Authors: Priyanka Ramesh  ( Department of General Surgery, Patel Hospital, Karachi, Pakistan. )
Aniqa Saeed  ( Department of Urology, Aga Khan University Hospital, Karachi, Pakistan. )
Muniza Nusrat  ( Department of General Surgery, Patel Hospital, Karachi, Pakistan. )
Sehrish Batool  ( Department of General Surgery, Patel Hospital, Karachi, Pakistan. )
Hina Khan  ( Department of General Surgery, Patel Hospital, Karachi, Pakistan. )
Ghulam Murtaza  ( Department of General Surgery, Patel Hospital, Karachi. )

Objective: To determine the incidence of complications [Surgical site infection (SSI), intra-abdominal abscess (IAA), stump leak] related to stump ligation with manual loop of sliding extracorporeal suture knot in laparoscopic appendectomy.

Methods: This cohort study was conducted on patients who underwent laparoscopic appendectomy from June 2014 to November 2020 performed by the same surgeon with almost similar technique. Stump was ligated with manual loops, applied by the surgeon or trainee or both (one by surgeon and other by trainee). SSI and IAA were classified according to Centers for Disease Control and Prevention (CDC) criteria.

Results: Total 120 patients were included with median (Interquartile range, IQR) age of 24 (19-35) years and male predominance i.e. 81 (67.5%). Median (IQR) for the duration of symptoms, time from presentation to surgery and duration of surgery was 2(1-4) days, 10 (4-15) hours and 60 (44-70) minutes, respectively. SSI was documented in 9(7.5%) patients, managed by wound hygiene and antibiotics. IAA was observed in one(0.8%) patient who required readmission for antibiotics and radiology guided drain placement. No stump leak was observed.

Conclusion: Manual endo-loop is a safe, reliable and cost effective technique for stump ligation in LA, and can safely be incorporated into teaching of surgical trainees.

Keywords: Surgical Site Infection, Intra Abdominal Abscess, Endoloop, Stump leak, Clips, Stapler.

 

Introduction

 

Acute appendicitis is a common abdominal emergency dealt by general surgeons¹ with cumulative incidence of 7% in general population.² Appendectomy is the standard of care. First reported¹ by a German gynecologist Kurt Semm in 1983, laparoscopic appendectomy (LA) has been gaining widespread acceptance due to various reasons i.e. accurate diagnosis, less morbidity and early return to activity. However, the main limiting factors are the equipment (availability & cost), learning curve and surgeons' resistance to acquire a new technique.

Apart from the laparoscopic equipment; trocars (if disposable), energy devices and ligation of the base of appendix determine the cost of treatment. Reusable metallic trocars and bipolar devices can curtail much of the cost. The stump can be dealt with any one of the several ways like staplers, clips (titanium, Hem-o-lok), commercial endo-loop, manual loop, intracorporeal ligation, extracorporeal sliding knot, bipolar cautery and ligasure. The decision of choosing any one of these tools is based on several factors i.e. reliability, cost, technique, duration of surgery and applicability to distended appendix.³ In a meta-analysis by Antoniou et al.,⁴ suture ligation was found superior to others.

Since presently, LA is the first step of a surgical trainee in the world of minimally invasive surgery; a mentor/ supervisor has to be vigilant about patient safety and cost. In general, one commercial endo-loop is applied at the base of appendix and supervisor feels comfortable in applying it with himself / herself to avoid a leakage. If one extra endo-loop is applied for the training purpose, it would increase the cost and poses an ethical dilemma. Hence, a manual loop can serve that purpose, where more than one manual loops can be prepared from a single polyglactin (vicryl) suture. Manual loop has been compared to commercial endo-loop with no significant difference in morbidity.⁵ This improves the knotting technique as well as hand eye coordination of the trainee while applying the loop and also encourages the mentor to train the future surgeon without additional cost and concerns.

The objective of this study was to determine the incidence of complications (SSI, IAA, stump leak) after appendiceal stump ligation with manual loop of sliding extracorporeal suture knot in laparoscopic appendectomy at a tertiary care hospital.

 

Patients and Methods

 

This cohort study was conducted at the Department of General Surgery, Patel Hospital Karachi, Pakistan. Patel hospital is 200 bedded; not-for-profit tertiary care hospital and an academic institution with post graduate programme in general surgery and other disciplines. Patients (12 years and above) who underwent LA between June 2014 and November 2020 were included in the study. Exclusion criteria was: a) LA with stump closure other than manual extracorporeal suture knot i.e. intracorporeal knot, stapler or clip; b) conversion to open; c) other concomitant abdominal surgery; d) any other pathology encountered during surgery; e) lost to follow up.

After the approval by Ethical Review Committee of Patel Hospital Karachi in May 2016, the data collection commenced and had to be continued till December 2020 in order to collect a substantial number of cases. The data of the patients i.e. demographics, operative details, histopathology and clinic follow up were maintained in the HIMS (Hospital Information management System) and intermittently recorded on a proforma by surgical residents.

The cases were performed under general anaesthesia by the same general surgeon with almost a uniform technique. Patient was asked to void just before the procedure. Ceftriaxone (3rd general cephalosporin) was used in majority of patients. After skin preparation with povidine iodine, a 10-mm optical port was inserted above the umbilicus, followed by a 5-mm port in the suprapubic midline region. The second 10-mm port was inserted either in the midway between the first 2 ports and to the left of the rectus abdominis muscle in left iliac fossa or in right upper quadrant, depending on the body habitus. Patient was placed in Trendelenburg's position with leftward tilt and terminal ileum was swept medially. Appendix was located by either following the ligament of Traeves or taeniae coli. Depending on the variety of findings, the meso-appendix was dealt with combination of blunt dissection, diathermy and clipping. The manual loop with extracorporeal knot on '0' size polyglycolic acid (Vicryl) suture was prepared by surgeon or trainee as shown in Figure-1.

 

 

A trainee had to practice the knot till the knot preparation time was within 20 seconds. Manual loops (upto three in number) were applied either by the surgeon or trainee or both (one by surgeon and other by trainee).

Suture knot was pushed via port through a fascial dilator (14F, 25cm, Boston Scientific) or Johan forceps. First loop was tightened around the base of appendix, approximately 2-5mm distal to cecum, with a slow and steady pressure till the appendicular tissues started blanching. In most of the cases, one more loop was applied few millimeters distal to the first one. After transacting the appendix above the sutures, specimen was withdrawn into the 10 mm port and retrieved out of the body. If the specimen was too thick to be retrieved via 10mm port, a glove bag was used to retrieve it after dilating the optical port. Wounds were closed with vicryl 3-0 subcuticular or prolene 3-0 interrupted vertical mattress sutures.

Post operatively, patients were kept nil per os upto 6-24 hours depending on the findings and the course. Antibiotics were discontinued after two post-operative doses in clean cases or continued for three post-operative days in contaminated or dirty cases with frank pus or perforation or gangrene. Daily surgical sites were assessed by the registrar of surgery and/or consultant surgeon till discharge from hospital. Patients were discharged once they were mobilized, passed flatus/stool and tolerated soft diet. After discharge, there was a weekly follow up at the outpatient clinic by the consultant surgeon till the wounds healed completely. If SSI was found in closed wounds, the sutures were removed, daily dressing was done either by the patient, family or a visiting home health care provider till the wound healed completely.

The primary outcome variable was intra-abdominal abscess (IAA) or stump leak. IAA labelled if the patient had persistent fever >100° F, abdominal tenderness, diarrhoea or ileus (vomiting, constipation, abdominal distension and absent bowel sounds); and ultrasound or CT scan reported a fluid collection. Leak was labelled if contrast study (CT scan or follow through) confirmed the stump leak or if stump leakage was confirmed on re-exploration.

The secondary outcome variables were SSI and duration of surgery. SSI was assessed according to criteria of the Centers for Disease Control and prevention (CDC)6, within a period of at least 30 days postoperatively. Duration of surgery was recorded as time from incision to dressing.

Data was checked for wild codes and internal consistency with frequency tables and cross tabulations. Continuous variables were analyzed as means ± standard deviation for data with normal distribution and median with inter-quartile ranges for skewed data. Categorical variables were analyzed as proportions and percentages.

 

Results

 

Total of 120 patients were included in the study (Figure-2) with median (Interquartile range, IQR) age of 24 (19-35) years and male predominance i.e. 81 (67.5%). Median (IQR) for the duration of symptoms, time from presentation to surgery and duration of surgery was 2(1-4) days, 10 (4-15) hours and 60 (44-70) minutes, respectively (Table-1) Median (IQR) hospital stay was 1 (1-2) days. Average time required to prepare a manual loop was 20±1.9 seconds.

 

 

 

 

 

 

Nine out of 120 patients developed complications. SSI was documented in 9(7.5%) patients in supra-umbilical port, managed by wound hygiene and antibiotics. One patient, who had perforated appendix with purulent fluid around it, developed SSI as well as IAA at 6th post-operative day. CT scan with oral and intravenous contrast confirmed the IAA without a stump leak, that was managed by radiology guided drain placement. He was readmitted due to a need for intravenous antibiotics (Piperacillin/tazobactam) to cover multi drug resistant organism. Stump leak was not encountered in any of the patients.

 

Discussion

 

In this study, SSI was observed in 7.5% patients after LA with manual loop and IAA in only one patient; neither stump leak nor re-operation was reported in any of the patients; thus, reiterating the safety and cost effectiveness of manual loop

In LA, there are several ways of closing the base of appendix. Different variables are to be considered while choosing the best technique i.e. safety, applicability, duration, reliability and cost. Stapler is easy to use, has the least complications of all and applicable to inflamed appendiceal base; however, the cost limits its utility in most of the healthcare systems.^6,7 Besides, it requires a 12mm port to apply the stapler, which is more costly and painful than a 5mm port. On the other hand, hem-o-lock clips are feasible and cost effective;^8-10 however, in these studies the patients with wide base were ligated with alternate techniques like stapler or endo-loop and excluded. Hue CS et al found that hem-o-loks are unsafe for severely inflamed appendiceal base >10mm,8 where it increases the risk of pressure necrosis and leak owing to forceful application to lock the clips.

Titanium clips (TC) are also investigated with results comparable to the suture ligation;^11,12 however, possess the same drawback of hem-o-lock clips especially in a distended, thickened or friable appendix. In the light of a prospective study, the average size of the base of appendix in acute appendicitis was 12mm (ranging from 6 to 23 mm); the authors suggested use of Hem-o-lock or TC for small diameter and endo-loop or staplers for wider ones. Another factor is slippage of TC reported by Ates et al.¹³ in a patient with repeated abdominal pain following LA. They also reported one patient with IAA and re-exploration with intact stump in TC group.

 In a systematic review, suture ligation was considered superior to other techniques for stump closure.⁴ The suture ligation can be performed with any of these techniques i.e. intra-corporal knotting, needle invagination, commercial endo-loop and manual loop. For the safety and cost effectiveness, Kiudelis M14 stated that intra-corporeal invagination is cheaper than endo-loop but it increases the duration of surgery. Also it requires expertise of intra-corporeal knot tying and the pressure of knot varies from person to person i.e. it may be too tight a knot to cut through the tissues or a loose knot that makes the stump prone to leak.

The manual loop requires a short period of training and its application is smooth and controlled. The knot does not loosen after application and can be applied to any type and size of appendix as shown in our study. It requires an average of 20±1.9 seconds to prepare a knot. One commercial endo-loop costs around 80 USD and applying two loops means 160 USD. On the other hand, one vicryl suture is around 4USD and as many as four loops can be prepared from a single suture. Therefore, manual loop is a safe, reliable and cost effective technique of stump closure5,^15-17 with a negligible rise in operative time i.e. 40 seconds for two loops in our study. Moreover, these manual loops can also be used in other areas i.e. gallbladder, fallopian tube.

Manual loop can be slipped through several instruments i.e. through the fenestrated prongs of Johan forceps,¹⁸ a fascial dilator or laparoscopic metallic knot pusher. We used one fascial dilator in as many as 10 cases after re-sterilization with ETO (Ethylene Oxide) or CIDEX (Activated Glutaraldehyde). One possible reservation would be a theoretical risk of SSI following reuse of a disposable fascial dilator. We observed Superficial SSI in 7.5% patients, which is well within the range reported in a systematic review on appendectomy.¹⁹ However, if a new disposable 14 F fascial dilator is used every time, it would cost 3-5 USD per case; which is still much lower vis-à-vis commercial endoloops.

As the strengths of this study, all the procedures were performed and followed by a single surgeon with a uniform technique and postoperative follow up. The data from June 2014 to May 2016 was collected retrospectively after ERC approval, while the data collection continued till December 2020 to collect a substantial number of cases. The limitation of the study was not having calculated the sample size according to statistical methods. However, a multi-center and effectiveness randomized controlled trial, adequately powered by a priori sample size calculation, having direct comparison of manual loop with commercial endo-loop, and involvement of various surgeons and trainees at different levels is required to reach at an evidence based conclusion and recommendation.

Conclusion

 

In conclusion, the stated facts, figures and logical reasoning corroborate that almost all the methods of stump closure are safe and effective. However, manual loop is additionally cost effective, reproducible, trainee friendly and readily available tool. These qualities encourage a surgeon to adopt it in the day to day practice as well as teach and train without any additional cost of healthcare or risk to the patient.

 

Highlights

 

l Manual loop is safe, cost effective, trainee friendly and reproducible tool to secure appendicular stump in Laparoscopic appendectomy.

It encourages a surgeon to adopt it in the day to day practice as well as teach and train without any additional cost of healthcare or risk to the patient.

Acknowledgements: Dr. Hassaan Khan Niazi & Aniqa Saeed for file review, Ms. Bushra for data entry.

Disclaimer: None

Conflict of Interest: None

Source of Support: None

 

References

 

1.       Eubanks S, Phillip S. L Laparoscopic Appendectomy. In: Fischer JE, editor. Mastery of Surgery. 5 ed: Lippincott Williams & Wilkins; 2007. p. 1607-09.

2.       Vellani Y, Bhatti S, Shamsi G, Parpio Y, Ali TS. Evaluation of laparoscopic appendectomy vs. open appendectomy: a retrospective study at Aga Khan University Hospital, Karachi, Pakistan. J Pak Med Assoc. 2009;59:605-8.

3.       Mayir B, Ensari CO, Bilecik T, Aslaner A, Oruc MT. Methods for closure of appendix stump during laparoscopic appendectomy procedure. Ulus Cerrahi Derg. 2015;31:229-31.

4.       Antoniou SA, Mavridis D, Hajibandeh S, Antoniou GA, Gorter R, Tenhagen M, et al. Optimal stump management in laparoscopic appendectomy: A network meta-analysis by the Minimally Invasive Surgery Synthesis of Interventions and Outcomes Network. Surgery. 2017;162:994-1005.

5.       Yildiz F, Terzi A, Coban S, Zeybek N, Uzunkoy A. The handmade endoloop technique. A simple and cheap technique for laparoscopic appendectomy. Saudi Med J. 2009;30:224-7.

6.       Rakic M, Jukic M, Pogorelic Z, Mrklic I, Klicek R, Druzijanic N, et al. Analysis of endoloops and endostaples for closing the appendiceal stump during laparoscopic appendectomy. Surg Today. 2014;44:1716-22.

7.       Makaram N, Knight SR, Ibrahim A, Patil P, Wilson MSJ. Closure of the appendiceal stump in laparoscopic appendectomy: A systematic review of the literature. Ann Med Surg (Lond). 2020;57:228-35.

8.       Hue CS, Kim JS, Kim KH, Nam SH, Kim KW. The usefulness and safety of Hem-o-lok clips for the closure of appendicular stump during laparoscopic appendectomy. J Korean Surg Soc. 2013;84:27-32.

9.       Varghese G. Feasibility and Efficacy of Using Hem-o-lok Polymeric Clips in Appendicular Stump Closure in Laparoscopic Appendectomy. Cureus. 2018 ;10:e2871.

10.     Lucchi A, Berti P, Grassia M, Siani LM, Gabbianelli C, Garulli G. Laparoscopic appendectomy: Hem-o-lok versus Endoloop in stump closure. Updates Surg. 2017 ;69:61-5.

11.     Strzalka M, Matyja M, Rembiasz K. Comparison of the results of laparoscopic appendectomies with application of different techniques for closure of the appendicular stump. World J Emerg Surg. 2016;11:4.

12.     Gonenc M, Gemici E, Kalayci MU, Karabulut M, Turhan AN, Alis H. Intracorporeal knotting versus metal endoclip application for the closure of the appendiceal stump during laparoscopic appendectomy in uncomplicated appendicitis. J Laparoendosc Adv Surg Tech A. 2012;22:231-5.

13.     Ates M, Dirican A, Ince V, Ara C, Isik B, Yilmaz S. Comparison of intracorporeal knot-tying suture (polyglactin) and titanium endoclips in laparoscopic appendiceal stump closure: a prospective randomized study. Surg Laparosc Endosc Percutan Tech. 2012;22:226-31.

14.     Kiudelis M, Ignatavicius P, Zviniene K, Grizas S. Analysis of intracorporeal knotting with invaginating suture versus J Pak Med Assoc (Suppl. 1) 7th AKU Annual Surgical Conference S-14 endoloops in appendiceal stump closure. Wideochir Inne Tech Maloinwazyjne. 2013;8:69-73.

15.     Mayir B, Bilecik T, Ensari CO, Oruc MT. Laparoscopic appendectomy with hand-made loop. Wideochir Inne Tech Maloinwazyjne. 2014;9:152-6.

16.     Elgendy A, Khirallah MG. Hem-o-lok clip versus hand-made loop in base closure during laparoscopic appendectomy in children. J Pediat Endoscopic Surg. 2019;1:127-32.

17.     Sahm M, Kube R, Schmidt S, Ritter C, Pross M, Lippert H. Current analysis of endoloops in appendiceal stump closure. Surg Endosc. 2011;25:124-9.

18.     Siddique K, Siddiqi N, Sedman P. Use of Johan forceps as endoloop pushers for laparoscopic appendicectomy. Ann R Coll Surg Engl. 2012;94:533-4.

19.     Danwang C, Bigna JJ, Tochie JN, Mbonda A, Mbanga CM, Nzalie RNT, et al. Global incidence of surgical site infection after appendectomy: a systematic review and meta-analysis. BMJ Open. 2020;10:e034266.

20.     Arcovedo R, Barrera H, Reyes HS. Securing the appendiceal stump with the Gea extracorporeal sliding knot during laparoscopic appendectomy is safe and economical. Surg Endosc. 2007;21:1764-7.

Objectives: To determine the frequency of Temporary epicardial pacing wires usage and its predictors in the immediate postoperative period in isolated coronary artery bypass graft surgery.

 

Method: The longitudinal study was conducted at the Aga Khan University Hospital, Karachi, from September 2019 to August 2020, and comprised adult patients of either gender who underwent isolated coronary artery bypass graft in the Department of Cardiothoracic Surgery. Demographic, peri-operative and post-operative Temporary Epicardial Pacing Wires use data was extracted from patient's files and the institutional electronic database. Logistic regression models were built to explore predictors of Temporary epicardial pacing wires usage. Data was analysed using SPSS 22.

 

Results: Of the 322 cases evaluated, 27(8.4%) required the use of Temporary Epicardial Pacing Wires. Mean age of the patients requiring temporary epicardial pacing wires was 66.3±8.9 years compared to 58.7±8.9 years in those who did not require it (p<0.001), while the left ventricular ejection fraction percentage was 44.1±12.8 and 48.9±12.8 respectively (p=0.032). After adjusting for clinically plausible demographics and peri-operative variables, increasing age and low left ventricular ejection fraction were significantly associated with the use of temporary epicardial pacing wires in post-operative period of isolated coronary artery bypass graft patients (p<0.05).

 

Conclusions: The frequency of temporary epicardial pacing wires usage in the post-operative period of coronary artery bypass graft was found to be low.

 

Keywords: Arrhythmias, Adult cardiac surgery, Electrodes, Post-operative, Temporary Epicardial pacing. (JPMA 72: S-16 [Suppl. 1]; 2022) DOI: https://doi.org/10.47391/JPMA.AKU-04

 

Introduction

 

Temporary epicardial pacing wires (TEPWs) are placed routinely during coronary artery bypass graft (CABG) surgery for treating arrhythmias post-operatively.^1,2 They are used peri-operatively to optimise cardiac output by maintaining the rate and rhythm of the heart. Arrhythmias are common post-CABG due to transient damage to  conduction tissue during the operation,^3,4 reported to be 4-58% in isolated CABG patients.⁵ TEPWs are implanted on the right atrium (RA) and/or the right ventricle (RV) of the heart to provide a low resistant pathway between external temporary pacemaker and heart's surface for pacing (Figure).

 

 

 

Most common indication for the use of TEPWs is bradyarrhythmia i.e., heart rate <50/minute, and other indications include atrioventricular (AV) blocks, asystole, junctional tachycardia, ventricular tachycardia, Type-A atrial flutter and atrial fibrillation. TEPWs are  removed prior to discharge by gentle trans-cutaneous traction.⁶

While TEPWs have life-saving advantages, its use also incorporates several risks. Literature has shown the incidence of major complications related to its use to be 0.04-0.4%,^7,8 and these occur during the implantation or removal of the wires or when they are intentionally or unintentionally left inside.⁹ During implantation, they tend to increase both cost and duration of the surgery, additionally having the possibility to cause laceration of the heart chambers, leading to severe haemorrhage.¹ During the removal of these wires there can be major complications, like atrial or ventricular laceration and injury to conduit grafts, leading to cardiac tamponade, which can result in life-threatening situations.⁸ TEPWs, when unable to be removed, are cut flush with the skin, and, hence, a small part of it is intentionally left in the mediastinum that can lead to complications, like mediastinitis, arrhythmias and migration into nearby structures.¹⁰

Post-operatively, frequency of TEPW usage to pace the heart is very low. Bethea et al.¹ reported it to be 8.6%, while Asghar et al. found it to be 2.9%.¹¹ Both these studies identified some characteristics of the patients needing  pacing wires, like increased age, diabetes mellitus, requirement of intra-operative pacing, anti-arrhythmic drugs and history of pre-operative arrhythmias.^1,11 Multiple studies have emphasised on the selective placement of TEPWs in isolated CABG rather than prophylactic placement in all CABGs. Because of its low frequency of usage and its association with major catastrophic complications, the placement of TEPWs in every isolated CABG is controversial. The current study was planned to determine the frequency and associated complications of TEPW usage in the post-operative period of isolated CABG patients, and to explore the predictors of TEPW usage.

 

Patients and Methods

 

The prospective observational study was conducted at the Aga Khan University Hospital (AKUH), Karachi, from September 2019 to August 2020. Since there was no direct interaction with the patients and all records were extracted from their files/electronic database, an exemption from ethical review committee was sought. The sample size was calculated using National Council for the Social Studies (NCSS) Power Analysis and Sample Size (PASS) version 17.0.3.^12,13 To detect a change in R-Squared of 0.31 attributed to at least 10 independent variables using an F-Test, power was kept at 80% and significance level 0.05 to detect an odds ratio of 1.5.^{14The sample was raised using non-probability consecutive sampling technique from among adult male and female patients undergoing either isolated elective or urgent CABG at the AKUH Department of Cardiothoracic Surgery. Those having pre-operative permanent pacemaker in place, undergoing off-pump, emergency or salvage CABG, and patients undergoing CABG in conjunction with some other procedures were excluded.}

CABG was done via full median sternotomy and on cardiopulmonary bypass (CPB). Myocardial protection was achieved with anterograde blood cardioplegia and topical cooling of the heart. On CPB, 34 C systemic cooling was achieved, and mean arterial pressure (MAP) was kept between 70-80mmHg. All patients received RV pacing wire and additional RA pacing wire on surgeon's preference. Post-operatively, patients were kept on ionotropic support as required, which were then weaned off slowly as tolerated.

During the post-operative period, patients were individually evaluated for the need of pacing if they had bradycardia, taken as heart rate (HR) <50/min or asystole causing haemodynamic instability. Duration of pacing was also monitored.

Data was collected prospectively on a predesigned proforma from the patient's file, intra-operative record and electronic database. All subjects were assigned a unique de-identification number. Demographic, clinical and peri-operative variables included age, gender, co-morbidities, like hypertension (HTN), diabetes mellitus (DM), chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), presence of pre-operative arrhythmias, use of anti-arrhythmic medications, ejection fraction (EF) on echocardiography, history of recent myocardial infarction (MI) and presence of left main coronary artery stenosis. During their hospital stay, frequency of therapeutic use of TEPWs was recorded for the type and duration of arrhythmias. Any complications during its placement or removal, length of hospital stay (LOS) of the patients and their post-operative outcomes were also recorded.

Data was analysed using SPSS 22. Mean ± standard deviation (SD) / median along with interquartile range (IQR) were calculated for quantitative variables, such as age, weight, height, body mass index (BMI), EF (%) and LOS (days). Frequencies and percentages were calculated for gender, presence of co-morbidities, history of recent MI, pre-operative arrhythmias, post-operative arrhythmias, in-hospital mortality and pacing requirement. Independent sample t-test was used to assess difference between continuous variables of those who require TEPWs and those who did not. Chi-square test was used to assess significant difference between qualitative variables. Univariate and multivariate logistic regression analysis was performed, and crude and adjusted odds ratios (AORs) were calculated to identify independent predictors of use of TEPWs in patients undergoing isolated CABG. P<0.05 was considered statistically significant.

 

Results

 

Of the 322 cases evaluated, 27(8.4%) required the use of TEPWs. Mean age of the patients requiring temporary epicardial pacing wires was 66.3±8.9 years compared to 58.7±8.9 years in those who did not require it (p<0.001), while the left ventricular EF (LVEF) percentage was 44.1±12.8 and 48.9±12.8 respectively (p=0.032) (Table-1).

 

 

 

Among those who required TEPW post-operatively, 5(18.5%) required pacing in the operating room while coming off cardiopulmonary bypass. The type of pacing mode used in these patients was atrial and AV sequential in 2(40%) each, and ventricular pacing in 1(20%). Besides, 3(11.11%) patients needed a permanent pacemaker due to persistent complete AV block (Table-2).

 

 

After adjusting for clinically plausible demographics and peri-operative variables, increasing age and low EF were estimated as independent predictors of post-operative TEPW (Table-3).

 

 

Discussion

 

The practice of placing TEPWs in isolated CABG is controversial and no consensus yet exists amongst cardiac surgeons for their routine or selective placement. To our knowledge, the current study is one of the few in developing countries, such as Pakistan, to assess the frequency of TEPW usage in the post-operative period of CABG and its predictors. The current results support the selective approach in placing TEPWs in isolated CABG, with the selective groups including patients with advanced age and low pre-operative EF.

The guidelines issued by the American College of Cardiology (ACC), the American Heart Association (AHA) and the Heart Rhythm Society (HRS) in 2018 recommended that the routine placement of TEPWs was reasonable as it has been the standard surgical practice.¹⁵ However, over the recent years there has been a growing number of studies that have examined TEPW use and questioned their routine insertion.^2,11,16 One such study found that routine placement of TEPWs had a negligible role and was associated with increased cost and potential complications.¹¹ Another study found that TEPW implantation is utilised a lot more frequently than needed in cardiac surgery and that it is important to identify independent predictors so that the placement of TEPW can be limited to selected patient populations.¹⁶ The current study also showed that TEPWs should only be placed in high-risk populations.

The patients in the current study had significant medical co-morbidities, making this a diverse sample. The AKUH also has a good cardiac surgery turnover rate, as our one-year prospective study recruited 322 isolated CABG patients of which 85.1% were elective cases and 14.9% were urgent ones. The overall mean age of the patients was 59.3±9.1 years which coincided with data from international studies.¹

In the current study low rate of TEPW usage (8.4%) was found comparable to a study showing a usage rate of 8.6%. Other studies conducted showed as low as 2.9% while one study reported that only 1% of patients required TEPW if predictors for its use were controlled beforehand.¹¹

Interestingly, the current study found increasing age and low pre-operative EF as key independent risk factors for TEPW usage post-operatively after adjusting for multiple covariates. TEPW implantation was likely to increase by 9% with increase in every additional age year and by 5% with decrease in every EF percentage. Both these predictors are reasonable and intuitive, as increasing age is associated with increased risk of multiple co-morbidities that may increase the severity of coronary artery disease, while a low LVEF indicates heart failure and possible cardiomegaly which are all attributable risk of post-operative arrhythmias. The current study did not find any significant association between gender, DM, COPD, CKD, and previous anti-arrhythmic drug which was in line with literature.1,2,16,17

Since the current study was conducted prospectively, there was greater accuracy of data without any missing information. Additionally, the sample size was adequate to run a multivariate regression model to make robust conclusions. However, the findings from this single-centre research might not be generalisable over other populations. The study was also limited in terms of using non-probability consecutive sampling technique.

 

Conclusion

 

There was a low frequency of TEPWs usage post-operatively, and increased age and low EF were found to be significant predictors for its use in isolated CABG patients.

 

Disclaimer: None.

Conflict of Interest: None.

Source of Funding: None.

 

References

 

1.       Bethea BT, Salazar JD, Grega MA, Doty JR, Fitton TP, Alejo DE, et al. Determining the utility of temporary pacing wires after coronary artery bypass surgery. Ann Thorac Surg 2005;79:104-7. doi: 10.1016/j.athoracsur.2004.06.087.

2.       Puskas JD, Sharoni E, Williams WH, Petersen R, Duke P, Guyton RA. Is routine use of temporary epicardial pacing wires necessary after either OPCAB or conventional CABG/CPB? Heart Surg Forum 2003;6:e103-6.

3.       Elmistekawy E. Safety of temporary pacemaker wires. Asian Cardiovasc Thorac Ann 2019; 27:341-6. doi: 10.1177/0218492319833276.

4.       Del Nido P, Goldman BS. Temporary epicardial pacing after open heart surgery: complications and prevention. J Card Surg 1989;4:99-103. doi: 10.1111/j.1540-8191.1989.tb00262.x.

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