Are Cardiac Anomalies and Persistent Fetal Circulation a Risk Factor for Cardiovascular Events During Minimally Invasive Surgery in Neonates?

Abstract

Introduction:

Minimally invasive surgery (MIS) in neonates is progressively performed. The aim of this study was to evaluate the risk for cardiovascular events during endoscopic surgery in neonates and to analyze the influence of persistent fetal circulation and/or cardiac anomalies.

Materials and Methods:

This is a retrospective single institution study including all neonates undergoing MIS. The charts were reviewed for intraoperative cardiovascular events and operative procedure was performed. Special attention was paid to cardiac anomalies and persistent fetal circulation. In addition, a review of the literature was performed.

Results:

Between January 2004 and December 2012, 108 neonates underwent MIS at our institution. Laparoscopic surgery was performed in 91 (84.3%) and thoracoscopy in 17 (15.7%) babies. None of these 108 patients developed a cardiovascular event during endoscopic surgery (0.0%). Persistent fetal circulation and/or cardiac anomalies were evaluated in 50 of 108 (46.3%) neonates. In the additionally performed review of the literature, four single case reports were identified. All 4 authors published a major cardiovascular event during laparoscopic surgery in neonates. In all 4 patients, gas embolism through a patent umbilical vein was assumed to be responsible for the cardiovascular event.

Conclusions:

In our opinion, the main risk factor for the development of a major cardiovascular event during MIS in neonates is vascular injury of a persistent umbilical vein. Persistent fetal circulation and/or cardiac anomalies seem to be less important. In case of injury of a persistent umbilical vein, the risk of gas embolism has to be respected and conversion to the open approach has to be considered.

Introduction

Minimally invasive surgery (MIS) is progressively performed in pediatric surgery. Nevertheless, physiological characteristics of neonates put this special group of patients at higher risk for intraoperative complications. Until today, there is a lack of knowledge concerning the impact of MIS and the physiological induced response of the neonate. Especially the feto-to-neonatal adaption of the cardiovascular system could be an important factor in the performance of MIS.¹ However, in the past decades, the advantages of endoscopic techniques for a wide range of indications have been proven, even for small infants and neonates.¹ Notably, there are also a few reports on the successful performance of endoscopic surgery in infants and neonates with cardiac anomalies and persistent fetal circulation.^2–5 Undisputably, the most severe intraoperative complications during MIS in neonates are cardiovascular events. Until today, it is unknown whether neonates with cardiac anomalies and/or persistent fetal circulation are at higher intraoperative risk. However, during the first month of life, several congenital anomalies require surgical correction. The aim of this study was to evaluate the risk of cardiovascular events during endoscopic surgery in neonates and to analyze the influence of persistent fetal circulation and/or cardiac anomalies in this exceptional period of life.

Materials and Methods

In this retrospective single institution study, all term and preterm neonates undergoing MIS within the first month of life were included. Prematurity was defined as <37 weeks of gestational age at birth. The charts were reviewed for intraoperative major cardiovascular events, performed operative procedure, and conversion rate. Special attention was paid to cardiac anomalies and persistent fetal circulation. In addition, a review of the current literature concerning reported cardiovascular events during MIS in neonates was performed. A literature search was done on all articles published on reported cardiovascular events during laparoscopic surgery in term and preterm neonates.

Operative procedures

All neonates underwent surgery at the operating room using general anesthesia and tracheal intubation. In all performed laparoscopic procedures, the patients were placed in supine position and a capnoperitoneum was created using a Veress needle inserted at the umbilicus. Carbon dioxide (CO₂) insufflation was started with intra-abdominal pressures between 8 and 12 mmHg (average 10 mmHg). The Veress needle was exchanged for a trocar and a laparoscope was inserted. The procedure was continued according to the performed laparoscopic procedure and additional trocars were placed in the abdomen.

In all performed thoracoscopic procedures, the thorax was accessed with a miniport, and insufflation with CO₂ was started to bring about lung collapse. Intraoperative insufflation pressure varied from 8 to 15 mmHg (average 9 mmHg). Depending on the performed procedure, two to four additional trocars were placed.

Results

Altogether 108 neonates (62 male and 46 female babies) were identified. Between January 2004 and December 2012, 72 term (66.7%) and 36 preterm (33.3%) patients underwent endoscopic surgery within the first month of life. Median gestational age at birth was 37 weeks with a range of 25 to 42 weeks. Median birth weight was 2.9 kg with a range of 1.2 to 4.1 kg. On average, the minimally invasive procedure was performed on the 12th postnatal day (range 0 to 30 days). Median weight at the time of surgery was 3.0 kg with a range from 1.2 to 4.0 kg. Laparoscopic surgery was performed in 91 (84.3%) neonates (59 term and 32 preterm). Seventeen babies (15.7%) underwent thoracoscopy (13 term and 4 preterm). Conversion to open surgery was necessary in 21 patients (19.4%) due to poor visualization or intraoperative findings leading to the necessity to proceed with open surgery. In our series, none of the 108 term and preterm babies (0.0%) undergoing MIS within the first month of life developed a major cardiovascular event during the surgical procedure. Persistent fetal circulation and/or cardiac anomalies were evaluated in 50 of 108 (46.3%) neonates undergoing endoscopic surgery within the first month of life. Thirty-four term and 16 preterm neonates were identified with different cardiac anomalies and/or persistent fetal circulation. Patent foramen ovale (PFO) (n = 34) and persistent ductus arteriosus (PDA) (n = 21) were most common. Combinations of cardiac anomalies and persistent fetal circulation were identified in 26 neonates undergoing MIS within the first month of life. Table 1 presents the incidence of cardiac anomalies and persistent fetal circulation.

Table 1.

Types and Frequencies of Cardiac Anomalies in Neonates Undergoing Laparoscopic or Thoracoscopic Surgery Within the First Month of Life

	Total no.
PFO	n = 34
PDA	n = 21
ASD	n = 10
VSD	n = 6
Tricuspide valve insufficiency	n = 4
Tetralogy of Fallot	n = 2
Pulmonary valve insufficiency	n = 2
Mitral valve insufficiency	n = 2

ASD, atrium septal defect; PDA, persistent ductus arteriosus; PFO, patent foramen ovale; VSD, ventricular septal defect.

Operative procedures

The most frequently performed laparoscopic procedure in neonates was laparoscopic inguinal hernia repair (n = 36). In 23 neonates, laparoscopic duodenoduodenostomy was performed due to different intrinsic or extrinsic reasons of duodenal stenosis. Laparoscopic pyloromyotomy was performed in 7 neonates. Thoracoscopic repair of esophageal atresia was performed in 12 neonates and thoracoscopic repair of congenital diaphragmatic hernia in 5 infants. Table 2 demonstrates the performed endoscopic procedures in term and preterm neonates undergoing MIS within the first month of life.

Table 2.

Performed Laparoscopic and Thoracoscopic Procedures in Neonates Within the First Month of Life

	Total no.
Laparoscopic hernia repair	n = 36
Laparoscopic repair of duodenal atresia, stenosis, or duplication	n = 23
Laparoscopic-assisted resection of intestinal atresia or duplication	n = 12
Laparoscopic pyloromyotomy	n = 7
Laparoscopic correction of acute volvulus or malrotation	n = 5
Diagnostic laparoscopy or other laparoscopic procedures	n = 6
Laparoscopic repair of CDH	n = 2
Thoracoscopic repair of EA	n = 12
Thoracoscopic repair of CDH	n = 5

CDH, congenital diaphragmatic hernia; EA, esophageal atresia.

The systematic review of the literature identified four single case reports presenting major cardiovascular events during MIS in term and preterm neonates.^6–9 Two babies were supposed to undergo laparoscopic repair of duodenal atresia and 2 babies for laparoscopic pyloromyotomy. Age at the time of MIS in these 4 neonates varied from 1, 3, 12 days to 3 weeks. All 4 neonates developed a major cardiovascular event at the onset (n = 3) or before (n = 1) the onset of peritoneal insufflation. In 2 of the babies, a bleeding of the umbilical vein was reported.^6,7 In 1 patient, initial insufflation was unsuccessful and a Hasson port was introduced under direct vision.⁸ All neonates required cardiopulmonary resuscitation (CPR) due to pulseless electrical activity,^6,8 cardiac arrest,⁷ or decline in systolic blood pressure and heart rate.⁹ In all of the neonates, gas embolism through a patent umbilical vein was assumed to be responsible for the cardiovascular events.^6–9 In 2 cases, intraoperative echocardiogram detected gas embolism^6,7 and in 2 cases, intraoperative X-ray showed gas embolism.^8,9 In 1 of these 4 patients, preoperative echocardiogram showed a small PDA with left-to-right shunt and a PFO.⁸ In 1 baby, intraoperative echocardiogram showed a PDA with left-to-right shunt,⁶ and in the other baby, a PFO was detected.⁷ In these 2 cases, no preoperative echocardiograms were reported. In the fourth neonate, postoperative echocardiogram was normal and no preoperative echocardiogram was mentioned. Intraoperatively, gas embolism was confirmed using X-ray.⁹ The applied peritoneal pressure was only specified in one of these patients.⁹ In this case, the applied insufflation pressure was 6 mmHg. All neonates were successfully resuscitated. In one of the neonates, conversion to open surgery was performed immediately after resuscitation,⁷ in the other 3 cases, reoperation was performed a few days later using the open approach.^6,8,9 Table 3 shows a comparison of the four identified case reports concerning supposed cause of cardiac arrest, intraoperative insufflation pressure, reported cardiac anomalies, and/or fetal circulation and time to performance of open surgery after initial CPR. Fortunately, all 4 neonates were reported to show no signs of neurological or cardiovascular sequelae at discharge.^6–9

Table 3.

Comparison of Supposed Cause of Cardiac Arrest, Intraoperative Insufflation Pressure, Reported Cardiac Anomalies and Fetal Circulation in Echocardiogram, and Performance of Open Surgery After Initial Cardiopulmonary Resuscitation in Four Identified Case Reports

	Supposed cause of cardiac arrest	Intraoperative insufflation pressure	Cardiac anomalies and/or fetal circulation in echocardiogram	Performance of open surgery after initial CPR (days)
Lalwani and Aliason	Air embolism	Not reported	Postoperative PDA	2
Taylor and Hoffman	Air embolism	Not reported	Intraoperative PFO	0
Olsen et al.	Air embolism	Not reported	Preoperative PDA and PFO	12
Kudsi et al.	Carbon dioxide embolism	6 mmHg	Postoperative no cardiac anomalies and fetal circulation	7

CPR, cardiopulmonary resuscitation; PDA, persistent ductus arteriosus; PFO, patent foramen ovale.

Discussion

Cardiovascular events are the most severe intraoperative events during surgery. Until today there is a lack of knowledge concerning the impact of persistent fetal circulation and/or cardiac anomalies for the development of major cardiovascular events during endoscopic surgery in neonates. In term and preterm infants, persistent fetal circulation and/or cardiac anomalies are frequent. In addition, during the first weeks of life, the foramen ovale and ductus arteriosus are only functionally and not anatomically closed in babies without persistent fetal circulation in the echocardiogram. General recommendations for the use of MIS in neonates with persistent fetal circulation and/or cardiac anomalies are still lacking. However, reduced postoperative pain, faster recovery, and improved cosmetic results are the main advantages of the minimally invasive approach. In the literature, there are several promising reports on successful MIS in infants and neonates with cardiac anomalies and persistent fetal circulation.^2–5 This study aimed to analyze our personal experiences with endoscopic surgery in neonates and to review the literature for reported cardiovascular complications during laparoscopic and thoracoscopic surgery. In our personal series, none of the 108 neonates (0.0%) developed a major cardiovascular event during laparoscopic and thoracoscopic surgery. Almost half of the patients were known to have cardiac anomalies and/or persistent fetal circulation preoperatively.

In the review of the current literature, four single case reports on major cardiovascular events in neonates were identified. All 4 patients underwent laparoscopic surgery, none of them thoracoscopic surgery. In all babies, gas embolism through a patent umbilical vein was assumed to be responsible for the major cardiovascular event requiring CPR. In 3 cases, the authors presumed an air embolism,^6–8 whereas 1 author hypothesized a CO₂ embolism.⁹ Interestingly, in 1 neonate, abdominal insufflation was not even started at the time of gas embolism. In the other 3 babies, the decrease of end-tidal CO₂ with drop of blood pressure and heart rate occurred shortly after abdominal insufflation was started. Injury of a patent umbilical vein was supposed to be the entrainment of gas in all four case reports.^6–9 Theoretically, CO₂ is, in contrast to air, rapidly cleared from the circulation due to its high solubility in blood because of its binding and buffering.^7,8

Concerning cardiac anomalies and persistent fetal circulation, a preoperative echocardiogram was reported in only 1 of the 4 neonates. This patient had a small PFO with shunting and a PDA. The other 3 authors did not mention a preoperative echocardiogram. Intra- or postoperative echocardiogram showed a PFO, PDA, or both in three of four identified case reports. However, it is unclear whether this was a reaction to gas embolism or already existing preoperatively. Only 1 of the 4 neonates had a normal echocardiogram postoperatively without evidence of cardiac anomalies or persistent fetal circulation. In this baby, gas embolism was verified intraoperatively using X-ray; a preoperative echocardiogram was not reported.⁹

Gas (CO₂ or air) embolism is a rare but serious complication of laparoscopic surgery in neonates. The presence of an open umbilical vein and persistent fetal circulation are the most important risk factors for the development of gas embolism. Olsen et al. stated in their case report that the neonate is particularly vulnerable to gas embolism due to a PFO and PDA.⁸ They predicate that creation of a pneumoperitoneum for laparoscopic surgery in the first 2 to 3 weeks of life may confer an increased risk for gas embolism.⁸ Kudsi et al. state that the incidence of gas embolism may be lower when peritoneal insufflation is performed using an open technique rather than a Veress needle.⁹ Misplacement of the Veress needle into a vein or parenchymal organ is the leading cause of CO₂ embolism.⁹ Therefore, the authors recommend using the open technique with careful dissection and an intra-abdominal pressure of 8 to 10 mmHg.⁹ The applied insufflation pressure was 6 mmHg in the case of Kudsi et al.⁹ The other authors did not mention their insufflation adjustments.^6–8 Taylor and Hoffman state that the risk of the umbilical approach in neonates is greater than in older patients who lack residual fetal vessels that may permit right-to-left shunting and paradoxical emboli.⁷ In their opinion, the greatest risk of air embolism exists for the smallest patients shortly after initial insufflation.⁷

Conclusions

In our personal series, none of 108 neonates undergoing endoscopic surgery within the first month of life developed a major cardiovascular event intraoperatively. Almost half of the babies were known to have cardiac anomalies and/or fetal circulation. In the review of the current literature, four single case reports were identified reporting on gas embolism during laparoscopy. All authors hypothesized that air or CO₂ embolism through injury of a patent umbilical vein was responsible for the major cardiovascular event requiring CPR. Pre-existing cardiac anomalies and persistent fetal circulation were insufficiently reviewed. In our opinion, the main risk factor for the development of a major cardiovascular event during laparoscopic surgery in neonates is vascular injury of a persistent umbilical vein. Cardiac anomalies and/or persistent fetal circulation in neonates seem to be of minor importance. Consequently, careful preparation of the umbilical region is most important to prevent the onset of gas embolism during laparoscopic surgery in neonates with or without cardiac anomalies and/or persistent fetal circulation. In case of injury of a persistent umbilical vein, conversion to open surgery has to be respected to prevent a major cardiovascular event due to gas embolism in this special group of patients.

Footnotes

Disclosure Statement

No competing financial interests exist.

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