Pancreatoduodenectomy (PD) is rarely required in the paediatric population but is the only curative option for certain pathologies such as pancreatoblastoma of the head of the pancreas. Pancreatoblastoma is a rare childhood tumour originating from pancreatic exocrine epithelial cells. It is the most common malignant pancreatic tumour in children.

We describe the case of a 3-year-old girl with Beckwith-Wiedemann (BW) syndrome, with a background of liver resection aged 18 months for hepatoblastoma. On surveillance imaging, a mass lesion was identified in the head of her pancreas, which was further characterised on dedicated MRI pancreas and endoscopic ultrasound. Fine needle aspirate confirmed the diagnosis of pancreatoblastoma. Because of portal and superior mesenteric venous abutment on the initial imaging, a neo-adjuvant approach was taken with good tumour response to cisplatin and doxorubicin, followed by a Whipple's pancreatoduodenectomy (PD).

Using intraoperative video footage, we detail the operative technique of pancreatoduodenectomy in the paediatric population. Modifications to standard reconstruction included a dunking pancreatojejunostomy instead of the more standard Blumgart technique. The patient's background of BW renders a lifelong risk of further solid-organ tumour formation. This case demonstrates how each tumour should be individually assessed with a full MDT approach despite any perceived complexity.

# Guarantor of submission

The corresponding author is the guarantor of submission.

# Introduction

Neoplasms of the pancreas are rare in the paediatric population. In children, a wide variety of pancreatic neoplasms may present.

Beckwith-Wiedemann (BW) syndrome is an overgrowth disorder characterised by congenital features such as macroglossia and macrosomia and a predisposition to tumour formation.

Current treatment for pancreatic neoplasms includes medical and surgical approaches. However, surgical resection is preferred in suitable lesions, allowing for improved long-term survival. Due to the infrequency of presentation and heterogeneity in type, there is no formal guidance on the approach to pancreatoblastoma. Where available, recommendations emphasise the importance of surgical resection [1].

PD is the only surgical approach for tumours of the head and uncinate process of the pancreas. However, it carries with it up to a 32% perioperative complication rate [2]. The objective of this case report is to highlight the intraoperative technique used in paediatric pancreatoduodenectomy.

# Case report

We describe the case of a 3-year-old child with Beckwith Wiederman syndrome, who was found to have an incidental 7 × 6cm mass in the head of her pancreas detected on surveillance imaging, performed in the setting of a prior liver resection for a hepatoblastoma aged 18 months. The mass was in close proximity to the superior mesenteric vein. (Fig. 1
                     . Coronal slice of MRI pancreas demonstrating the tumour at head of pancreas). (Fig. 2
                     . Axial view of MRI pancreas demonstrating tumour indenting SMV).

She received neoadjuvant chemotherapy with doxorubicin and cisplatin with an excellent radiological response. (Fig. 3
                     . Axial view of MRI pancreas pre-chemotherapy). (Fig. 4
                     . Axial view MRI pancreas demonstrating tumour response post chemotherapy).

She then underwent a Whipple's pancreatoduodenectomy. Intraoperative video footage is used in this case report to demonstrate key operative steps to lead to a successful oncological resection. Modifications to the standard Blumgart technique, in this case, included a dunking pancreatojejunostomy, as there was no duct dilatation caused by the tumour. There were no intraoperative complications.

Postoperatively the patient recovered uneventfully, tolerating free fluids on day 2. The amylase content in her drains on day 3 was within normal limits, and these were subsequently removed. She tolerated oral intake on day 4 and was discharged on day 7 post-op.

Pathology showed a low-grade acinar carcinoma, R0 resection with clear margins. Incidental mesenteric lymph nodes analysis was negative.

The patient underwent adjuvant chemotherapy and will undergo lifelong surveillance imaging given the predisposition to tumour formation with BW syndrome. Nutritional support to avoid the longer-term consequences of pancreatoduodenectomy, including pancreatic enzyme replacement therapy, plays a key role in her ongoing management, and she continues to thrive at 18 months post-op.

# Discussion

Although extremely rare, pancreatoblastomas are the most common malignant pancreatic tumours in young children, accounting for 25% of all pancreatic tumours in this age group [3]. Originating from pancreatic epithelial exocrine cells, they usually occur in patients under 10 years of age. Biliary obstruction and accompanying jaundice are uncommon, but α-fetoprotein is often raised. BW syndrome is associated with an increased risk of developing embryonal tumours such as nephroblastomas, hepatoblastomas and pancreatoblastomas. Pancreatoblastoma is a potentially curable malignancy after complete resection alone or following neoadjuvant chemotherapy in high-stage tumours where a microscopically complete resection may be difficult to achieve. The prognosis associated with pancreatoblastoma is closely related to the extent of surgical resection with an overall five-year event-free survival after a complete primary or delayed resection of 75% compared to 28.6% who do not have a complete tumour resection [4].

Pre-operative multimodal imaging plays a crucial role in the diagnosis and assessment of pancreaticoduodenectomies. Abdominal ultrasound in our case demonstrated a large, solitary, well-defined lesion, while multiphase computed tomography with enteral and intravenous contrast shows heterogeneous enhancement and cystic areas within the tumour. Necrotic and hemorrhagic components of the tumour can be seen in T2-weighted parenteral contrast-enhanced magnetic resonance imaging. Pre-operative imaging allows for assessment of visceral and vascular involvement, which may necessitate neoadjuvant treatment and allow for appropriate surgical approach planning. In this case, endoscopic ultrasound with fine-needle aspiration allowed for the obtainment of histology. Squamoid corpuscles on histology are pathognomonic of pancreatoblastoma [5].

PD is the definitive treatment of pancreatic malignancies involving the head of the pancreas. Intraoperative footage is used in this case to demonstrate technical nuances key to a successful oncological clearance during a PD.

An open approach is used as standard practice in the paediatric population and is especially useful in ensuring adequate visualisation of intricate anatomy in younger and smaller patients. As seen in the accompanying intraoperative footage (Supplementary data), after careful adhesiolysis from her previous surgery, the right colon and transverse mesocolon are widely mobilized, followed by a wide Kocher manoeuvre to expose the IVC as far as the left renal vein and aorto-caval groove. After careful adhesiolysis from her previous surgery, the right colon and transverse mesocolon are widely mobilized, followed by a wide Kocher manoeuvre to expose the IVC as far as the left renal vein and aorto-caval groove. We note the bulky tumour, the tumour at the head of the pancreas, the superior mesenteric vein disappearing upwards behind the pancreas. A cholecystectomy is routinely performed, allowing for the subsequent anastomosis of the hepatic duct. The gastroduodenal artery, while the largest branch of the hepatic artery, may be tiny in the Paediatric population. It is identified, divided and oversewn after ensuring antegrade flow in the common hepatic artery. To mobilise the pancreatic neck, we further dissect the hepatoduodenal ligament and identify the portal vein, then turn our attention to the inferior border of the pancreas in order to identify the SMV. This is facilitated by following the middle colic and gastroepiploic veins identified previously on side mobilization of the right colon and duodenum. We then create a retropancreatic tunnel at this level, and mark it with nylon tape.

With the stomach retracted, the surgeon uses cautery to divide the head of the pancreas to the left of the nylon tape. We then identify the ligament of Treitz and the root of the mesentery and divide the jejunum using a stapler at the second jejunal arcade. The mesenteric venous system is then displayed by rolling the pancreatic head off the large portal vein with blunt dissection. The surgeon must then sharply dissect the uncinate process off the SMA using traction of the specimen to pull the SMA into clear sight. It is persistently palpated for pulsation to avoid injury, and any inferior pancreaticoduodenal branches are dealt with using ligatures. The stomach is divided (pre-pyloric) using an endo-GIA stapler. The specimen is removed en bloc, achieving complete oncological clearance and leaving the specimen bed in view for reconstruction.

The hepaticojejunostomy is created using 6-0 PDS downstream from the pancreatojejunostomy using an end to side anastomosis in an interrupted fashion. The pancreatojejunostomy will be created in 2 layers with 6–0 PDS and enveloping the pancreas into the jejunum in an end to side anastomosis. This was appropriate in this case as the pancreatic remnant was of appropriate size for the dunking technique, and the tumour did not cause duct dilatation, and therefore the duct was not identifiable. Finally, we create an ante colic gastrojejunostomy 40 cm distal to the hepaticojejunostomy using 4-0 PDS in two layers in an end to side fashion. 2 drains are left in close proximity to the biliary and pancreatic anastomosis. As we move through each of the traditional adult PD steps, we appreciate the application of skills and techniques from modern-day HPB/Pancreatic adult surgical practice to the paediatric population.

The combined HPB and paediatric surgery expertise led to a successful outcome in this case. A pancreatic leak is potentially the most serious short-term postoperative complication, occurring in 14% of paediatric patients. 42% develop long-term postoperative complications, with ‘pancreatic insufficiency occurring in 32% and delayed gastric emptying in 9%. There is a lack of data available to guide surgeons on the optimum approach to managing pancreatoblastomas in children, with recommendations based on small retrospective case studies. This is especially true when performing PD in a child with prior malignancies and with the potential need for mesenteric vascular resection, both of which were considerations in our case [2]. A neo-adjuvant approach was crucial in avoiding the need for vascular resection, allowing a determination of the biology and chemo-sensitivity of this particular tumour, and allowing time for the multidisciplinary services, including dietetics and oncology support, to engage with and educate the child and her family.

As described by Büchler and colleagues, with advances in surgical management and systemic therapy, the importance of surgical techniques in resectable pancreatic cancer is expected to increase. Recent advances in adult HPB surgery, such as minimally invasive approaches and the TRIANGLE procedure (aiming to resect all of the meso-pancreas along clearly defined vascular margins), look to improve outcomes. Evidence-based advances can be applied to the paediatric cohort in a similar fashion, but further research is needed [6].

This case underlines the importance of joint decision-making and the involvement of the multidisciplinary team. The lack of high-quality data on the management of pancreatoblastoma, the nature of the intervention, and the potential for procedural and malignancy-related poor outcomes can make it difficult to counsel patients and their caregivers. Families must be comprehensively educated on the possible management options and their implications by the entire MDT. Families can then make an informed decision that considers their personal beliefs and expectations.

# Conclusion

In summary, given the patient's background of BW syndrome, there will always be a likelihood of further solid-organ tumour formation. This case demonstrates how each tumour should be individually assessed with a full MDT approach despite any perceived complexity. Evidence this far has shown survival outcomes in the paediatric population undergoing PD for pancreatoblastoma are intrinsically linked to complete oncological resection [7]. Given the rarity of pancreatoblastoma and indeed a paediatric PD, we aim to share our intraoperative footage and clinical details.

Finally, the collaborative approach between the paediatric surgical and ancillary services and the surgeon with adult hepatobiliary expertise was key to the successful outcome in this case. The expertise needed for paediatric HPB surgery is highly specific and, in general nowadays, requires an adult HPB/Transplant surgeon with specialty interest training in paediatric surgery, such that the skillset of more focused adult surgeons can be matched within the paediatric unit for the benefit of the child and the population at large.

# Submission declaration and verification

This case report has not been previously published. It was presented at the 14th Biennial Congress of the European-African Hepato-Pacreato-Biliary Association, in Bilbao, Spain on 15–17 September 2021.

# Authorship

All authors attest that they meet the current ICMJE criteria for Authorship.

# Informed consent

The patients parent's consent was obtained for the publication of this case report and intraoperative footage.