summa M, Comoglio C, Malara D, Ottino GM. Effect of pleurotomy on pulmonary function after coronary artery bypass grafting with internal mammary artery. Respir Med 1994;88:417–420.
- Lim E, Callaghan C, Motalleb-Zadeh R, Wallard M, Misra N, Ali A, Halstead JC, Tsui S. A prospective study on clinical outcome following pleurotomy during cardiac surgery. Thorac Cardiovasc Surg 2002;50:287–291.