Innominate vein cannulation: easy but neglected technique

Introduction: Our experience in minimally invasive procedures and improvement of graft technology enables easy and successful operation carried out even with complex thoracic aortic diseases from limited surgical area. However, it should be more than one incision or cannulation site for such intervention. We aimed to present our experience and results of 23 patients who has ascending aorta and aortic arch pathologies of which we operated with J-shaped partial sternotomy and innominate vein cannulation. Methods: From January 2014 to January 2016, 23 patients with aorta and aortic valve pathologies who underwent aortic surgery with J-shaped partial sternotomy and innominate vein cannulation included. Operation findings, cardiopulmonary bypass (CPB) values, postoperative results, surgical mortality and morbidity rates, late conversion to full sternotomy rates, ICU and hospital length of stay were evaluated. Results: The mean age of the patients was 53.7±12 (range 19-68) and 18 (78.2%) were males. Arcus aorta debranching applied to 4 patients (17.3%) and one of these procedures was frozen elephant trunk procedure (4.3%). Neither mortality nor cerebrovascular accident occurred. Mean CPB peak flow was 4.6±0.4 L/min, mean flow index calculated as 2.01±0.38 L/min/m2 and there was no CPB problem intraoperatively. Innominate vein ligation was carried out in 5 patients but no complication was seen except one who had left arm swelling treated with elevation. Conclusion: Innominate vein cannulation with J-shaped partial sternotomy is a reliable and easily applicable method providing effective utilization of limited operative field not only in ascending aorta and aortic arch operations but also with the advancements of hybrid systems used in descending aorta pathologies.

to have chronic obstructive pulmonary disease (COPD). Cerebrovascular events that occurred more than 72 hours ago, correspond to cerebrovascular disease definition.

Patient selection
All patients were evaluated preoperatively with computed tomographic angiography (CT-A) for diagnostic purposes and determination of surgical indication. CT-A also provided valuable information about the level and anatomical suitability of the aortic root for the partial sternotomy procedure. Transthoracic echocardiography was used for the diagnosis of any valvular pathology  and in patients older than 40 years of age coronary angiographic evaluation was carried out for any possible coronary artery disease. In one patient with chronic type-1 aortic dissection, myocardial perfusion assessment was done with coronary CT-A.

Surgical technique
In all patients full monitoring was provided with central venous and arterial catheterizations and cerebral pulse oximetry. A cerebrospinal fluid drainage catheter was placed for pressure monitoring in the patient with chronic type-1 aortic dissection. Following the preparation of right subclavian artery, a J-shaped partial sternotomy was done through a limited skin incision with the ending zone at the level of fourth intercostal space. After the placement of pericardial traction stitches, ascending aorta and branches of aortic arch were prepared.  Table 3.
Postoperative outcomes are specified in Table 4. In-hospital mortality was not observed. None of the patients required revision surgery due to postoperative bleeding or cardiac tamponade. Only one patient with diabetes mellitus having a body mass index (BMI) of 35.6 kg/m 2 was reoperated for sternal dehiscence. Also none of the patients experienced a neurological or a pulmonary complication. Only one in 5 patients whose innominate vein has been divided, had swelling of the left arm that regressed with elevation before discharging from the hospital. We have not seen any vein complication such as bleeding, need for innominate vein ligation, vein thrombosis and upper arm edema etc. All patients had gone through CT-A and Echocardiographic evaluation before discharge and there were no pathologies on the images.

Statistical reviews
IBM SPSS Statistics 22 (IBM SPSS, Turkey) programs were used for statistical analysis when assessing the results obtained in this study. Descriptive statistical methods (mean, standard deviation, frequency) were used while data of the study were analyzing.

Discussion
Although median sternotomy with its proven reliability is the standard approach method for aortic valve and ascending aorta pathologies, in recent years minimally invasive methods such as right partial-thoracotomy or various complex partial sternotomy procedures have been taking over in search to lower surgical trauma and complications. [4][5][6] Those minimally invasive methods have comparably shorter ventilation times, lower transfusion rates, lesser post-operative pain, lower sternal dehiscence and wound infection rates, lower atrial fibrillation incidence, earlier mobilization and recovery periods leading to shorter hospitalization times. 1,2,5,7 Minithoracotomy and partial-sternotomy have similar post-operative results comparing to median sternotomy. However, they have longer CPB and cross-clamp times. Working in a deeper surgical field requires the use of specially-designed surgical instruments. 8 J-shaped 9,10 or T-shaped partial sternotomies provide better exposure in ascending aorta, aortic arch and aortic root operations. Nevertheless difficulty in fixation of the 3 fragments of sternum in T-shaped sternotomy makes the process more risky in terms of sternal dehiscence. 5 In minimally invasive surgery, to ensure the effective use of the limited surgical field, various cannulation techniques were described. 11 Albeit central arterial cannulation is more physiological, 12 in aortic pathologies including the aortic arch, its application is rather difficult. Therefore peripheral alternatives, such as axillary or femoral arteries are preferred. Femoral artery cannulation increases the risk of cerebrovascular event due to retrograde emboli especially in elderly patients with peripheral artery disease.13 During ascending aorta and aortic arch surgery with conventional median sternotomy, we perform open distal anastomosis with selective antegrade cerebral perfusion routinely due to its safety. Therefore we prefer the right axillary artery cannulation in our clinic. Femoral vein, right atrium, percutaneous internal jugular vein or superior vena cava are the common sites for venous cannulation. Femoral vein cannulation requires an additional incision and has its own complications. There is also a possibility of inadequate flow that would necessitate the insertion of an extra cannula through superior vena cava or right atrium resulting in narrowing of operative field.11 During right atrial cannulation, passing out the venous cannula through a subxyphoidal skin incision might be difficult in patients with stretched or deeply placed right atrium. 14 IJV cannulation, achieved by the insertion of smalldiameter cannulas either with Doppler guide or Seldinger Table 2. Operative techniques and surgical information

Procedures Performed No. (%)
Ascending aorta replacement   19 Interruption of venous return may result in swelling of the left upper extremity and cerebral edema leading to neurological complications, both of which regress with elevation therapy. In our study we observed left arm swelling in only one patient, which returned to normal with elevation and the patient was discharged without any problem.
Although it was a retrospective study with small number of patients, we believe that innominate vein cannulation technique is successful if it is applied systematically in accordance with the conventional CBP principles. Innominate vein cannulation with J-shaped partial sternotomy is a reliable and an easily applicable method enabling effective utilization of narrow operative field not only in ascending aorta and aortic arch operations but with the advancements of hybrid systems also in descending aorta pathologies.

Ethical approval
This study was approved by the local ethics committee (No. 2018.7/3-127).

Competing interests
There are no financial or other relations that could lead to a conflict of interest. There are any non-financial competing interests (political, personal, religious, ideological, academic, intellectual, commercial or any other) to declare in relation to this manuscript.  Hospital stay (Mean ±SD, min-max day) 6.6±1.9 (4-11) Pulmonary complications; >3 days of ventilator support or tracheostomy, Renal insufficiency; postoperative creatinine level >2.5 or temporary/ permanent dialysis requirement, ICU; Intensive care unit, SD; Standard deviation, min; minimum, max; maximum.