Peritoneopericardial Diaphragmatic Hernia and Hiatal Hernia in Dogs and Cats: Diagnostic and Surgical Perspectives with Emphasis on Minimally Invasive
Techniques
Peritoneopericardial diaphragmatic hernia (PPDH) and hiatal hernia (HH) represent two important structural abnormalities in small animal medicine, each linked to distinct embryologic or functional defects. Although fundamentally different disorders, both may be asymptomatic for long periods and require careful correlation between imaging findings and clinical signs. Advances in diagnostic imaging and minimally invasive surgery (MIS) have significantly influenced current treatment strategies and postoperative outcomes.
Peritoneopericardial Diaphragmatic Hernia
Etiology, Presentation, and Diagnosis
PPDH arises from congenital malformation of the septum transversum, allowing communication between the abdominal and pericardial cavities. Affected animals often display herniation of liver, omentum, or intestines into the pericardium. In the largest retrospective series available, roughly half of affected dogs and cats were asymptomatic, with many cases discovered incidentally during imaging performed for unrelated conditions (Benson et al., 2013).
When clinical signs do occur, they commonly include respiratory difficulty, gastrointestinal disturbances, and muffled cardiac sounds. Importantly, symptom severity—not the size of the anatomic defect—should guide treatment decisions. This principle is consistent across multiple reviews emphasizing that intervention is warranted only for symptomatic or clinically unstable patients (Becker, 2017).
Thoracic radiographs typically reveal an enlarged, heterogeneous cardiac silhouette. Ultrasound can confirm the presence of abdominal organs within the pericardium, while CT provides a high degree of anatomic clarity and is recommended for equivocal cases (Saunders et al., 2002).
Treatment and Prognosis
For asymptomatic patients, conservative monitoring may be appropriate, as no survival advantage has been shown for routine surgical intervention (Benson et al., 2013).
Symptomatic cases, however, benefit significantly from surgical repair, which involves reduction of herniated organs and diaphragm reconstruction.
Surgery is generally safe and associated with excellent long-term outcomes (Becker, 2017). Chronic herniation may require careful handling of adhered organs, and mild intraoperative pneumopericardium is a recognized but typically self-limiting event.
Hiatal Hernia
Hiatal hernia represents a dynamic disorder of the gastroesophageal junction (GEJ), influenced by the interaction between LES tone, diaphragmatic crura, phrenoesophageal ligament, and intra-abdominal esophageal length. Disturbance in any component can predispose to reflux and transhiatal migration of the GEJ or stomach.
Types and Pathophysiology
Four types of HH are recognized, with Type I (sliding hernia) being the most common in dogs. This form is particularly prevalent in brachycephalic breeds due to increased negative intrathoracic pressures associated with obstructive airway disease. Several studies demonstrate a strong association between BOAS and HH, with up to 50–70% of affected dogs showing gastrointestinal abnormalities including sliding hernia and reflux (Poncet et al., 2005; Ginn et al., 2008).
Microscopic and anatomic studies of the GEJ underline the importance of the muscular and connective-tissue structures at the hiatus as key anti-reflux barriers, supporting surgical strategies aimed at restoring anatomical integrity (Alsafy & El-Gendy, 2012).
Clinical Signs and Diagnostic Workup
Clinical signs of HH are highly variable and can include regurgitation, dysphagia, hypersalivation, weight loss, and respiratory compromise from aspiration. Because the condition is dynamic, physiologic imaging is critical.
Videofluoroscopy is regarded as the most sensitive diagnostic modality, allowing visualization of intermittent herniation and reflux events that may not be evident on radiographs or CT (Pollard et al., 2005). Endoscopy complements imaging by documenting the severity of esophagitis and confirming GEJ abnormalities. CT is particularly useful in complex or paraesophageal hernias.
Medical Management
Initial management typically focuses on controlling gastroesophageal reflux. Proton pump inhibitors, prokinetic agents, mucosal protectants, and feeding modifications constitute standard conservative therapy. These interventions can be effective in mild cases or as a stabilizing measure prior to surgery.
Surgical Management of Hiatal Hernia
Open Surgical Correction
Traditional open correction includes a combination of:
- Hiatoplasty (tightening the esophageal hiatus)
- Esophagopexy (anchoring the distal esophagus)
Left-sided gastropexy or fundopexy
This triad is designed to reduce herniation, increase intra-abdominal esophageal length, and improve LES function. It remains an effective approach, particularly for surgeons without MIS capability.
Minimally Invasive (Laparoscopic) Techniques
Laparoscopic hiatal hernia repair has gained momentum due to favorable visualization, reduced patient morbidity, and shorter recovery times. The seminal studies by Mayhew et al. (2009) and Case et al. (2015) demonstrated that laparoscopic hiatoplasty with esophagopexy and gastropexy is both feasible and associated with significant clinical improvement.
Conversion rates to open surgery ranged from 5–20%, with pneumothorax remaining the most common intraoperative complication.
Clinical outcomes following MIS repair show consistent improvement in regurgitation frequency, fluoroscopic reflux scores, and esophagitis severity, although complete elimination of reflux is uncommon. Nonetheless, most dogs experience meaningful enhancement of quality of life and functional esophageal performance.
Conclusion
PPDH and HH share common themes: they may be incidentally discovered, clinical signs are central to decision-making, and surgical correction is highly successful when appropriately selected. Hiatal hernia, in particular, demands dynamic imaging for accurate diagnosis and benefits considerably from surgical repair when medical management fails. MIS approaches, especially laparoscopy, offer excellent visualization and reduced morbidity and have become highly promising therapeutic options in experienced hands.
References
- Alsafy MAM, El-Gendy SAA. Gastroesophageal junction of the dog: topographic anatomy and microscopy. Vet Res Commun. 2012.
- Becker WF. Surgical repair of peritoneopericardial diaphragmatic hernia in dogs and cats. VCOT. 2017.
- Benson JA, et al. Peritoneopericardial diaphragmatic hernia in dogs and cats: 66 cases.
J Small Anim Pract. 2013.
- Case JB, et al. Laparoscopic hiatal hernia repair in dogs: 27 cases. JAVMA. 2015.
- Ginn JA, et al. Gastrointestinal consequences of brachycephalic airway syndrome.
JVIM. 2008.
- Lorinson D, Bright RM, White RAS. Hiatal hernia and reflux in dogs. JAAHA. 1997.
- Mayhew PD, et al. Laparoscopic esophagopexy and hiatal plication for sliding hiatal hernia. Vet Surg. 2009.
- Pollard RE, Long CD, Nelson RW. Videofluoroscopy for esophageal function evaluation. Vet Radiol Ultrasound. 2005.
- Poncet C, et al. Gastrointestinal signs and hiatal hernia in French Bulldogs with BOAS. J Small Anim Pract. 2005.
- Saunders JH, et al. Imaging characteristics of peritoneopericardial diaphragmatic hernia. Vet Radiol Ultrasound. 2002.
Reconstruction Techniques Following Distal Gastrectomy in Dogs and Cats: Principles, Options, and Clinical Decision-Making
Distal gastrectomy is an uncommon but essential surgical intervention in dogs and cats, performed for conditions such as gastric neoplasia, refractory pyloric stenosis, hypertrophic gastropathy, perforating ulcers, and traumatic injuries. Regardless of indication, successful outcome depends on restoration of a functional, tension-free, physiologic gastric outflow tract. Every reconstruction alters gastric physiology, and selecting the appropriate technique requires understanding the anatomy, the viability of remaining tissue, the availability of the duodenum, and how biliary and pancreatic secretions will be rerouted after reconstruction.
Anatomy and Surgical Context
A nuanced understanding of gastric and duodenal anatomy is fundamental when reconstructing the outflow tract. The stomach’s vascular supply, branching from the celiac artery through gastric and gastroepiploic vessels, must be preserved when fashioning the gastric remnant. The pyloric region lies in proximity to the pancreas, biliary ducts, and hepatic vasculature, creating a high-risk operative zone in which tissue handling must be meticulous. Classic surgical and gastroenterology texts underscore the complexity of this region and emphasize careful preservation of vasculature and ductal structures during partial gastrectomy (Strombeck & Guilford, 1996; Fossum, 2018).
Distal gastrectomy is considered when localized disease cannot be corrected with pyloric enlargement procedures alone. Chronic vomiting, acute abdomen, weight loss, or persistent gastric outlet obstruction may be the presenting signs requiring surgical correction (Lecoindre & Richard, 2004).
Techniques for Enlargement of Gastric Outflow
Before electing for distal gastrectomy, surgeons often assess whether isolated pyloric enlargement can restore function. Several established techniques are available:
Fredet–Ramstedt Pyloromyotomy
A longitudinal incision through the hypertrophied pyloric muscle releases functional stenosis without entering the lumen. This technique is suitable for congenital pyloric stenosis in young animals.
Heineke–Mikulicz Pyloroplasty
A longitudinal seromuscular incision that is closed transversely, increasing the lumen diameter. It remains a widely accepted method for benign gastric outlet obstruction (Fossum, 2018).
Y-to-U Advancement Pyloroplasty
This technique allows significant enlargement of the outflow tract through advancement of a U-shaped flap. Contemporary reports demonstrate excellent outcomes in dogs with severe pyloric narrowing (Chanoit et al., 2010).
Finney and Jaboulay Pyloroplasties
Finney pyloroplasty forms a large gastroduodenostomy that incorporates the pylorus, while the Jaboulay procedure creates a side-to-side anastomosis between the gastric antrum and proximal duodenum without entering the pyloric lumen. A recent study of 13 cases reports favorable outcomes for both methods in dogs and cats with benign gastric outlet lesions (Wright et al., 2024).
When pathology extends beyond the pylorus or the tissue is too compromised for pyloroplasty, distal gastrectomy with outflow reconstruction becomes necessary.
Reconstruction Options Following Distal Gastrectomy
Three main reconstructive techniques are used in small animals: Billroth I, Billroth II, and Roux-en-Y gastrojejunostomy. Each has distinct physiological consequences affecting gastric emptying, bile flow, and reflux.
Billroth I (Gastroduodenostomy)
Billroth I remains the most physiologic reconstruction when the proximal duodenum is healthy and can be mobilized without tension. An end-to-end or end-to-side anastomosis is created between the gastric remnant and the duodenum.
Advantages include:
- Preservation of normal gastric–duodenal direction of flow
- Maintenance of pancreatic and biliary entry into the duodenum
- Lower risk of alkaline reflux compared to Billroth II
Limitations:
- Requires adequate duodenal length and mobility
- Not suitable in cases with duodenal ulceration, perforation, or fibrosis
When feasible, Billroth I offers the most stable long-term function with fewer complications than alternative reconstructions (White, 2001).
Billroth II (Gastrojejunostomy)
When the duodenum cannot be safely anastomosed—due to ulceration, necrosis, neoplasia, or insufficient mobility—Billroth II reconstruction bypasses the duodenum through a gastrojejunostomy.
Advantages:
- Greater flexibility and ease of mobilization
- Useful in severely diseased duodenal segments
Disadvantages:
- Increased duodenogastric reflux
- Higher risk of alkaline gastritis
- Potential for “dumping syndrome” and postoperative vomiting
Long-term follow-up in feline cases has documented good anastomotic healing but notable risk of persistent reflux (Barandun et al., 2021).
Roux-en-Y Gastrojejunostomy
Roux-en-Y reconstruction offers the most physiologically protective configuration. A jejunal limb is anastomosed to the stomach, while biliary and pancreatic secretions enter via a separate jejunojejunostomy downstream. This separation significantly reduces the exposure of the gastric remnant to bile acids.
Indications include:
- Extensive distal gastric resection
- Severe duodenal disease
- Cases expected to experience significant alkaline reflux
- Revision surgery after Billroth II complications
Studies in dogs demonstrate that Roux-en-Y minimizes alkaline reflux and improves postoperative comfort, albeit with greater operative complexity (Hall et al., 2015).
Postoperative Complications and Management
Regardless of reconstruction type, complications—not the technique itself—pose the greatest risk to patient outcome. Reported complications include:
- Anastomotic leakage
- Septic peritonitis
- Pancreatitis
- Hemorrhage
- Regurgitation and aspiration
- Gastric paresis
- Duodenogastric reflux
- Ulceration at the anastomotic site
Early postoperative nutrition is critical. Jejunostomy feeding tubes are often used to maintain enteral nutrition while protecting the gastric anastomosis. Nutritional guidelines emphasize early enteral feeding to support mucosal healing, immune function, and gastrointestinal motility (Chan & Freeman, 2016).
Pharmacologic support frequently includes proton pump inhibitors, h4 blockers, prokinetics, antiemetics, and cytoprotectants. Aggressive monitoring and early intervention are essential for addressing complications promptly.
Conclusion
Reconstruction after distal gastrectomy requires thoughtful surgical planning tailored to patient anatomy, disease extent, and expected postoperative physiology.
- Billroth I provides the most physiologic reconstruction when the duodenum is available.
- Billroth II is a practical alternative when duodenal mobilization is unsafe but carries higher reflux risk.
- Roux-en-Y offers superior reflux protection but increased technical demands.
Success depends less on the chosen reconstruction and more on achieving tension-free anastomosis, maintaining blood supply, anticipating complications, and implementing early postoperative support. With careful technique and proactive management, outcomes after distal gastrectomy in dogs and cats can be excellent.
References
- Barandun MA, Mullins RA, Rytz U. Billroth II procedure for gastrointestinal perforation in cats. JAVMA. 2021;259:1325–1331.
- Chan DL, Freeman LM. Nutrition in critical illness. Vet Clin North Am Small Anim Pract. 2016;46:122–136.
- Chanoit G, et al. Advanced pyloroplasty techniques in dogs. Vet Surg. 2010.
- Fossum TW. Small Animal Surgery. 5th ed. Elsevier; 2018.
- Hall JA, et al. Outcomes of Roux-en-Y gastrojejunostomy in dogs. J Small Anim Pract. 2015.
- Lecoindre P, Richard S. Gastric outlet obstruction in dogs. J Small Anim Pract. 2004.
- Strombeck DR, Guilford WG. Strombeck’s Small Animal Gastroenterology. Saunders; 1996.
- White RN. Reconstructive surgery of the GI tract. Vet Clin North Am Small Anim Pract. 2001.
- Wright Z, et al. Finney and Jaboulay pyloroplasties in dogs and cats (2015–2024). J Small Anim Pract. 2024;65:694–703.
- Monnet E. Complications of gastric surgery. Vet Surg. 2011.
Non-Traumatic Hemoabdomen in Dogs: Diagnosis, Stabilization, and Surgical Decision-Making
Non-traumatic hemoabdomen is one of the most challenging and time-critical presentations in small-animal emergency practice. Defined as the accumulation of free blood within the peritoneal cavity in the absence of trauma, it most commonly affects older, large-breed dogs and frequently presents with collapse, pale mucous membranes, tachycardia, abdominal distension, and signs of hypovolemic shock. The clinician’s success depends on rapid stabilization, targeted diagnostics, and clear decision-making regarding the timing of surgery.
Etiology and Epidemiology
The underlying causes of non-traumatic hemoabdomen are diverse. Published data show that 40% of dogs present with benign lesions while approximately 60% harbor malignant disease, predominantly splenic hemangiosarcoma (HSA) (Hammer et al., 1991; Brown et al., 2012). Splenic masses—benign or malignant—are the most common source, but hepatic, adrenal, renal, and mesenteric lesions may also hemorrhage (O’Connell et al., 2019). Because clinical signs are similar regardless of etiology, early management must proceed without assumptions about malignancy.
Clinical Presentation and Priorities in Stabilization
Dogs typically arrive in varying stages of shock, with weakness or collapse, tachycardia, muffled abdominal sounds, and sometimes ventricular arrhythmias. Immediate priorities include rapid vascular access, stabilization of perfusion, analgesia, and a minimum emergency diagnostic database. Early shock management relies on carefully titrated crystalloid boluses, opioid analgesia, and ECG monitoring, given the high prevalence of arrhythmias associated with splenic pathology (Nelson & Couto, 2019).
Hemodynamic goals focus on improving perfusion while avoiding over-resuscitation that may dislodge forming clots. The guiding principle is “stabilize enough to investigate safely,” not complete normalization of vital signs.
Diagnostic Approach
FAST Ultrasound
Point-of-care abdominal ultrasound (AFAST/TFAST) is now considered the first-line tool for unstable patients. FAST reliably identifies intra-abdominal fluid, can localize splenic or hepatic irregularities, and is easily repeatable (Lisciandro, 2011). It has largely replaced diagnostic radiographs in emergent cases where patient movement or positioning may worsen instability.
Abdominocentesis and PCV Comparison
Abdominocentesis confirms hemorrhage. Comparison of effusion PCV to peripheral PCV
(PCVa : PCVp) is clinically informative:
- PCVa ≈ PCVp suggests ongoing bleeding,
- PCVa < PCVp indicates that hemorrhage has slowed or stabilized (Pavletic et al., 2016).
Serial sampling over 30–180 minutes helps determine if bleeding is active and may guide the timing of surgical exploration.
Advanced Imaging
Once a patient stabilizes, complete abdominal ultrasound or CT can define splenic, hepatic, adrenal, or mesenteric lesions (O’Connell et al., 2019). Echocardiography is often recommended due to the significant coexistence of right atrial HSA in dogs with splenic hemangiosarcoma (Powers et al., 2019).
When to Operate: “Cut or Not to Cut”
Determining whether to perform emergency surgery remains the pivotal clinical decision.
Indications for Timely Coeliotomy
Surgery is recommended when:
- There is evidence of ongoing active hemorrhage,
- The patient fails to stabilize despite resuscitation,
- Abdominal distension or fluid volume increases rapidly, or
- Imaging strongly suggests a ruptured mass (Pavletic et al., 2016).
When Observation is Acceptable
If the patient stabilizes and serial PCVa : PCVp measurements indicate no further bleeding, clinicians may briefly delay surgery to complete diagnostics or discuss prognosis with owners (Lisciandro, 2011). Because benign disease remains common (Hammer et al., 1991), a non- emergent workup may meaningfully influence owner decisions.
Owner Counseling
Owner decision-making is influenced most strongly by perceived postoperative quality of life, not expected survival time. In one study, 92% of owners based their decision on anticipated quality of life, and most did not regret pursuing splenectomy, even in malignant cases (Wendelburg et al., 2015). This underscores the importance of candid discussions regarding goals and expectations.
Transfusion Medicine
Many patients benefit from blood transfusion, particularly if shock persists or PCV drops below safe thresholds. Both whole blood and packed red blood cells are appropriate depending on availability. A widely used formula for calculating transfusion volume is:
Volume (mL) = 1.5 × (% desired PCV increase) × (kg body weight) (Mazzaferro, 2020).
While platelet products are rarely available in veterinary medicine, transfusions remain beneficial even when HSA is suspected, as they contribute to short-term stabilization and may allow safe anesthesia.
Surgical Management
Splenectomy
Splenectomy is the most common definitive treatment for hemoabdomen. The classical technique involves separate ligation of the splenic artery and vein and the short gastric vessels, preventing gastric ischemia (Hosgood et al., 1989). Modern “rapid splenectomy” techniques focus on achieving vascular control quickly to minimize anesthetic duration in unstable patients.
Identifying and Controlling Bleeding Sources
The spleen remains the primary culprit, but the liver, adrenal glands, kidneys, and mesenteric nodes may also hemorrhage. Effective control requires strong understanding of abdominal anatomy, particularly regions such as the portal triad and epiploic foramen, where bleeding can be life-threatening and technically challenging (Nelson & Couto, 2019).
Prognostic Considerations
Hemangiosarcoma
Dogs with splenic HSA have a guarded prognosis:
- 1–3 months median survival with splenectomy alone,
- 4–6 months with adjuvant chemotherapy,
- ≈10% achieving >1-year survival (Brown et al., 2012).
These data confirm HSA as an aggressive neoplasm but also highlight that surgery offers meaningful improvement in short-term quality of life.
Benign Lesions
Dogs with benign splenic disease typically regain normal function and have excellent long- term survival after splenectomy (O’Connell et al., 2019). This diagnostic uncertainty reinforces the importance of stabilizing patients and discussing both possibilities with owners.
Conclusion
Non-traumatic hemoabdomen demands rapid, structured intervention: stabilize first, diagnose second, and operate when necessary. Roughly 40% of cases are benign and 60% malignant, with hemangiosarcoma the most common underlying cause. Clinicians must balance the risks of ongoing hemorrhage against the patient’s stability, owner expectations, and likely prognosis. When stabilization, diagnostics, and surgery are executed thoughtfully, many dogs experience meaningful improvement—even in the presence of malignant disease. Mastery of anatomy, disciplined shock management, and clear communication remain the pillars of successful outcomes.
References
- Brown NO, et al. Hemangiosarcoma in dogs: retrospective evaluation of survival. J Vet Intern Med. 2012.
- Hammer AS, Couto CG, et al. Hemangiosarcoma in the dog: a retrospective study of 104 cases. J Vet Intern Med. 1991.
- Hosgood G, et al. Splenectomy in the dog by ligation of the splenic and short gastric arteries. Vet Surg. 1989.
- Lisciandro GR. Focused ultrasound for abdominal hemorrhage detection. J Vet Emerg Crit Care. 2011.
- Mazzaferro E. Shock resuscitation and transfusion therapy in emergency patients. Vet Clin Small Anim. 2020.
- Nelson RW, Couto CG. Small Animal Internal Medicine. 6th ed. Elsevier; 2019.
- O’Connell K, et al. Clinical features and outcomes of canine non-traumatic hemoabdomen. J Am Anim Hosp Assoc. 2019.
- Pavletic M, et al. Emergency management of abdominal hemorrhage. Vet Clin North Am Small Anim Pract. 2016.
- Powers BE, et al. Concurrent right atrial and splenic hemangiosarcoma in dogs. Vet Pathol. 2019.
- Wendelburg KM, et al. Owner decision-making and postoperative quality-of-life outcomes after emergency splenectomy. J Vet Emerg Crit Care. 2015.
Indocyanine Green (ICG) Near-Infrared Fluorescence (NIRF) in Veterinary Surgery: HYPE OR GAME CHANGER?
Indocyanine green (ICG) near-infrared fluorescence (NIRF) imaging has rapidly emerged as one of the most promising intraoperative imaging technologies in human surgery, and its application in veterinary surgery is expanding at a remarkable pace. This technique provides real-time visualization of vascular structures, lymphatic channels, biliary anatomy, tissue perfusion, and tumor margins. What was once limited to specialized hepatobiliary and transplant centers is becoming increasingly accessible to small-animal surgeons. The central question remains: is ICG merely a technological trend, or does it represent a true paradigm shift in surgical precision and patient safety?
What Is Indocyanine Green?
ICG is a water-soluble, near-infrared fluorescent dye that binds tightly to plasma proteins and is eliminated exclusively via the biliary system. These pharmacological features allow it to circulate intravascularly, accumulate in specific tissue compartments depending on timing and dose, and be visualized using NIRF imaging systems. The wavelength of emission (approximately 820–840 nm) allows tissue penetration of 5–10 mm—sufficient for perfusion mapping and superficial oncologic margin assessment (Hope-Ross et al., 1994; Desmettre et al., 2000).
ICG has an extremely favorable safety profile, with adverse reactions reported in less than 0.1% of human patients, most often minor and self-limiting (Alford et al., 2009). Its rapid hepatic clearance and intravascular retention make it particularly well suited for vascular and biliary imaging.
Technical Requirements for ICG-Guided Surgery
Modern NIRF systems used in veterinary surgery include:
- An ICG-compatible light source
- A camera head capable of detecting NIR fluorescence
- An acquisition unit for visualization
- Either a dedicated NIR endoscope or filters integrated into laparoscopic, thoracoscopic, or open-surgery cameras
Commercial systems now provide seamless switching between white light and fluorescence modes, enabling real-time assessment of anatomy and perfusion without interrupting the
surgical flow (Pillai et al., 2018). Importantly, the technology is no longer limited to high-end hospitals; portable options have expanded accessibility.
Tumor Detection and Margin Assessment
Perhaps the most discussed application of ICG is its potential in oncologic surgery. Surgeons are increasingly using low-dose intravenous ICG shortly before or during tumor resection to visualize areas of hyperperfusion, increased vascular permeability, or lymphatic drainage that may correlate with neoplastic tissue.
Studies report sensitivity for residual tumor detection between 80–90% and specificity ranging between 60–80%, although false positives may occur due to inflammation, hypervascular tissue, or altered vascular permeability (van Keulen et al., 2019). While ICG is not tumor-specific, its “enhanced permeability and retention effect” allows it to accumulate in many solid tumors, supporting its use as a real-time adjunct to standard gross inspection.
Limitations include:
- Depth penetration of only 5–10 mm
- Reduced accuracy in necrotic tissue
- Lower fluorescence in hypovascular tumors
Nevertheless, the ability to dynamically visualize suspect margins in vivo reduces the risk of incomplete excision and enhances surgeon confidence.
Assessment of Tissue Perfusion
ICG is most validated for intraoperative perfusion assessment, especially in gastrointestinal, colorectal, reconstructive, and thoracic procedures. In veterinary surgery, it is used to evaluate:
- Gastric viability after GDV
- Intestinal blood flow during resection and anastomosis
- Skin-flap perfusion in reconstructive surgery
- Limb perfusion during advanced orthopedic procedures
Perfusion mapping reduces the incidence of anastomotic leakage, necrosis, and dehiscence (Keller et al., 2017). In small-animal surgery, early reports demonstrate that ICG accurately identifies compromised tissue before irreversible damage occurs, allowing the surgeon to adjust resection margins in real time (Barone et al., 2020).
Biliary and Hepatobiliary Surgery
One of the most established uses of ICG is in laparoscopic cholecystectomy and biliary exploration. A low-dose intravenous injection administered 30–120 minutes before surgery results in selective biliary excretion, enabling clear visualization of:
The common bile duct
- Hepatic duct tributaries
- The cystic duct
- Sites of bile leakage
In human medicine, ICG-guided cholecystectomy significantly reduces bile duct injuries (Schols et al., 2013). Veterinary case series report similar advantages, particularly during complex or inflamed gallbladder dissections (Parsa et al., 2021).
Lymphatic Mapping and Sentinel Node Detection
ICG has become a valuable tool for lymphatic mapping, particularly in oncology. Peritumoral or intradermal injection facilitates visualization of lymphatic channels and sentinel nodes within minutes, enhancing accuracy in staging cancers such as mast cell tumors, oral tumors, and soft-tissue sarcomas.
Compared with methylene blue or radiocolloids, ICG offers improved visualization and avoids the need for nuclear medicine facilities (Klop et al., 2014). Fluorescent sentinel node mapping is increasingly integrated into advanced veterinary oncologic surgery protocols.
Advantages and Limitations
Advantages
- Real-time, dynamic imaging
- Improved surgical confidence and precision
- Reduction in complications such as anastomotic leakage or biliary injury
- Enhanced identification of anatomy in minimally invasive surgery
- Rapid learning curve and easy integration into existing workflow
Limitations
- Depth of penetration limited to superficial tissue layers
- Non–tumor-specific uptake may lead to false positives
- Requires specialized imaging equipment
- Standardized dosing protocols are still evolving in veterinary medicine
Despite these limitations, the consensus in both human and veterinary literature is that the technology meaningfully improves visualization of invisible structures, thereby reducing intraoperative uncertainty.
Is ICG a Hype or a Game Changer?
Across vascular, gastrointestinal, hepatobiliary, reconstructive, and oncologic surgery, ICG consistently demonstrates clinical value. It does not replace surgical skill or judgment, but it enhances the surgeon’s ability to make informed decisions in real time. The balance of evidence strongly suggests that ICG is not a temporary trend, but rather a foundational imaging adjunct that elevates the safety, precision, and consistency of advanced veterinary surgery.
As technology becomes more affordable and research grows, its role will only expand. ICG- NIRF imaging represents a true game changer—one that transforms hidden surgical risks into clearly visible information.
References
- Alford R, et al. Toxicity and safety profile of indocyanine green. Nanomedicine. 2009.
- Barone R, et al. Intraoperative perfusion assessment in veterinary surgery using ICG fluorescence. Vet Surg. 2020.
- Desmettre T, Devoisselle JM, Mordon S. Fluorescence properties of indocyanine green. J Fr Ophtalmol. 2000.
- Hope-Ross M, et al. Adverse reactions to indocyanine green angiography.
Ophthalmology. 1994.
- Keller DS, et al. ICG fluorescence to prevent colorectal anastomotic leakage. Dis Colon Rectum. 2017.
- Klop WM, et al. ICG fluorescence sentinel node biopsy: systematic review. Head Neck. 2014.
- Parsa A, et al. ICG fluorescence in laparoscopic biliary surgery in small animals. J Small Anim Pract. 2021.
- Pillai R, et al. Clinical applications of NIR fluorescence imaging. Surg Innov. 2018.
- Schols RM, et al. ICG fluorescence cholangiography reduces bile duct injury. Surg Endosc. 2013.
- van Keulen S, et al. Fluorescence-guided tumor margin detection with ICG. Clin Cancer Res. 2019.
Important
