A standardised and reproducible method for en bloc multi-visceral organ retrieval in a porcine model – Barnett

Introduction

Background

The removal of a composite block consisting of multiple abdominal organs retrieved together is a challenging procedure but offers transplantation researchers the opportunity to advance understanding of both multi-visceral transplantation (MVT) as well as ex vivo preservation and resuscitation. MVT is typically reserved as a final therapeutic option for the most severe manifestations of various gastrointestinal and hepatobiliary diseases that would otherwise result in mortality (1,2). Indications for the procedure are expanding to include carefully selected patients with malignancies, in addition to those with benign conditions (3,4). While the term MVT can be used to refer to the transplantation of any two organs into a single recipient, as a distinct entity, it generally refers to a subset of intestinal transplantation. Although definitions vary in the literature, MVT typically involves the transplantation of the stomach, duodenum, liver, pancreas, small intestine, and colon up to the splenic flexure (5,6). Alternatively, it has been defined as the transplantation of all organs reliant on the celiac axis and superior mesenteric artery (SMA) (2). Modified multi-visceral transplantation (MMVT) is yet another variation of this that includes all the aforementioned organs except the liver (5). The currently accepted indications for such composite organ blocks are outlined in Table 1 (1). Reported outcomes in high-volume centres have markedly improved since Starzl’s initial report on the first human cases in 1989 (7). Currently, the anticipated 5-year patient survival rate ranges from 46% to 50% following MVT (6,8).

In-situ and ex vivo perfusion of organs has been investigated in recent years with a view to push the boundaries of criteria making organs acceptable for transplantation. Despite a record number of solid organ transplants (SOTs) reported in 2024, the ongoing discrepancy between supply and demand resulted in 31,853 patients dying while on the waitlist (9). The constant pressure of inadequate numbers of donors to meet supply has translated to an increased utilisation of donation following circulatory death (DCD) and expanded criteria donors (ECD) organs which have increased risk of early graft failure compared to standard criteria donors (9,10). Both ex vivo and in-situ perfusion technologies have been investigated to help mitigate the risk of transplanting a marginal organ already beyond the point of viability. Recent advances with normothermic regional perfusion (NRP) of DCD organs have led to improved outcomes in terms of early graft loss as well as reduced rates of ischaemic cholangiopathy, even in older marginal donors. Traditionally, in the DCD setting, procurement was performed using a super rapid recovery (SRR) technique with organs explanted as quickly as possible. NRP, however, involves a 2-hour period of in-situ perfusion which mitigates the effects of organ ischemia following treatment withdrawal. Studies of liver grafts that have utilised dual-hypothermic oxygenated perfusion (D-HOPE) after SRR have shown better liver outcomes than standard SRR followed by static cold storage (SCS) (11). There is growing interest in NRP where allowed by legislation, as the quality of grafts obtained function better than SRR followed by SCS (12). What is not known is whether SRR followed by D-HOPE is better, inferior or equivalent to NRP. The ability to therefore address questions like these in a large animal model and allow the focus to be more holistic (looking at all abdominal organs) rather than a single organ of interest is useful in developing our understanding in this area.

Rationale and knowledge gap

As the indications for MVT and NRP continue to broaden, focus of ongoing research has been aimed at safely expanding the donor pool. This necessitates the development of reliable ex vivo organ assessment and resuscitation protocols for grafts previously deemed unsuitable (13-17). NRP in particular has opened the door for further exploration into the use of DCD organs by reducing period of warm ischemia that particularly sensitive organs, such as the intestine are exposed to (13,18). The development of such protocols relies on the availability of high-fidelity large animal models as a bridge to clinical trials in humans. While large animal models are extensively used in pre-clinical transplantation research, currently no such model exists for the retrieval and testing of composite organ blocks, thereby impeding progress in this domain (19,20). Due to their physiological and anatomical similarities to humans, pigs are recognised as ideal pre-clinical transplantation models (21-23).

Objective

We describe a reproducible surgical technique for the safe retrieval of a multi-visceral organ block, comprising the porcine liver, pancreas, kidneys, and truncated small bowel, for pre-clinical research that our group has used while performing preservation, viability and reanimation studies of abdominal organs. We present this article in accordance with the ARRIVE reporting checklist (available at https://atm.amegroups.com/article/view/10.21037/atm-2025-1-168/rc).

Methods

Animals and husbandry

The study received approval from the Animal Ethics Committee of the South Australian Health & Medical Research Institute (approval number – SAM414.19). The experiments were conducted in compliance with Australian regulations and legislation concerning the use of animals in research, as specified in the Australian Code for the Care and Use of Animals for Scientific Purposes (8th ed., 2013) (24).

Following the refinement of the surgical technique in a prior study, twenty-six healthy adult female Large White pigs (Sus scrofa domestica) were procured from Roseworthy Piggery (Wasleys, South Australia) to assess the suitability and reproducibility of our method for the explantation of a multi-visceral organ block. The mean weight of the animals was 63.05 kg, with a range of 32.5 to 90.5 kg. A control group was not employed, as the study did not involve a comparative analysis of different retrieval methods. The primary outcomes of interest were the successful retrieval of the multi-visceral block without damage to any vital structures and the ability to remove the organs without causing the premature demise of the animal.

Each animal was housed individually in pens lined with rubber matting and allowed to socialize and acclimatize for a minimum of one week prior to experiments. Enrichment activities were provided in the form of balls and chains secured to the side of the pen. Animals were in sight of each other and able to touch each other through holes in the pens, with human contact also for socialisation. They were given food of 1 kg/d of grower pellets and water ad libitum.

Anesthesia

Prior to the surgical procedure, each pig was last fed at 4:00 p.m. on the preceding day. Subsequently, the animals were transported to the anaesthesia room, where they received 1–2 mg/kg IM xylazine as pre-medication. Anaesthesia was induced with 10 mg/kg IM ketamine and maintained with 2–3% isoflurane following endotracheal intubation with an appropriately sized tube based on the animal’s size and weight. An auricular vein was cannulated to facilitate the intraoperative administration of fluids and medications. Oxygen at 100% concentration was supplied at a rate of 2–3 L/min, and end-tidal CO₂ (etCO₂) levels were monitored to adjust ventilator settings, ensuring normocapnia (etCO₂ 35–45 mmHg). Depth of anaesthesia was monitored by trained staff throughout the procedure. Prior to great vessel cannulation, 5,000 units of IV heparin were administered. The model utilised was a non-recovery model and the retrieval of the multi-visceral block resulted in the humane death of the animal under anaesthesia.

Surgical technique

To conduct multi-visceral retrieval, a laparotomy was initially performed under stringent aseptic conditions using a cruciate incision, which combines longitudinal and transverse incisions, to access the abdominal cavity and ensure maximal exposure (Figure 1). The bladder, being entirely intra-peritoneal, was eviscerated and secured inferiorly to the drapes to create additional space within the operative field.

Figure 1 View of the abdominal organs in situ after laparotomy prior to commencing dissection. GB, gallbladder; LB, large bowel; Liv, liver; SB, small bowel; Sp, spleen.

Warm phase dissection

The colon, situated entirely on the left side of the abdominal cavity in the pig, was then rotated medially towards the right. This manoeuvre facilitates the dissection and exposure of the aortic bifurcation and the inferior vena cava. After incising the peritoneum overlying these vessels, each was circumferentially dissected and looped, ready for cannulation at the end of warm phase dissection. The peritoneal attachments of the colon were dissected off the abdominal wall with care as the colonic wall is significantly less muscular than in humans, which heightens the risk of perforation and faecal contamination. The spleen was mobilized by dividing its peritoneal attachments and a splenectomy was performed using an endoGIA laparoscopic stapler (Medtronic, Minneapolis, MN, USA) to control and divide the vascular pedicle. The distal duodenum, which is anchored to the retroperitoneum, is mobilised by dividing its attachments. In pigs, the distal duodenum is directly attached to the overlying mesocolon by a thick fold of peritoneum called the peritoneal duodenocolic complex (PDC). This fold must be meticulously dissected to separate the two structures and allow for excision of the colon later in the dissection (Figure 2).

Figure 2 The region of the retroperitoneum surrounding the duodenojejunal flexure. The green arrow indicates the reflected duodenum, and the blue arrow indicates the cecum. The yellow arrows highlight the prominent duodenocolic fold, which serves to anchor both structures together and must be meticulously divided to achieve complete colon mobilisation.

Following mobilization of the duodenum, the distal rectum was transected using the endoGIA stapler. Subsequently, the transected rectum and mobilised colon were passed around the duodenum. It is then advisable to reduce the length of the small bowel to approximately 100 cm. This length suffices for conducting functional assessments of viability without retaining an excessive length of small bowel, which is challenging to manage ex vivo and may sequester significant volumes of blood or perfusate when placed on the machine perfusion device, without providing additional benefits to the research model. To achieve this, the small bowel mesentery was divided using a Sonicision harmonic scalpel device (Medtronic) up to the required length, and the bowel was transected with another load of the endoGIA stapler (Figures 3,4). The redundant excess small bowel and the entire colon were then removed from the operative field for disposal.

Figure 3 Division of the small bowel mesentery using harmonic scalpel to shorten the small bowel. Note that pigs do not have anastomosing transverse vascular arcades in their mesentery as humans do, rather direct radial entry of feeding vessels from the mesentery into the wall of the bowel which can be seen (yellow arrow).

Figure 4 Appearance of the mesenteric veins and superior mesenteric vein (SMV) following division of the mesentery (green arrow). Note the cut edge of the mesentery (blue arrow) and the clear demarcation between viable and ischaemic bowel (yellow arrow) which is then divided with the stapler.

Attention was subsequently directed towards the upper gastrointestinal tract. A circumferential dissection of the stomach was conducted to mobilise it from just distal to the pylorus to the gastroesophageal junction (GEJ). Both the pylorus and distal oesophagus were double ligated with heavy polyester retraction tape. The stomach and abdominal oesophagus were then excised by dividing between the ligatures, facilitating their removal from the operative field. Dissection around the diaphragmatic crura at the GEJ must be performed with caution to avoid breaching the parietal pleura of the thoracic cavity, which could result in an iatrogenic pneumothorax. Any pneumothorax can rapidly lead to hemodynamic instability and potentially the premature demise of the animal. If a pneumothorax occurs, it can be identified by the inferior aspect of the diaphragm ballooning out, and the tension can be relieved by making a sufficiently large incision in the diaphragm. With the overlying stomach excised, the peritoneal attachments of the pancreas to the retroperitoneum were divided to facilitate the excision of the pancreas along with the rest of the block.

Each ureter was then visualised in the retroperitoneum and the peritoneum overlying the ureter was incised. The ureters were dissected retrograde towards each kidney, ensuring the preservation of the peri-ureteral blood supply. The kidneys were then fully mobilised by incising the overlying peritoneal attachments. Although the ureters are mobilised, they are not divided at this stage. The liver is the final organ mobilized as part of the block. The peritoneal attachments of the liver to the retroperitoneum and diaphragm were divided taking care not to injure the inferior phrenic vein which can cause troublesome bleeding if inadvertently injured (Figure 5). Additionally, the inferior vena cava traverses the superolateral aspect of the porcine liver at this point, and any damage at this location could lead to catastrophic haemorrhage.

Figure 5 The assistant retracts the left lobe of the liver medially and the peritoneal attachments anchoring the liver in the right upper quadrant are divided using an energy device or diathermy (blue arrow). The inferior phrenic vein is demonstrated (green arrow).

Once all organs constituting the block have been sufficiently mobilised, it is necessary to expose the supra-coeliac aorta proximally to facilitate cross-clamping. The assistant retracted the remaining organs towards the animal’s right side, and access to the aorta was enhanced by dividing the left crus of the diaphragm (Figure 6). This manoeuvre permits the application of a clamp to the aorta immediately as it enters the abdominal cavity.

Figure 6 The yellow arrow indicates the abdominal aorta, with the diaphragmatic crus above it divided. The green arrow indicates the origin of the splenic artery, which arises almost directly from the abdominal aorta after a very short celiac trunk, as observed in humans. This artery is seen extending cranially over the pancreas (P), which has been retracted medially by the surgeon’s hand.

After completion of this warm phase dissection, preparation was then made for vessel cannulation and perfusion. The expected appearance of the organ block at the end of warm phase dissection is demonstrated in Figure 7. After checking all organs were completely mobilised and the perfusion set primed with crystalloid solution the distal inferior vena cava (IVC) was ligated. Blood collection bags primed with anti-coagulant can also be readied if blood-based machine perfusion will be performed as part of subsequent experiments, necessitating the collection of autologous blood. This blood can be collected directly from the aorta at the time of great vessel cannulation.

Figure 7 The final appearance of the multi-visceral block at the conclusion of the warm phase dissection which is characterized by the successful isolation of the porcine liver (L), pancreas (P), small bowel (SB), and bilateral kidneys (K). The inferior vena cava is demonstrated by the blue arrow and the aorta by the red arrow. This appearance should be achieved without inflicting injury and maintaining the viability of the pig. This outcome signifies the effective execution of the protocol up to this stage.

To commence isolation and perfusion of the block, a clamp was applied across the proximal supra-coeliac aorta and an arteriotomy was made distally above the bifurcation to introduce the perfusion cannula. This was secured in place with the previously positioned ties. The supra-hepatic IVC was then cannulated with a large bore needle to vent venous blood from the animal, which may either be discarded or collected into blood bags for future use. In our protocol, a total of 2 L of chilled Hartmann’s solution was used as flush before perfusing the block with 2 L of chilled University of Wisconsin (UW) organ preservation fluid (Bridge to Life Ltd., Northbrook, IL, USA). During the perfusion process, ice was packed into the abdominal cavity of the animal to facilitate rapid cooling of the organs (Figure 8).

Figure 8 Ice slush has been placed around organ block while perfusion continues with UW solution for rapid induction of hypothermia. UW, University of Wisconsin.

Cold phase dissection

Once exsanguination was complete and the organs perfused with UW solution, the ice slush was removed. Both the distal and proximal aorta and IVC were transected. The ureters were divided as distally as possible and reflected superiorly. An en bloc dissection in the plane between the retroperitoneum and spine from caudal to cranial was completed by retracting the liver supero-anteriorly in the operating surgeon’s non-dominant hand, while the attachments of the great vessels to the posterior abdominal wall are divided sharply with scissors (Figure 9). Once these attachments were divided, the entire multi-visceral block was lifted out of the abdominal cavity en bloc.

Figure 9 The liver is retracted supero-anteriorly in the operating surgeon’s non-dominant hand (yellow arrow) while the attachments of the great vessels to the posterior abdominal wall are divided. Artery clips are applied to lumbar vessels prior to transection for subsequent ligation on the back-table (blue arrow).

The appearance of an explanted multi-visceral block during subsequent machine perfusion on a normothermic perfusion rig is demonstrated in Figure 10. Upon completion of the procedure, the only organs remaining within the abdominal cavity at the end of the procedure were the reproductive organs and the urinary bladder.

Figure 10 Appearance of the multi-visceral block once cannulated for normothermic preservation with liver (L), pancreas (P), kidneys (K) and truncated small bowel (SB) all visible. Ureteric catheters have been placed for the collection of urine, the bile duct cannulated for collection of bile and a catheter placed in the duodenum to administer glucose for viability assessment.

Results

In this series, all 26 procedures were executed successfully, resulting in the retrieval of a viable multi-visceral block without unintended damage to critical structures. The mean operative duration for these procedures was 108.3 minutes, with a range of 57 to 179 minutes. Each animal was humanely euthanised under anaesthesia through exsanguination as the multi-visceral block was removed. The removal of a metabolically active multi-visceral block (as tested by ATP generation, oxygen consumption and carbon dioxide production, fluorescein angiography and testing of the glucose-insulin axis and GLP-1 production) during preservation and ex vivo reanimation confirmed the validity of our method of retrieval (Figure 11). The reader is invited to review the details surrounding the viability assessment methodology which have been published previously (25,26).

Figure 11 Appearance of the small bowel during performance of fluorescein angiography ex vivo to demonstrate adequate perfusion as part of viability testing of the multi-visceral block.

Discussion

We foresee two distinct situations where the retrieval of an intact multi-visceral block as described here would be advantageous to researchers engaged in work surrounding abdominal organ transplantation. Firstly, for progressing techniques relating to MVT incorporating the organs retrieved as a bloc. The second would be to investigate the feasibility of storing, assessing and resuscitating multiple organs together ex vivo which would then be split and destined for individual recipients after confirming viability. This is in line with proposed projects to establish organ assessment and reconditioning centres (ARCs), which aim to recondition and store organs ex vivo, releasing them as required to recipient centres, acting as a capacitor for organ supply (27). The advantage of preserving multiple organs from the same donor en bloc would be to reduce the number of individual machine perfusion devices and consumables required per organ as up to 5 organs could be preserved at once.

Critical points during dissection and retrieval

To complete such major abdominal dissection in pigs, a comprehensive understanding of comparative anatomy is required to safely retrieve the block and prevent the premature demise of any animals. For information regarding relevant anatomical differences pertinent to the procedure, the reader is directed to this review of comparative anatomy between pigs and humans (28). Several critical steps during the procedure must be meticulously performed to avoid inadvertent injury, haemorrhage, or faecal contamination.

Firstly, the colon, which is not included in the composite block, needs to be separated from the duodenum in order to excise it. The proximal colon is densely adhered to the duodenum via the PDC which needs to be carefully divided to separate the two structures. Secondly, the splenic artery arises very close to the aorta after a typically short coeliac trunk (~15 mm), rendering it susceptible to injury during the exposure of the proximal abdominal aorta and the medial rotation of the pancreas (Figure 7). As previously noted, any inadvertent injury to the diaphragm can lead to the rapid onset of a pneumothorax and the premature demise of the animal if not decompressed into the abdominal cavity. Lastly, the inferior phrenic veins run along the inferior aspect of the diaphragm and can be inadvertently injured, resulting in significant bleeding during dissection around the superior surface of the liver or the GEJ.

Possible advantages for use of the composite organ block in translational research

The holy grail of organ preservation for transplant is reliable organ viability testing and possibly intervening ex vivo with customized repair strategies for damaged organs to optimize them for their intended purpose and minimise injury. An important advantage of retrieving this composite organ block is the ability to evaluate intact physiological axes during ex vivo perfusion and define functional tests that assess residual activity and recovery as opposed to injury, and thereby set useful bench parameters that can be used to clinically discern between useable and non-useable organs.

An additional benefit of the multi-visceral block is its capacity to evaluate customised immunosuppression protocols, which is critically important when incorporating the small bowel as an allograft, given its highly immunogenic nature (31). While small animal models are valuable for establishing proof of concept, large animal models are essential for translating these concepts into clinical applications. This necessity arises from the significant differences in pharmacokinetics and pharmacodynamics between small and large animals, which can lead to divergent conclusions (32). The enhanced genetic complexity and greater homology to humans observed in large animal models, such as pigs (60% homology compared to 40% in rodents), render them significantly more appropriate for evaluating the practicality, safety, and overall efficacy of customized immunosuppression protocols prior to conducting human trials (32,33). Pigs possess a well-characterized and comprehensively understood major histocompatibility system, a fully sequenced and modifiable genome, and only two primary blood groups (A and O) (34-36). These attributes facilitate their use as an immunological model. In the future, this model may be employed to explore innovative approaches to ex vivo graft modification, such as the targeted depletion of gut-associated lymphocytes, with the aim of enhancing immunological outcomes in multi-visceral transplants that include the small bowel.

While other research groups have investigated multi-visceral retrieval using porcine models, our study uniquely reports the complete retrieval of all abdominal organs currently utilized in clinical transplantation, achieved in a manner that simulates donation from a heart-beating donor. In contrast to slaughterhouse models, our technique can be conducted in an operating theatre under sterile conditions, closely replicating the clinical environment. This approach is therefore well-suited for use in allo-transplantation models, which are essential following initial proof of concept before proceeding to human trials. Such pre-clinical studies should aim to replicate the anticipated clinical setting as closely as possible (37). Although not undertaken as part of this study, our model could also be adapted to become a DCD model by causing death by lethal injection under general anaesthesia following heparinization (controlled DCD) and starting dissection in 10 minutes or death by lethal injection under anaesthesia and starting the procedure after 30 minutes (uncontrolled DCD). In a DCD model, following great vessel cannulation, the cannulas can be connected to an oxygenated perfusion circuit to establish an NRP model. Following this, the remainder of the dissection can be conducted as described. Another group has detailed an ischemia-free method for retrieving all abdominal organs, including the full length of the small bowel and colon, bladder and reproductive organs (38). In transplantation models, the inclusion of these additional organs is undesirable due to their lack of clinical relevance and the complications they introduce during subsequent machine perfusion, particularly the excessive oedema and fluid sequestration observed in the bowel during subsequent machine perfusion (29). A DCD model for retrieving similar organs has been documented; however, it utilizes organs from slaughterhouse pigs, where achieving sterility is not feasible (39). It only reliably replicates an uncontrolled DCD scenario not commonly encountered clinically in countries where controlled DCD donation predominates. We recognize however that variations in legislative frameworks governing animal research across different jurisdictions can influence the feasibility of various models and utilising organs from recently deceased livestock may present an ethically acceptable and cost-effective alternative in certain contexts. We propose that our model is likely to demonstrate superior applicability across diverse experimental contexts, including ex vivo perfusion and allotransplantation. It offers flexibility in simulating various donor types and serves as a reproducible surgical training model, alongside its research applications.

NRP for donation after circulatory death is seeing increasing uptake as a superior method of organ procurement, allowing greater utilisation of organs that were previously deemed unsuitable. The suitability of organs, however, remains largely determined by markers of cell damage and nebulous criteria for the point of no return, as currently, the perfusion is in situ and only for two hours. What is not known is whether a proportion of organs currently deemed unusable can improve in function if maintained in a homeostatic environment that supports cellular activity. A large animal model that can be used to elucidate mechanisms of injury beyond hypoxia/ischemia and repair beyond the simple administration of oxygen would be useful to establish frameworks for progression into uncontrolled DCD donation that will allow for further expansion of the donor pool.

Cost of the experimental work

It is well recognised that large animal experimental work is expensive to undertake (40). Despite this, large animal models are an essential link in the bench-to-bedside chain of translational research because of the high fidelity offered by animals such as pigs with close anatomical and physiological similarities to humans (19). The most significant expenses in this protocol come from the cost of the animals themselves ($201 USD per pig), husbandry services provided during acclimatisation ($805.28), UW organ preservation solution ($380 USD per litre) and high-cost surgical disposables such as the ultrasonic dissector and endoscopic stapler device ($1,650 USD combined). Excluding the cost of facility hire which will be highly variable between centres, the total cost of each operation performed was $4,692.28 USD. While few authors disclose in great detail costs incurred for their specific protocols, our costs for animal procurement and husbandry are similar to those described by others suggesting that the costs described should be generally applicable (37).

Conclusions

Robust large-animal models are required to undertake the necessary pre-clinical translational research and have so far been lacking. By following the described technique, it is possible to remove a composite organ block composed of the porcine liver, pancreas, small bowel and both kidneys. The technique described above closely mimics the situation of a retrieval in a brain-dead donor, but with small modifications, the technique is also suitable to mimic a DCD model. If desired, NRP techniques could also be employed in this setting. There are multiple possible uses for this block after explantation. Either each organ can be separated and subjected to different investigations or the entire block can be kept together which allows for a variety of tests of organ function to be performed during preservation that rely on intact metabolic and hormonal axes between the organs. Reproducible and safe surgical techniques of multi-visceral retrieval like the one described here will facilitate the use of translational large animal models while optimising the useful data obtained per animal.

Acknowledgments

The authors would like to acknowledge the staff of South Australian Health and Medical Research Institute Preclinical Imaging and Research Laboratory (PIRL) for their expert care and attention provided to the animals throughout these experiments.

Reporting Checklist: The authors have completed the ARRIVE reporting checklist. Available at https://atm.amegroups.com/article/view/10.21037/atm-2025-1-168/rc

Data Sharing Statement: Available at https://atm.amegroups.com/article/view/10.21037/atm-2025-1-168/dss

Peer Review File: Available at https://atm.amegroups.com/article/view/10.21037/atm-2025-1-168/prf

Funding: This work was supported by Kidney, Transplant & Diabetes Research Australia (KTDRA) (grant number: 2021/24-QA25217) via The Hospital Research Foundation (THRF); and Health Services Charitable Gifts Board (HSCGB) of South Australia.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://atm.amegroups.com/article/view/10.21037/atm-2025-1-168/coif). reports that. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study received approval from the Animal Ethics Committee of the South Australian Health & Medical Research Institute (approval number – SAM414.19). The experiments were conducted in compliance with Australian regulations and legislation concerning the use of animals in research, as specified in the Australian Code for the Care and Use of Animals for Scientific Purposes (8th ed., 2013).

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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Cite this article as: Barnett DR, Bhattacharjya R, Bastian J, Kanhere A, Daniel D, Bhattacharjya S. A standardised and reproducible method for en bloc multi-visceral organ retrieval in a porcine model. Ann Transl Med 2026;14(2):15. doi: 10.21037/atm-2025-1-168