The Potential of Minimally Invasive Techniques in a Tailored Diagnostic and Therapeutic Strategy for Acute Necrotizing Pancreatitis

INTRODUCTION

Acute destructive pancreatitis (ADP), a severe form of acute pancreatitis (AP), is characterized by significant necrosis of pancreatic tissue and is associated with high morbidity and mortality [1–3]. The management of this disease requires a multidisciplinary approach combining accurate diagnosis, individualized treatment strategies, and careful monitoring to address both local and systemic complications. This thesis provides a comprehensive review of diagnostic and therapeutic approaches for ADP based on recent research findings and clinical guidelines [2][4]. Recent advances in surgical management, including minimally invasive techniques, have contributed to a decline in postoperative mortality rates in Russia: from 15.4 % in 2017 to 12.96 % in 2018 [3]. This reduction is attributed to a combination of intensive conservative therapy during the early phase of the disease (enzyme toxemia) and minimally invasive surgical interventions in the late phase (sequestration) [3][5].

The diagnosis of AP is based on clinical, laboratory, and imaging findings. Patients typically present with acute abdominal pain accompanied by elevated serum amylase and lipase levels, which remain the diagnostic gold standard [6–8]. However, in suspected severe or destructive pancreatitis, further assessment of pancreatic necrosis and complications such as infected necrosis or walled-off necrosis is essential [9][10]. Biomarkers such as serum cytokines and pancreatic amylase show promise in predicting AP severity and identifying high-risk patients, enabling earlier intervention [1][11]. Imaging modalities, including computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP), are critical for confirming the diagnosis and assessing severity. CT is particularly valuable for detecting pancreatic necrosis, while MRCP provides detailed visualization of the pancreatic duct [1][12][13]. Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are also useful for evaluating pancreatic duct abnormalities, with EUS demonstrating high sensitivity and specificity [12]. Prognostic biomarkers such as C-reactive protein (CRP > 150 mg/L) and procalcitonin are reliable indicators of necrotizing pancreatitis and infected necrosis, respectively [1][8]. The Revised Atlanta Classification categorizes AP severity into mild, moderately severe, and severe forms based on organ failure and local complications, facilitating early risk stratification [7][14][15].

Treatment paradigms for ADP have evolved toward minimally invasive, multidisciplinary, and personalized approaches [16–19]. A step-up strategy for infected pancreatic necrosis begins with endoscopic or percutaneous drainage and escalates to more invasive procedures if necessary [20][21]. This approach reduces the risk of multiorgan failure and procedural complications [22]. Minimally invasive techniques, including endoscopic transgastric or percutaneous drainage, effectively manage acute peripancreatic fluid collections and walled-off necrosis. For extensive necrosis, minimally invasive necrosectomy is preferred [23][24]. Meta-analyses confirm that laparoscopic and robotic methods reduce intraoperative blood loss, hospital stay, and surgical site infections compared to open surgery, without increasing mortality [25][26]. However, these techniques require skilled surgeons and careful patient selection [3][25]. The aim of this study is to analyze treatment outcomes in patients with acute necrotizing pancreatitis and determine the most effective algorithm for implementing minimally invasive drainage techniques to reduce complication rates, decrease mortality, and improve clinical outcomes.

MATERIALS AND METHODS

This prospective cohort study included 136 patients with destructive acute pancreatitis (AP) admitted to the I.V. Davydovsky City Clinical Hospital (Moscow, Russia) between 2019 and 2024. Patients with biliary or postoperative AP were excluded due to distinct pathophysiological and clinical profiles. A historical control group of 140 patients treated prior to standardized minimally invasive protocols was analyzed for comparative outcomes. The cohort comprised adults aged 22–75 years (mean: 51.0 ± 15.2). All patients with confirmed acute necrotizing pancreatitis (ANP) and fluid collections underwent image-guided closed drainage (ultrasound-guided percutaneous aspiration of pancreatic, retroperitoneal, or lesser sac collections) as first-line intervention. Laparoscopic drainage was performed when ultrasound visualization was inadequate (e.g., due to colonic pneumatosis, obesity, or adhesions), irrespective of disease extent. For localized necrosis (≤30 % gland involvement), drainage served as definitive therapy. For necrosis >30 % (CT-confirmed), drainage preceded laparoscopic necrosectomy with continuous aspiration systems. Open surgery was reserved for anatomically complex cases or failed minimally invasive approaches.

All patients received protocolized conservative care per clinical guidelines, including: Antisecretory therapy (proton pump inhibitors); Aggressive fluid resuscitation; Prophylactic anticoagulation; Broad-spectrum antibiotics (carbapenems/piperacillin-tazobactam); Systemic detoxification (albumin, crystalloids); Metabolic correction (glucose/electrolyte monitoring)

Disease severity was classified using a modified Atlanta criterion:

• Edematous pancreatitis
• Acute necrotizing pancreatitis: Focal (≤30 % necrosis); Massive (30–60 %); Total/subtotal (>60 %); Biliary pancreatitis (distal choledochal pathology-associated).

Prognostic Assessment

Physiological scores: SAPS, APACHE II/III, Glasgow Coma Scale

Organ dysfunction: MODS, SOFA

Pancreatic-specific: Ranson, Glasgow, Balthazar CT Severity Index (CTSI)

Systemic inflammation: SIRS criteria

Imaging Protocol

Initial ultrasound: Evaluated pancreatic dimensions, necrosis foci, fluid collections (peripancreatic, pleural, peritoneal), ductal dilatation, and vascular patency (Doppler). Contrast-enhanced CT: Gold standard for diagnosing ANP and complications. Quantified necrosis extent using CTSI (Balthazar score + necrosis percentage). Provided detailed assessment of retroperitoneal involvement and hepatoduodenal anatomy.

Statistical Analysis

Patients were stratified by necrosis extent (Table 1). Continuous variables expressed as mean ± SD; categorical variables as percentages. Institutional review board approval and informed consent were obtained.

RESULTS

Patient Severity Distribution: At admission, disease severity was stratified as moderate (39.5 %), severe (37.1 %), and critical (23.4 %).

Evolution of Management Protocols (2019–2024): The study period saw enhanced conservative strategies, including:

1. Extracorporeal detoxification (e.g., plasmapheresis, continuous renal replacement therapy).
2. Early enteral nutrition via endoscopic nasojejunal tube placement.
3. Broad-spectrum antibiotics (carbapenems/piperacillin-tazobactam) initiated within 24 hours.
4. Multimodal analgesia anchored by prolonged epidural anesthesia (ropivacaine 0.2 %, 6–8 mL/hr, catheter level Th8–Th9).

Surgical Innovations

• Redefined laparoscopy: Transitioned from purely diagnostic to therapeutic: Enzymatic exudate aspiration from abdominal cavity/lesser sac; Drainage for continuous lavage; Necrosis mapping via laparoscopic pancreatoscopy;
• Step-up minimally invasive approaches: Ultrasound-guided percutaneous drainage for localized collections; Laparoscopic omentobursostomy via mini-ports; Electrosurgical necrosectomy (bipolar/monopolar devices).

Complication Dynamics

• Delayed drainage (>72h): Associated with 23.6 % abscess risk despite antibiotics.
• Focal necrosis (≤30 %): Localized abscesses (median onset: days 18–20) managed via image-guided drainage (success rate: 78.4 %).
• Massive necrosis (30–60 %): Required laparoscopic necrosectomy (Δ complications: 37.7 % vs. 11.4 % morta­lity).
• Total necrosis (>60 %): 73.5 % required early minimally invasive stabilization (laparoscopic lavage ± closed omentobursostomy).

Table 2 highlights the clinical advantages of the protocol used in Group 2, including reduced infectious complications (21.7 % vs. 62.8 %), mortality (12.4 % vs. 16.4 %), hospital stay (58 ± 9 days vs. 74 ± 12 days), ICU stay (18.8 ± 5 days vs. 25.3 ± 6 days), and disability rate (10.3 % vs. 18.2 %), with all comparisons reaching statistical significance (p < 0.01).

Mechanistic Insights

• Epidural analgesia: Correlated with accelerated leukocytosis resolution (days 2–4 vs. 5–7 in controls) and reduced leukocyte intoxication index (Δ = 1.8, p = 0.007).
• Early enteral nutrition: Associated with 2.3-day earlier bowel function recovery (p = 0.03).
• Laparoscopic step-up: Reduced late-stage sepsis by 4.1-fold (OR = 0.24, 95 % CI 0.12–0.49).

Operative Trends

• Staged necrosectomy: Performed in 67.0 % of severe cases via:
• Laparoscopic transperitoneal access (84.2 %);
• Retroperitoneal monoport (15.8 %).
• Reintervention triggers: SOFA score progression (Δ ≥ 3), infected necrosis (CT Gas+), or sequestra > 5 cm.

Limitations: Single-center design and heterogeneous necrosis quantification methods may limit generalizability.

DISCUSSION

This study demonstrates that a necrosis-extent-stratified protocol significantly optimizes outcomes in ANP, reducing mortality, infections, and hospitalization. Our findings align with global trends favoring minimally invasive step-up approaches but refine them by emphasizing tailored intervention timing and modality based on objectively quantified necrosis.

Stratification Superiority: The 24 % mortality reduction (p = 0.03) highlights that focal necrosis (≤30 %) is optimally managed with percutaneous drainage alone, avoiding unnecessary surgery. This corroborates Gallyamov et al.’s emphasis on less invasive first-line interventions [2][9]. For massive necrosis (30–60 %), staged laparoscopic necrosectomy with continuous lavage reduced sepsis by 41.1 % (p < 0.001). This supports the “step-up” concept but adds that early laparoscopy (within 72h) mitigates bacterial translocation by preserving peritoneal integrity [23]. Paradoxically, total/subtotal necrosis (>60 %) benefited from early open debridement (within 48h), reducing endogenous intoxication mortality by 27.5 % (p = 0.007). This challenges purely minimally invasive dogma but aligns with Bensman et al., suggesting extensive necrosis requires rapid source control [21].

Adjunct Innovations: Prolonged epidural analgesia accelerated leukocytosis resolution (Δ = 3 days, p = 0.007), likely by blunting sympathetic-mediated inflammation. Early enteral nutrition reduced bowel paralysis by 2.3 days (p = 0.03), preventing bacterial overgrowth. Ultrasound-guided drainage within 24h prevented abscess formation despite antibiotics (23.6 % risk if delayed), underscoring urgency. Our 11.4 % mortality in massive necrosis is lower than the 15–20 % in recent meta-analyses, attributable to strict necrosis quantification (vs. subjective assessment) and standardized detoxification [24]. The 65 % infection reduction exceeds the 40–50 % achieved in step-up trials, likely due to our protocol’s mandatory early drainage [23]. Limitations and Future Directions: Single-center design and retrospective controls limit generalizability. While necrosis stratification proved robust, inter-rater variability in CTSI scoring requires attention. Multicenter validation (ideally randomized) is needed, particularly for the open approach in total necrosis.

CONCLUSION

This protocol’s efficacy stems from precision stratification — minimally invasive techniques for limited necrosis and timely open debridement for extensive disease. Integrating non-surgical adjuncts (epidural analgesia, enteral nutrition) amplifies outcomes. It offers a practical, resource-efficient framework adaptable to diverse settings.