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 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 12  |  Issue : 1  |  Page : 8-12

Trans-thoracic open ligation of the persistent ductus arteriosus in Ile-Ife, Nigeria


1 Department of Surgery, Cardiothoracic Surgery Unit, Obafemi Awolowo University, Ile-Ife, Nigeria
2 Department of Surgery, Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria
3 Department of Paediatrics, Obafemi Awolowo University, Ile-Ife, Nigeria
4 Department of Anaesthesia, Obafemi Awolowo University, Ile-Ife, Nigeria

Date of Web Publication5-Jan-2015

Correspondence Address:
Uvie U Onakpoya
Department of Surgery, Cardiothoracic Surgery Unit, Obafemi Awolowo University Ile-Ife 220005
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0189-7969.148479

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  Abstract 

Background: Surgical ligation of a patent ductus arteriosus (PDA) is often the only available option in resource-poor countries such as Nigeria in order to prevent pulmonary hypertension and other complications of a patent ductus.
Objective: The purpose of our study was to review our surgical experience, highlighting our techniques at a University Teaching Hospital in Nigeria.
Materials and Methods: This is a retrospective audit of the patients who had trans-thoracic open surgical (TTOS) patent ductus ligation over a 5-year period (2009-2013).
Result: Sixteen patients (2 boys and 14 girls) aged 4 months-19 years (Mean = 7.1 ± 6.7 years) had TTOS PDA ligation utilizing a triple suture ligation technique. Only three (18.8%) were asymptomatic pre-operatively. Eleven (68.9%) had isolated PDA and others had associated cardiac and extracardiac lesions. The most common post-operative complication was chylothorax, which occurred in two patients (12.5%), and most patients (75%; n = 12) were discharged home by the 5 th post-operative day.
Conclusion: Careful attention during transthoracic open surgical closure of the persistent ductus arteriosus will ensure a safe procedure associated with relatively few complications and short post-operative hospital stay.

Keywords: Chylothorax, persistent ductus arteriosus, serratus anterior-sparing posterolateral thoracotomy, triple suture ligation


How to cite this article:
Onakpoya UU, Ogunrombi AB, Aladesuru AO, Okeniyi JA, Adenekan AT, Owojuyigbe AM. Trans-thoracic open ligation of the persistent ductus arteriosus in Ile-Ife, Nigeria. Nig J Cardiol 2015;12:8-12

How to cite this URL:
Onakpoya UU, Ogunrombi AB, Aladesuru AO, Okeniyi JA, Adenekan AT, Owojuyigbe AM. Trans-thoracic open ligation of the persistent ductus arteriosus in Ile-Ife, Nigeria. Nig J Cardiol [serial online] 2015 [cited 2019 Jul 16];12:8-12. Available from: http://www.nigjcardiol.org/text.asp?2015/12/1/8/148479


  Introduction Top


The ductus arteriosus is a vascular structure essential for intra-uterine fetal survival; it connects the isthmus of the aortic arch to the roof of the main pulmonary artery near the origin of the left pulmonary artery due to persistence of the distal portion of the embryonic 6 th aortic arch. It normally closes spontaneously within 24-48 hours after birth by the contraction of medial smooth muscle in the vessel wall, due to the increased oxygen tension and reduced prostaglandin E2 and I2 levels. Failure of this spontaneous closure of the ductus arteriosus by the age of 3 months results in a persistent or patent ductus arteriosus (PDA). [1],[2] Trans-catheter closure has been established to be the method of choice for treating PDA with very good outcomes, and it is effective and safe with complete closure rates of 90-95% in most studies. [3],[4],[5],[6] However, surgical closure remains the method of choice for treating very large PDAs not amendable for catheter intervention [2] as well as in resource-poor communities that either lack a cardiac catheterization laboratory or if present, the costs are prohibitive. Since the first trans-thoracic surgical ligation in 1938 by Gross [7] experience has proven the efficacy of surgical ligation or division and its associated very low mortality. [8],[9]

Bhati and colleagues were the first to use a balloon catheter (Fogarty) to seal the PDA from inside during suturing of the patch around the PDA ostium, [10] a technique that has been adopted by others. [11],[12] Rarely, a large, window-type PDA may have insufficient length to permit ligation, and the appropriate surgical procedure would be a patch closure of the pulmonary end of the ductus under cardiopulmonary bypass. [13],[14]

Thoracoscopic clipping of the patent duct has a very good outcome and very low mortality rates, [15] and without many of the complications of the open technique since it does not involve rib retraction, post-operative pain, bleeding, and long-term chest wall deformities are avoided. [16] However, in situations where severe bleeding complicates the procedure such as in a torn ductus, reversion to an open trans-thoracic method is mandatory.

The purpose of this study is to review our experience with trans-thoracic open surgical ligation of the PDA in some Nigerian patients at our institution with a view to highlighting important surgical operative steps to reduce morbidity.


  Materials and methods Top


This study is a descriptive retrospective analysis of the records of all patients with echocardiographic diagnosis of PDA who had transthoracic ductal ligation between March 2009 and July 2013 at a University Teaching Hospital in Nigeria. All patients had invasive monitoring using a central venous catheter and either a radial or a femoral arterial lines. A 5-8-cm left serratus anterior-sparing posterolateral thoracotomy was done and access to the PDA was obtained via the 4 th intercostal space after retracting the left lung medially and inferiorly. The mediastinal pleura was incised lateral to the vagus nerve and the ductus was mobilized by a combination of blunt and sharp dissections superiorly and inferiorly and around the aortic end of the PDA; the recurrent laryngeal nerve was identified looping around the inferior margin of the duct and preserved. The mobilized ductus was then ligated at the pulmonary and aortic ends with either silk 0 or 1 suture depending on the size of the PDA. Additionally, the mid portion between these two sutures was suture-ligated using suitably sized polypropylene sutures (size 5/0 or 4/0 depending on the size of the ductus) after taking a few bites of the ductal wall between the ligated ends. This triple ligation was done for all patients except for an 18-year-old girl with a torn ductus who was offered four suture ligations of the ductus using 3/0 polypropylene sutures. Successful ductal ligation was confirmed by a slight rise in the radial or femoral arterial blood pressure and the absence of a thrill in the region of the ligated ductus. Unipolar diathermic coagulation was applied to the edges of the mediastinal pleura to seal off possible lymphatic radicles and the edges were then approximated loosely using polypropylene sutures. An intercostal tube was inserted through the 6 th or 7 th intercostal space under vision and connected to an underwater drainage system. The tubes were usually removed by the 2 nd or 3 rd post-operative day after a chest radiograph confirms absence of left-sided pleural collections.

The demographic details, clinical parameters, investigations, and surgical techniques were retrieved from the main theatre register and hospital record archives and were analyzed using SPSS version 21 software (IBM Statistics, 2012).


  Results Top


Sixteen patients were operated upon within the period of the study, with a mean age of 7.1 years (range = 4 months-19 years) and a male:female ratio of 1:7 [Table 1]. The most prevalent symptoms were dyspnea and recurrent respiratory tract infections present in 12 patients each (75%), while the presentation was asymptomatic in 3 patients (18.8%) because of machinery murmur and cardiomegaly on routine pre-school evaluation [Table 1]. Seven patients (43.8%) had symptoms from birth while 5 patients (31.3%) had their symptoms traced to greater than 6 months. Although 11 patients (68.8%) had no associated congenital anomalies, 5 (35.7%) had co-existing anomalies with 2 (12.5%) having ostium secundum type atrial septal defects while 1 each (6.2%) had kyphoscoliosis, Down's syndrome and combined anorectal malformation and bilateral absent femur [Table 1]. Preoperative echocardiographic assessment showed a PDA size greater than 10 mm in 10 patients (62.4%), of which two were about 20 mm while 5 patients (31.3%) had PDA less than 10 mm [Table 2]. The size was not measured in one patient (6.3%). Only three patients (18.8%) had their surgeries within a week of diagnosis while 8 (50%) waited for 1-6 months since diagnosis before having their PDA ligated [Table 2]. The reasons for delay were mainly financial and treatment of ongoing respiratory tract infection. Serratus anterior-sparing posterolateral thoracotomy with triple suture ligation through the left 4 th intercostal space was utilized in all patients. All patients except one (6.3%) had a post-operative ICU stay of 1 day while post-operative hospital stay ranged between 3-27 days [Table 2]. Most patients (n = 12; 75%) were discharged home within 5 days of surgery while three patients (18.8%) were on admission for between 14 and 27 days for management of complications following surgery [Table 2]. Complications were experienced by 5 patients (31.3%) with the most common being chylothorax seen in two patients (12.5%). One patient each had recanalization, septicemia, and severe acute gastric erosions, which led to death in 2 patients.
Table 1: Patient characteristics

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Table 2: Peri-operative features and post-operative complications

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  Discussion Top


The persistent ductus that is not a component of a duct-dependent circulation is usually recommended for closure at least 3 months after birth, sooner, or in the neonatal period if it is associated with congestive cardiac failure, severe respiratory tract infection or failure to thrive. [17],[18],[19] Closure is advocated to prevent the long-term complications of recurrent respiratory tract infections, congestive cardiac failure, infective endocarditis, irreversible pulmonary hypertension, and aneurysmal dilatation amongst others. [17] Since it is a congenital problem, most patients' symptoms are usually traceable to shortly after birth when they may have diaphoresis, interruption of feeds, and recurrent respiratory tract infection. This early symptomatology occurs with large patent ducts while children with smaller ducts may be asymptomatic and therefore present only later in life. [19] This may account for reasons why only 43% (7 patients) had symptoms from birth [Table 1]. Indeed, 3 of the patients were asymptomatic and 2 of them were only sent for echocardiography due to pre-school chest X-ray findings of cardiomegaly while one patient was discovered to have a machinery murmur while being evaluated for repair of a hernia.

The clinical suspicion of a PDA should prompt definitive evaluation usually by a trans-thoracic echocardiography, which will show a jet of blood flowing from the proximal descending thoracic aorta to the proximal left pulmonary artery. Echocardiography may also reveal other intracardiac anomalies associated with a PDA such as various septal defects as well as volume changes in the ventricles; this information is critical to the surgeon in planning the surgical procedure. Two of our patients had co-existing ostium secundum-type atrial septal defects and they presented to us in infancy. Ostium secundum atrial septal defect is usually indicated for intracardiac repair or device closure after the age of 3 years because of the propensity for spontaneous closure in some children. [20],[21] We ligated their patent ductus and observed their atrial septal defects (ASD) over time with serial echocardiography. Fortunately, the ASDs closed spontaneously three and seven months respectively after PDA ligation. While preoperative echocardiographic PDA size determination is useful for surgical planning, we observed that the actual size at surgery was usually larger. This probably is because of the 2D echocardiography machines used to estimate the size of a 3D structure; the preoperative size determination however may be useful in ruling out aneurysmal ducts.

Trans-catheter device closure or coil occlusion is now the primary procedure for closure of the persistent duct worldwide as it is associated with avoidance of a thoracotomy incision and has comparable mortality rates. Transcatheter occlusion is not widespread in Nigeria [6] because of its prohibitive costs compared with open ligation and paucity of trained personnel and equipment; therefore, all our patients had a transthoracic open duct ligation under general anesthesia and invasive monitoring.

A serratus-anterior sparing posterolateral thoracotomy is our choice and it was utilized in all cases as it spares one of the assessory muscles of respiration and may account for better post-operative respiratory functions as advocated by several authors. [22],[23] Indeed, Alar and colleagues showed that patients who underwent a thoracotomy with sparing of at least one of the accessory respiratory muscles had better quality of life as measured by the Short-form-36 health survey. [24] Also, because of the observed musculoskeletal deformities such as scoliosis six years after standard muscle cutting posterolateral thoracotomy in children, some authors passionately advocated that at least one of the muscles be spared. [23],[25] The belief that access would be compromised by a muscle-sparing incision has been shown to be unfounded [22],[23] and we had enough access in our surgeries after adequate mobilization of the serratus anterior muscle.

We usually mobilized the ductus cranially and caudally by a combination of blunt and sharp dissections however in a 19-year-old female with a very large PDA (about 30 mm), we had to isolate the PDA using the exclusion technique as described by Khonsari and Sintek, [26] by first passing a heavy silk suture around the aorta proximal to the PDA and then retrieving one end below the duct after passing that end around the portion of the aorta just distal to the duct. The duct was mostly triple ligated to reduce the incidence of recanalization and recurrence. Recanalization is a known complication of the closure of a patent ductus by any method. Some surgical series have reported recanalization rates of 0-2% following ductal division, [27],[28] 3.1% after triple ligation [29] and between 5-23% for double and single ligations. [30],[31] We however had a case of post-operative recurrent duct in an 18-year old girl who had a torn ductus intraoperatively; dealing with the ductus in the usual manner was difficult due to bleeding so a mass suture ligation of the duct was done. She had a small residual PDA and she was referred for device closure at the only institution in the country offering that service, in line with the recommendations of some authors, [32],[33] because operative dissection of the area of the ductus will be associated with more complications of bleeding due to the adhesions that would have occurred following the index surgery.

Chylothorax was observed in two patients; one was a 5-year-old boy had a massive left chylous collection, which was treated by thoracic duct ligation after failed conservative management, while the second case was a small chylous leak that was managed conservatively with fat restrictions, which led to its resolution 9 days later. Chylothorax is a known complication of transthoracic PDA closure either thoracoscopically or by the open method. [34],[35],[36],[37] It is due to leakage from the many lymphatic radicles in the mediastinal pleura and around the hilum of the left lung. Since the mediastinal pleura is divided to gain access to the PDA, there is a potential for these radicles to leak into the left pleural space and cause a chylothorax. Intra-operative prevention involves limiting the dissection to only the region of the ductus and diathermic coagulation of the edges of the divided mediastinal pleura. This can significantly reduce the incidence of post-operative chylothorax. We have adopted this strategy in all our cases after our first case of chylothorax.

Transthoracic ductal closure is a safe procedure with low mortality of less than 2% in most series. [27],[28] We had two mortalities in this series, though these were not as a direct result of surgery. The first, a 4-month-old girl with recurrent severe bronchopneumonia and congestive cardiac failure who needed urgent ligation of the duct but died 3 days later due to cardiorespiratory failure complicating septicemia. The second case was a 13-year-old girl who had uneventful surgical closure but developed massive upper gastrointestinal bleeding due to extensive gastric erosions 8 hours after surgery following one dose of the intramuscular non-steroidal inflammatory drug diclofenac, which was administered as part of our protocol for post-thoracotomy pain control. Since the death of this patient, we had to revise our protocol to avoid this drug; patients are now managed on opioids and intravenous paracetamol in addition to intercostal nerve blocks, and we have not had a recurrence of this complication in any post-thoracotomy patient.


  Conclusion Top


Trans-thoracic ligation of a PDA is a simple and safe procedure and should halt the natural history of a patent ductus and lead to a reversal of the volume changes in the heart. In settings where trans-catheter devices are either unavailable or their costs prohibitive, open surgical ligation is advocated as early as after 3 months of age. Surgical complications of ductal ligation may occur but good surgical technique and prompt management of these complications would lead to good early and late outcomes.

 
  References Top

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