Minimal access surgery in newborns and small infants; five years experience.

AIMS AND
OBJECTIVES: The aim of this study was to assess and present the outcome (initial experience and lessons learnt) of minimally invasive surgery for various indications in neonates and small infants (< 5 kg) at a single medical centre.
MATERIALS AND METHODS: A retrospective analysis was performed on 65 patients (age day 2 to 10 months) managed with minimal access surgery (MAS) for various indications, between 2005 and 2010. We analyzed demographic information, procedures, complications, outcomes, and follow-up and overall feasibility of the procedure.
RESULTS: No serious complications except one death in congenital diaphragmatic hernia (CDH) (due to other comorbidities) occurred. Intra operative hypercarbia and hypoxia were observed more frequently in thoracoscopic procedures. Intra operative hypothermia was not common and was well tolerated. Conversion to open procedure (n = 5), post operative ileus (n = 3), port site infection (n = 5) were other complications.
CONCLUSION: MAS in neonates and small infants is a technically demanding but a feasible choice available. Some prior experience in older children is required for safe and effective outcome. Good quality optics, video equipments and instruments are required for safe and effective procedure. Intra operative measurement of oxygen saturation and temperature, and diligent post operative ICU care are mandatory for safe and successful outcome.

INTRODUCTION

The past decade has witnessed exponential growth of ‘Minimal Access Surgery’ (MAS) in paediatric age group. Virtually every abdominal and thoracic surgery has been performed or attempted using minimal access approach in children. Though the first true neonatal laparoscopy was described in 1973 by Gans and Berci,[1] MAS in neonates and young infants has lagged behind because of presumed technical challenges and/or unacceptably high risk in this subgroup.[2] However, as the skills of paediatric surgeon improved, coupled with improved optics, video technology, new generation energy sources and refined miniature instruments specifically designed for such babies, MAS in this group is gaining momentum.[3-5]

MATERIALS AND METHODS

We did a retrospective analysis of all the paediatric patients, weighing less than 5 kg, who underwent minimal access surgeries in Department of Paediatric Surgery in a tertiary care institute in Mumbai, India from June 2005 to June 2010. A total of 65 cases were identified. There were no exclusions.

From 2005 to 2008, procedures were performed using 5 mm telescope (0° and 30°) and 5 mm instruments. After 2008, surgeries were performed using smaller instruments like 2.7 mm telescope or 3 mm hand instruments. All surgeries were performed with basic instruments; Maryland dissector, hook, atraumatic grasper, bipolar cautery forceps, needle driver and endoscopic scissors, with occasional use of Harmonic Scalpel (Ethicon Endosurgery, Cincinnati, USA). Procedures were performed using single chip camera during 2005–2008, in 2009 using 3 chip camera and in 2010 using high definition (HD) camera. Laparoscopic surgeries were performed in supine, semi lateral and sometimes with added lithotomy position. Primary port was inserted with open technique either in epigastrium or sub umbilically. CO2 insufflation was used in all cases with pressures ranging from 8 to 12 mmHg and flow rates of 1–3 l/min.

The techniques of inguinal hernia repair,[6] mediastinal cyst excision,[7] liver cyst deroofing,[8] ovarian cyst[910] have already been described. Pyloromyotomy [Figure 1], excision of duplication cyst, anorectal pull-through and diagnostic laparoscopy were done using 3 ports. Hiatus hernia repair and myotomy for achalasia cardia were done with 4 ports and Morgagni hernia repair [Figure 2] was done with 3 ports using extracorporeal knot technique. Thoracoscopic surgeries were performed predominantly in lateral position (modified prone lateral or supine lateral in few cases, depending upon the site of pathology) using 2 or 3 ports. Lung collapse was obtained with CO2 insufflation at pressures of 4–6 mm of Hg. A low flow, low pressure CO2 insufflation was used throughout the procedure in all cases to keep the lung collapsed. An inter-costal drain (ICD) was inserted through the lowest port in all cases. Thoracoscopic repair of congenital diaphragmatic hernia (CDH) were done with 3 ports with either intra corporeal or extra corporeal knotting along with use of pericostal rib anchoring sutures when needed. Thoracoscopic repair of CDH was performed selectively in babies who were not on ventilator support pre-operatively, except the first case.

Figure 1

(a) The ‘Olive’ of hypertrophied pylorus, (b) and (c) Separation of incised muscle fibres, (d) Completed myotomy

Figure 2

(a) X–ray of chest showing Morgagni hernia. (b) Laparoscopic view of Morgagni hernia with herniated bowel loops. Black arrow indicates rim of the defect and white arrow indicates falciform ligament. (c) Hernia defect after reduction of contents. Left lobe of liver is retracted downwards (black arrow). (d) Closed defect with Prolene 2.0

All patients were monitored by skin temperature, electrocardiogram, trans cutaneous pulse oxymeter, end tidal CO2 and non invasive blood pressure monitor during and after surgery in surgical intensive care unit (ICU). Patients were followed up for 3 months to 2 years.

RESULTS

A total of 65 procedures were performed over a period of 5 years. Fourteen different procedures were performed. There were 50 laparoscopic and 15 thoracoscopic procedures [Tables 1 and 2]. Mean age was 2.3 months. Mean weight was 4.3 kg. There were five preterm babies.

Table 1

Laparoscopic Procedures (n = 50)

Table 2

Thoracoscopic Procedures (n = 15)

LAPAROSCOPIC PROCEDURES

Inguinal hernia repair was performed with intra corporeal knotting (n = 15) and extra corporeal knotting (n = 7) as per surgeon's preference [Figure 3]. Mean operative time was 40 min for unilateral and 55 min for bilateral hernia. Contralateral patent processus vaginalis was found in one female and in five males. One patient had Meckel's diverticulum and was managed during the same surgery. One patient developed fall in oxygen saturation during surgery. Two patients developed post operative hypothermia and one developed transient apnea in immediate post operative period. Feeds were started on next day of surgery for first 15 cases and on the day of surgery in last 7 cases. One patient had hydrocele formation on follow up, which resolved by 3 months without any intervention. One patient developed high testis, which required open orchidopexy at 1 year of age. No recurrence, testicular atrophy or metachronous hernia was found on follow up.

Figure 3

(a) Open right side deep inguinal ring (black arrow) in a 5 weeks old male infant. Note the limited amount of working space available. (b) Close up of open right side deep inguinal ring showing the anatomical landmarks; vas deferens (black arrow) and testicular vessels (red arrow). (c) Purse string closure of deep ring with intra-corporeal knot

Three nephrectomies were for non functioning dysplastic kidney with grade V reflux and recurrent urinary tract infections (UTI) in patients of posterior urethral valve. One nephrectomy was performed for large multi cystic dysplastic kidney. One patient required conversion due to technical problems. All specimens were delivered through one of the ports after widening the port. Mean operative time was 55 min. One patient developed post operative ileus and took 3 days to resolve. In all other cases feeds were started on the next day and patients were discharged after 2 days.

Out of 8 ovarian cysts, 6 were prenatally diagnosed. All ovaries were preserved since all cysts were benign. Cysts were excised [Figure 4] (n = 5) or deroofed (n = 3). Specimens were delivered through one of the ports. In 2 cases, we used only 2 ports, the cyst deroofed extracorporeally. One patient developed post operative ileus and one developed port site infection.

Figure 4

(a) Huge ovarian cyst being aspirated in a neonate. (b) Near total excision of ovarian cyst. Black arrow indicates fallopian tube

Both procedures for anorectal malformation required conversion due to technical reasons. Both duplication cysts were excised after aspiration with average time of 45 min. One developed post operative port site infection. Indications for diagnostic laparoscopy were disorders of sexual differentiation (n = 2) and umbilical pathology (n = 1) and presacral cystic mass extending in pelvis (n = 1). Myotomy for achalasia cardia was converted to open procedure because of oesophageal mucosal breach.

THORACOSCOPIC PROCEDURES

Thoracoscopic CDH repairs was performed in 10 patients (6 newborns and 4 infants) [Figure 5]. There was one conversion. Mean duration of CDH repair was 110 min (range 70-160 min). Neonates developed hypothermia during CDH repair when duration of surgery was longer than 2 hours, however, it was well tolerated. Overall 50% of patients developed fall in oxygen saturation and rise in end tidal CO2 which was managed by increasing minute ventilation, reducing CO2 insufflation pressure and flow rate and by increasing muscle relaxation. Post operatively, 5 neonates and 2 infants were managed with conventional mechanical ventilator support for an average of 3.3 days (range 2-5 days). ICD was removed once patient was off ventilator and feeds were started when bowel function returned (average 5 days). Three patients did not require post operative ventilator support and feeds were started by 2nd post operative day except in one case, where post operative ileus was prolonged and feeds were started on 6th post operative day. Difficulty in reduction of hernia contents warranted the conversion in a neonate with a right side CDH. One newborn died post operatively, because of complex cardiac anomalies and severe pulmonary hypertension. One infant developed recurrence within 1 month which was repaired by laparotomy.

Figure 5

(a) Herniated spleen and bowel loops in left hemithorax through the left side congenital diaphragmatic hernia (CDH). (b) Spleen being pushed through the postero-lateral defect in to abdominal cavity. (c) Repair of the defect in progress. (D) Completed repair with Ethibond 2.0

Indication for video assisted thoracoscopic surgery (VATS) decortication was incomplete resolution of empyema with initial inter costal drainage. Total duration of symptoms was less than 2 weeks before VATS decortication. All but one had undergone contrast enhanced computerised tomography (CT) scan of chest. All required blood transfusion. Average duration of surgery was 75 min (range, 55–110 min). ICD was kept for 4–5 days post operatively. Feeds were started on the next day of surgery. One patient developed hypothermia and transient apneic spell in post operative period but could be managed without ventilator support. Two patients developed port site infection which subsided within a week with topical antibiotic and dressings.

Five procedures (7.6%) were converted to open procedures due to technical difficulties. The intraoperative and postoperative complications are shown in Table 3.

Table 3

Complications

During follow up functional and cosmetic results were excellent.

DISCUSSION

Safety and efficacy of MAS in neonates and small infants has been proved by several studies.[3-51112] However, concerns regarding safety, efficacy and complications have been raised.[451314] The concerns were two fold:

The deleterious effects of CO2 insufflation, CO2 absorption, pneumoperitoneum, pneumothorax and single lung ventilation on the immature physiology of such small babies. This subgroup of children is particularly sensitive to effects of CO2 insufflation and absorption, namely respiratory acidosis, hypercapnia, hypothermia and fall in blood pressure.[4515-19]

Small working space, technology and suitable equipment for surgery.[2-513]

Evolutions in anaesthesia techniques, anaesthetic agents and experienced paediatric anaesthesiologists have addressed the primary concern of CO2 insufflation.[2-5] We experienced hypothermia, desaturation episodes and hypercapnia in less than 10% cases which is comparable to 12% reported by Kalfa et al.[4] None of the episodes warranted a conversion. Post operative hypothermia and transient apnea developed in three babies, out of which two were pre terms. Since blood chemistry was found normal afterwards, we attributed the transient apnea episodes to hyothermia. This finding underscores the need for diligent monitoring in ICU for first few hours after surgery.

Conventional inguinal herniotomy in such small babies is a technically demanding procedure[20] and is associated with an increased risk of incarceration,[2122] an increased risk of recurrence[23] and testicular atrophy.[24] We did not find any recurrence or testicular atrophy in our series and we agree with Schier[25] that probably laparoscopic hernia repair in this subgroup is a better choice. We and Nagraj et al.[20] both found cases of high testis which required orchidopexy. It is not clear whether it is a complication of surgery or acquired ascent and it necessitates further study.

Laparoscopy for neonatal ovarian cyst allows complete exploration of peritoneal cavity, confirmation of the diagnosis and its management, and inspection and management of contra lateral ovary.[26]

We do not consider conversions as complications or failures and we agree to the argument of “nothing lost” in attempting laparoscopy first as long as the procedure stays safe and reasonable.[3] Both conversions in anorectal malformation were because of poor visibility due to dense adhesions in colostomised patients. Patient of achalasia cardia underwent dilatation prior to surgery, and this fact may have some bearing on difficulties we encountered and subsequent conversion.

Our technique of CDH repair evolved over time with our experience. The initial bitter experience of a death of a neonate, who was on ventilator support pre operatively, stopped us doing CDH repair thoracoscopically in babies who were on ventilator support. We experienced one recurrence which was our second case. We attribute the recurrence to excessive tension and not taking a pericostal suture where it was required. We started with silk then nylon and poly propylene. Currently we are using polyester and extra corporeal knot technique. In our experience extra corporeal knotting reduces duration of surgery and ensures knot security. Though no formal comparison of laparoscopic and thoracoscopic approach have been made so far, thoracoscopy offers advantages in terms of space and easy reduction, however, it cannot assess malrotation and other abdominal pathologies.[27-29] We experienced similar benefits; however, the reduction of contents in a hernia without a sac was at times prolonged and difficult. Management of stage II empyema is a complex and a highly debated issue.[30] We follow the practice of primary inter costal tube drainage (without fibrinolytics) and if required VATS drainage and decortication in infants. The outcome was satisfactory in all cases with minimal morbidity and shorter post operative stay. The perceived advantages of MAS are minimum scars, less pain, early recovery and reduced chances of post operative adhesions and subsequent adhesive obstruction.[315] We encountered three cases of prolonged ileus in post operative period which were managed conservatively. This fact perhaps suggests a need of long-term follow up to prove benefits of laparoscopy in reducing adhesive intestinal obstruction.

We also agree to the fact that there is a significant learning curve for MAS in this sub group of children.[31] We have witnessed the phenomenon of learning curve throughout our journey of paediatric MAS. Prior to embarking on procedures in such small children we performed procedures in bigger children and acquired the necessary skills and confidence. Neonatal MAS requires small light weight instruments and excellent image quality for safe and effective outcome[32] and we felt the same way after acquiring smaller scopes, shorter instruments and high definition video equipments. We agree with Rothenberg[31] that it requires true commitment from the surgeon and his team and it is worth to avoid a big scar and its outcome.

CONCLUSION

MAS in neonates and small infants is feasible and safe. Recent advances in technology have widened the spectrum of procedures that can be performed. Experienced team of surgeons and anaesthesiologist is mandatory for safe outcome as is post operative monitoring. With rapidly evolving technology the possibilities are endless and perhaps the only limiting factor would be the experience and skill of the surgeon.