Surgical management of bladder rupture in adult horses: An uncommon problem meets a novel solution

This clinical commentary is to accompany the interesting case report from Olivier et al. (2025) describing the standing, laparoscopic repair of a urinary bladder rupture using barbed suture in an adult horse. This condition, known more formally as cystorrhexis, is known to be more common in foals than adult horses. Furthermore, cystorrhaphy, the repair of a urinary bladder tear, is more complicated and difficult in the adult horse for multiple reasons. Consequently, laparoscopic approaches have been utilised to gain access to the urinary bladder (Schott & Woodie, 2018); and standing laparoscopy has also been performed on the bladder in order to avoid the risks and potential expense of general anaesthesia (Hendrickson & Lee, 2024; Schott & Woodie, 2018). Given the severity of the clinical disease associated with cystorrhexis and the difficulty inherent in its repair, standing laparoscopy is especially advantageous in this scenario and was utilised with success in this case by Olivier et al. The aim of this commentary is to describe the pathophysiology and diagnosis of the clinical syndrome seen in horses with cystorrhexis, describe medical treatment avenues, and briefly discuss surgical management, particularly as it pertains to the use of barbed suture material and laparoscopic methods. Cystorrhexis has been described to occur in adult horses most commonly secondary to parturition, whether or not dystocia was encountered. Trauma is probably the second-most common cause of cystorrhexis in the adult, followed by urethral obstruction (McNally & Walsh, 2015). Anaesthetic recovery has also been implicated in previous case reports (Pankowski & Fubini, 1987; Walesby et al., 2002) and is most likely the inciting cause in the current case report, despite the fact that the field castration and its associated anaesthetic recovery were reportedly without significant incident. Depending on the size and location of the tear, the onset of clinical signs may be rapid or more insidious, and may or may not require surgical management (McNally & Walsh, 2015; Schaer & Orsini, 2014; Schott & Woodie, 2018). The case described in the current report developed signs of depression and dysrexia within 2 days post-operatively, which is most consistent with cystorrhexis at the time of anaesthetic recovery. These clinical signs, combined with varying degrees of pollakiuria (barring urethral obstruction) and straining to urinate, are the most likely to be noted in the adult, as abdominal distention is less recognisable in the acute stages. The peritonitis that develops secondary to uroabdomen may be either septic or sterile, at least initially; and this likely plays a role in the mild colic signs, dysrexia or anorexia, and ileus that may be seen clinically (McNally & Walsh, 2015). Electrolyte abnormalities seen with cystorrhexis are consistent with post-renal urinary dysfunction. However, renal injury is a significant concern when formulating a treatment plan as many of the drugs commonly given to systemically compromised horses in a pro-inflammatory state are nephrotoxic (e.g. flunixin meglumine and polymyxin B). Typical clinicopathologic abnormalities on venous blood gas and serum chemistry analysis are acidaemia/acidosis, hyperkalaemia, azotaemia, hypochloraemia and hyponatraemia, the severity of which will depend on the severity and chronicity of the case. Peritoneal creatinine and urea nitrogen will also increase, with the highest values and differences from peripheral blood being seen within ~24 h post-rupture, then decreasing as compensatory mechanisms equilibrate concentrations between the blood and peritoneal fluid (Genetzky & Hagemoser, 1985; Schaer & Orsini, 2014). The diagnosis of uroabdomen in the horse described in the full version of this case report serves as an excellent template for case work-up. A thorough physical examination and history are obviously indicated and can provide clinical suspicion for cystorrhexis. Interestingly, one older study involving experimentally induced cystorrhexis in two mature horses found that physical examination findings such as tachycardia and tachypnoea did not manifest until ~50 h post-rupture (Genetzky & Hagemoser, 1985), which is consistent with the timeline seen in the case described here by Olivier et al. (2025). Establishing the horse's volume status via packed cell volume, total solids and lactate measurement is crucial, as affected horses will tend to not drink sufficiently, likely due to depression from uraemia in addition to electrolyte abnormalities. A complete blood count is also indicated to further characterise any abnormalities and obtain a baseline at the initiation of treatment, and serial serum amyloid A (SAA) measurements may help guide future therapy such as decisions regarding anti-inflammatory and antimicrobial usage. A chemistry panel is also obviously indicated to characterise and address electrolyte abnormalities and azotaemia as well as to monitor renal function as treatment progresses. Blood gas analysis may also be helpful to provide information regarding acid–base status. Ultrasonographic evaluation of the abdomen is crucial, as the presence of a large volume of anechoic to hypoechoic free fluid is highly suspicious for uroabdomen given other consistent clinical signs and history. Abdominocentesis can then be performed to assess cytology, total solids, lactate and peritoneal creatinine. A peritoneal creatinine:serum creatinine ratio of >2:1 is effectively diagnostic for uroabdomen at any time point (Genetzky & Hagemoser, 1985). The presence of calcium carbonate crystals within the peritoneal fluid on microscopy is also a diagnostic feature that is unique to mature horses versus foals (Schaer & Orsini, 2014). Rectal palpation can be expected to reveal a flaccid, relatively empty bladder. Palpation for cysto-/urethro-liths is also important to help rule out urethral obstruction. Transrectal ultrasonography was also used successfully by Olivier et al. to recognise the tear at the apex of the urinary bladder [see fig. 2 of the full version of the article (Olivier et al., 2025)]. However, definitive diagnosis prior to surgery is made via cystoscopy. The endoscope should be disinfected with a high-level disinfectant and aseptically rinsed thoroughly prior to introduction into the surgically prepped urethra/vulva. Importantly, carbon dioxide should be used for insufflation instead of room air due to the risk of air emboli (Donaldson et al., 1998), which can be fatal, particularly in an already compromised case. Cystorrhexis can be considered a medical emergency first and a surgical emergency second. As in the case reported here (Olivier et al., 2025), antimicrobials, anti-inflammatories and fluid therapy are indicated to address peritonitis, prepare for surgical intervention, replace volume and normalise the patient's electrolyte status as much as possible. A Foley catheter should be placed in the bladder aseptically, and the balloon should be inflated with the indicated volume of sterile saline or water. Relieving the uroabdomen is critical to halt the process of reabsorption of creatinine and other excreted electrolytes, so placement of an abdominal drain should be performed as quickly as possible. A 32-French chest tube works well for this purpose, and extra holes can be cut into the portion of the tube to be placed intra-abdominally to mitigate interference from the omentum. Gastroprotectants are likely to be beneficial due to the effects of uraemia on the gastric mucosa. Additionally, acute kidney injury and chronic kidney disease in humans have been shown to induce gastrointestinal dysbiosis, which has, in turn, been shown to affect the progression of renal disease (van Galen, 2025). Speculatively, this is a possible contributory mechanism by which the horse in the current report developed profuse diarrhoea. As such, microbiome support such as probiotic and/or prebiotic supplements may be considered if the horse is eating. Volume support via intravenous (IV) fluid therapy is critical, which also allows for the correction of electrolyte derangements. Hyponatraemia, if significant, should not be corrected at a rate faster than 0.5 mEq/h (10 mEq/day) in order to avoid the risk of pontine demyelination (Fielding, 2015; Magdesian, 2014). Correction of hypochloraemia should progress in accordance with the hyponatraemia, as the commercially available IV fluids for horses contain relatively large concentrations of sodium chloride to achieve the appropriate osmolarity. Hyperkalaemia is typically the rate limiting factor affecting the systemic stability of the case, particularly if proceeding to general anaesthesia. Treatment should be initiated if serum potassium concentrations have reached >6.0 mmol/L (Fielding & Magdesian, 2015), though clinical signs such as muscle fasciculations and cardiac arrhythmias can occur at concentrations of >5.5 mmol/L (Schott & Woodie, 2018). Calcium gluconate should be supplemented IV as a cardioprotectant. Depending on the severity, treatments may progress from oral sugar (e.g. molasses) to IV dextrose, exogenous insulin, potassium-wasting diuretics and sodium bicarbonate. Though physiologic saline has been touted as the best option for treating hyperkalaemia, it could theoretically be problematic as an acidifying solution and may also not be practical for high volume IV fluid therapy in horses depending on its commercial availability. Therefore, other replacement fluids with a low potassium concentration may be used/necessary. This has also been shown to be effective in other species with hyperkalaemia secondary to post-renal urinary obstruction in cats (Cunha et al., 2010; Drobatz & Cole, 2008). However, frequent and consistent monitoring of serum electrolyte concentrations is obviously indicated. Once stabilised, surgical correction is generally indicated, and there are multiple reports in the veterinary literature describing standard ventral approaches (Pankowski & Fubini, 1987; Salcedo-Jimenez et al., 2025), standing transurethral approaches in mares (Higuchi et al., 2002; Jones et al., 1996; Salcedo-Jimenez et al., 2025), as well as laparoscopic repair, both under general anaesthesia (Walesby et al., 2002) and standing (Hendrickson & Lee, 2024; Tuohy et al., 2010). Though case reports exist of smaller tears being managed medically (Peitzmeier et al., 2016), the expense and high rate of morbidity with prolonged medical therapy often necessitate surgery. The benefits of minimally invasive standing surgery are well established (Martens et al., 2018). However, laparoscopic suturing is an uncommon procedure in equids and is technically challenging. The advent of barbed suture has substantially decreased this technical difficulty by eliminating the need for knot tying. This is a critical improvement, as the combination of inexperience (i.e. uncommon procedures) and a high degree of technical difficulty creates a surgical scenario rife with possibilities for complications and/or failure. Fortunately, previous work under ex vivo conditions has demonstrated that barbed suture performs as well as conventional suture in the equine bladder using laparoscopic techniques (Ruzickova et al., 2016). Further work also demonstrated that uni-directional and bi-directional sutures perform similarly whether used in a single- or double-layer closure, and the technique for tissue closure with barbed sutures has been previously described (Videos S1 and S2, Figures S1 and S2, Major et al., 2017). However, it is important to note that these tests were both performed in otherwise normal, ex vivo bladders, so the effects of tissue injury and other variables were not accounted for. As such, most surgeons would advocate for double-layer closure in any cystorrhaphy to ensure a water-tight seal. Olivier et al. (2025) demonstrated in the current case report, for the first time in a clinical case, that the use of barbed suture for standing, laparoscopic cystorrhaphy in a mature horse is indeed possible. This report also highlights the importance of post-operative management in cases of cystorrhaphy. A patent, functioning urinary catheter is crucial to prevent the build-up of pressure within the bladder and subsequent failure of the repair. Continued medical management is also critical to provide a tapering level of supportive care as the patient (hopefully) improves. In the face of a severely compromised case with an uncommon problem, this group was able to effect aggressive, targeted therapy both pre- and post-operatively and successfully utilise a novel surgical technique to achieve a successful outcome. There are no funders to report for this submission. No conflicts of interest have been declared. Not required for this clinical commentary. Figure S1. Figure S2. Video S1. Video S2. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.