[Diagnostic utility of the anti-Mullerian hormone in companion animals]

The anti-Mullerian hormone is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. The initial identification of this hormone in canine and feline serum was achieved in 2011. Meanwhile, a variety of studies have demonstrated its clinical significance as a tool in the endocrine diagnosis. This review summarizes the current knowledge about anti-Mullerian hormone in small animal reproduction and describes future opportunities for its diagnostic usage.

3D printed cannulas for use in laparoscopic surgery in feline patients: A cadaveric study and case series

OBJECTIVE

To evaluate custom 3D printed laparoscopic cannulas (3DPC) in a feline cadaveric abdominal surgery model and report their use in two live feline subjects.

STUDY DESIGN

Experimental cadaver study, live subject case series.

ANIMALS

Ten feline cadavers; two feline subjects.

METHODS

Custom 3DPCs were initially modeled in a PLA filament material and then created in an autoclavable dental resin for use in live patients. The surgery time, number of surgical collisions and cannula complications were recorded during cadaver procedures before and after use of 3DPCs. Cannula complications were recorded during live procedures and patients were followed to suture removal to record any incisional complications.

RESULTS

There was a significant reduction in mean surgical time (125.6 vs. 95.2 min, p = 0.03), mean number of instrument collisions (6.8 vs. 2.6, p = 0.03), and mean number of cannula complications (10 vs. 2.2, p = 0.03) with the use of only 3DPCs during the procedure. During the live procedures the use of the 3DPCs was successful and no postoperative complications occurred at the incision sites.

CONCLUSION

The use of customized 3DPCs may improve surgical dexterity and decrease complications in advanced procedures and was not associated with any clinical complications in two cats. The use of 3DPCs in veterinary medicine may allow for wider practice of laparoscopic techniques in small animals.

Anti-Müllerian hormone as a diagnostic tool to identify queens with ovarian remnant syndrome

OBJECTIVES

Ovarian remnant syndrome (ORS) is suspected when heat signs occur in spayed individuals, but further diagnostic procedures are necessary to exclude other possible oestrogen sources, such as the adrenal gland or exogenous supplementation. Anti-Müllerian hormone (AMH), secreted by granulosa cells or Sertoli cells, serves to differentiate sexually intact from gonadectomised animals and has been described in dogs as a tool for diagnosing ORS. The aim of this study was to evaluate if AMH determination can be used to diagnose ORS in cats.

METHODS

AMH was measured with a chemiluminescence immunoassay in serum samples of 15 sexually intact, 9 spayed and 16 cats with a history of heat signs after spaying. Abdominal ultrasound (n = 13), vaginal smears (n = 7), progesterone measurement (n = 5) and laparotomy (n = 14) were used to determine the presence of ovarian tissue. After surgery, a histological examination of the obtained tissue was performed in the cats with suspected ORS.

RESULTS

In 15 cats with ORS the AMH serum concentrations were significantly higher than in spayed cats (n = 10; P = 0.025) and significantly lower than in sexually intact cats (n = 15; P = 0.001). Among the cats with ORS, the highest AMH serum concentrations were measured in the queens with cystic ovarian alterations and in one cat from which a whole ovary was obtained. The cat with the lowest AMH serum concentration had a simultaneous high progesterone serum concentration. Cats with ORS did not show any heat signs after surgical removal of the ovarian tissue.

CONCLUSIONS AND RELEVANCE

A single determination of AMH in blood serum is a useful diagnostic tool for the diagnosis of ORS in cats, regardless of the hormonal activity of the remnant ovarian tissue.

A Comparison of Times Taken for the Placement of the First Portal and Complication Rates between the Veress Needle Technique and the Modified Hasson Technique in Canine Ovariectomy Laparoscopic Surgery

Minimally invasive surgery is increasingly being used in veterinary medicine. Laparoscopic procedures have several advantages compared with open surgery. These include the magnification of the field of surgery, reduced post-surgical pain and associated stress, reduced post-operative infection rates, and decreased hospitalization time. The establishment of a pneumoperitoneum is a critical step; however, this procedure can prolong the operation time, and most of the complications associated with laparoscopic surgery have been attributed to the insertion of devices into the abdominal cavity. Two main techniques have been employed to create pneumoperitoneum: the closed-entry method using the Veress needle and the open Hasson technique. The first portal is necessary to start insufflation and, subsequently, to realize the operative channel to insert the laparoscopic instruments into the abdomen. Many authors have compared the time necessary to create the first portal using different techniques in human medicine, but studies on this topic in veterinary medicine are lacking. In the veterinary medicine literature, complications associated with the creation of a pneumoperitoneum and the placement of ports include spleen, bowel, or bladder injuries; pneumothorax; and subcutaneous emphysema. The aim of the present study was to compare the times required for the placement of the first portal and the creation of pneumoperitoneum, and the rates of intraoperative complications using the Veress needle technique (VNT) and the open modified Hasson technique (MHT). The sample population comprised 30 female dogs who underwent laparoscopic ovariectomies. The dogs were randomly organized into two groups and two different entry techniques were used: Veress needle (VNT = group A) and the modified Hasson technique (MHT = group B). Complications related to abdominal entry were classified as major, in cases of organ perforation, and minor, in cases of subcutaneous emphysema and gas leakage. The VNT and MHT required 374.0 s and 242.9 s, respectively, for the placement of the first portal and for establishing pneumoperitoneum (p < 0.05). Their major complications rates were 20% and 0%, respectively (p < 0.05). Their minor complications rates were 20% and 35%, respectively (p < 0.05). No surgical procedures required laparotomy. The MHT was associated with a lower major complication rate and required less time to create the first portal, compared with the Veress needle technique.

Single Incision Laparoscopic Surgery (SILS) in Small Animals: A Systematic Review and Meta-Analysis of Current Veterinary Literature

In veterinary surgery, single incision laparoscopic surgery (SILS) techniques have been described since 2009, and, in recent decades, many authors have reported the application of SILS in small animals, thus, promoting the wide dissemination of this novel approach among veterinary laparoscopists. The aim of this literature review is to provide a critical evaluation of the scientific reports on SILS in the field of small animal laparoscopic surgery. A comprehensive literature review was performed including from 1 January 2009 to 1 July 2020. The following data were recorded from each study: the design, year of publication, surgical procedure, species, number of animals included, and surgical time. The type of SILS technique and type of control group technique were evaluated. In total, 90 articles were identified through database searches and manual searches. The qualitative analysis showed that most of the articles were retrospective studies, without a control group or case series. A meta-analysis was performed on the eight controlled studies, showing that SILS ovariectomy and gastrointestinal procedures had a comparable surgical time to multiport techniques. The study of the articles available in the veterinary literature did not allow for an adequate meta-analysis of the published results, especially regarding post-operative pain, evaluations of surgical times, and post-operative complications in comparison to multiport techniques. Therefore, veterinary surgeons who want to employ these techniques must consider the real advantages of SILS techniques.

Uptake of exogenous estrogen as a differential diagnosis of ovarian-remnant-syndrome in a bitch: a case report

Background

Clinical signs of heat in bitches that have been previously spayed are often associated with the presence of ovarian remnant syndrome. The inclusion of exogenous estrogens as a differential diagnosis in this regard is often ignored and may lead to misinterpretation of the case.

Case presentation

Herein, we report a case of exogenous estrogen exposure over several months to a 6.5-year-old spayed crossbred bitch, weighing 8.4 kg. The bitch presented in the clinic because of suspected ovarian remnant syndrome. Castration was performed within the first 6 months after birth. Important endocrine parameters measured at the first appointment were Anti-Müllerian hormone (< 0.01 ng/mL), progesterone (0.36 ng/mL), estradiol-17ß (20.7 pg/mL), and luteinizing hormone (< 0.1 ng/mL). After an extensive conversation with the owner, it was revealed that she was using an estrogen spray because of severe menopausal symptoms. After the owner stopped using this spray, the symptoms of the bitch disappeared.

Conclusion

Therefore, the uptake of estrogens should be a differential diagnosis for symptoms of the ovarian remnant syndrome. A detailed anamnesis is crucial to identify the source of estrogen in the environment of the affected bitch.

Evaluation of combined assessments of serum anti-Müllerian hormone and progesterone concentrations for the diagnosis of ovarian remnant syndrome in dogs

OBJECTIVE

To determine the usefulness of combined assessments of serum anti-Müllerian hormone (AMH) and progesterone (P4) concentrations for diagnosis of ovarian remnant syndrome (ORS) in dogs.

DESIGN

Prospective case series.

ANIMALS

602 bitches that had previously undergone ovariohysterectomy or ovariectomy without hysterectomy and that were being evaluated for ORS.

PROCEDURES

Serum AMH and P4 concentrations were measured in a single serum sample obtained from each of the 602 dogs; results were classified as positive, negative, or inconclusive. Following AMH testing, submitting veterinarians were offered reimbursement for shipping and histologic evaluation of any tissue removed during treatment of dogs for which serum samples had been assessed.

RESULTS

Tissue samples were provided from 53 of 55 dogs that underwent surgical abdominal exploration. Of 48 dogs with histologically confirmed ORS, 25 were positive for both AMH and P4 and 23 were positive for AMH or P4 or test results were inconclusive. No dogs with histologically confirmed ORS were negative for both AMH and P4. Tissue samples that included no ovarian tissue were obtained from 5 dogs that were positive for both AMH and P4. In 2 dogs that were negative for both AMH and P4, no ovarian remnant was identified and no tissue was removed at the time of exploratory surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that combined determination of AMH and P4 concentrations in a single serum sample can be an effective diagnostic test for spayed dogs suspected to have ORS. Histologic analysis of excised tissues to assess the completeness of surgical treatment in dogs with ORS is warranted.

A systematic review of complications related to laparoscopic and laparoscopic-assisted procedures in dogs

OBJECTIVE

To evaluate and report the quality of the scientific literature reporting complications associated with laparoscopic and laparoscopic-assisted procedures in client-owned or healthy research dogs and to report and illustrate laparoscopic complications related to individual organ systems.

STUDY DESIGN

Systematic review.

ANIMALS

Client-owned or healthy research dogs.

METHODS

A literature review was performed by using PubMed and CAB abstracts for English-language studies providing descriptions of complications related to laparoscopic and laparoscopic-assisted procedures in dogs. Study selection used PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Quality assessment was performed by using a MINORS (Methodological Items for Non-Randomized Studies) scoring system and a grading scale of level of evidence. Descriptive statistics were used.

RESULTS

In total, 741 manuscripts were identified, with 64 manuscripts eligible for data extraction and quality assessment. The most represented organ system was the female genital tract, represented by 22 (34.4%) studies. The most commonly reported intraoperative and postoperative complications were related to abdominal entry and portal incisions, respectively. In 53 of 54 non-randomized studies, high risk of bias was found. Forty-eight (75%) studies provided level III or IV evidence.

CONCLUSION

This report provides an updated review of complications related to laparoscopic and laparoscopic-assisted procedures in dogs, classified by organ system. The overall quality of evidence was low, limiting direct comparison of complication rates between studies.

CLINICAL SIGNIFICANCE

There is a need for implementation of standardized criteria for defining complications, study time frames and greater numbers of high quality prospective randomized trials in veterinary laparoscopy to permit comparison of complication and conversion rates between published studies and across organ systems.

Single-Port Laparoscopic Treatment and Outcome of Dogs with Ovarian Remnant Syndrome: 13 Cases (2010-2018)

Ovarian remnant syndrome (ORS) is a condition resulting from incomplete removal of ovarian tissue during ovariectomy and/or ovariohysterectomy. Single-port laparoscopy (SPL) is an alternative to ventral midline laparotomy for treatment of ORS. Medical records of 13 client-owned female dogs who underwent SPL for the treatment of ORS were retrospectively reviewed to evaluate surgical technique and outcome. Dogs who had undergone a previous attempt at open ovariectomy or ovariohysterectomy were included. Major intraoperative complications did not occur and conversion to open laparotomy was not required. In 1 dog, an SPL + 1 technique was used, in which an additional port was placed cranial to the single-port device to aid in dissection and tissue manipulation. Median surgical time was 45 min (range, 30-90 min). Clinical signs related to estrus had resolved in 11 of 13 dogs with a median follow-up time of 18 mo. Two of 13 dogs were lost to follow-up at 3 mo postoperatively; however, signs of estrus had resolved at time of last follow-up. SPL treatment for ORS was feasible and successful in this cohort of dogs. Reduced surgical time was found in this study compared with previous reports investigating multiple-port laparoscopic treatment of ORS.

Establishment of Renal Failure Models by Laparoscopy in Bama Pigs Which Underwent Partial Nephrectomy and Radical Contralateral Nephrectomy

Introduction

The miniature pig possesses unmatched advantages as an animal model because of its high homology with humans. Our experiment aimed to build a chronic renal failure (CRF) model in pigs via laparoscopy.

Material and Methods

Laparoscopic surgery was performed twice to build a CRF model. The first surgery was a left partial nephrectomy and the second was a right radical nephrectomy. Pigs were grouped by the total renal tissue to be resected: ⅔, ¾ or ⅚. Physiological parameters (rectal temperature and heart rate), haematological parameters (WBC and RBC) and renal function (serum creatinine - CR and blood urea nitrogen - BUN) were measured preoperatively and every week postoperatively.

Results

After renal resection the pigs manifested chronic renal failure. Heart rate and body temperature declined to varying degrees over 12 postoperative weeks. No significant difference was observed between the different groups. The result of renal function tests found that postoperative serum CR and BUN in all groups were continuously elevated, and the level of serum CR at two weeks post procedure differed very significantly from its preoperative value (P < 0.05). BUN was significantly elevated at one week (P < 0.05). The renal function decreased significantly faster in the ⅚ group than in the other two groups. The trend of renal function change was similar among groups, but progress was slower in the ⅔ and ¾ groups.

Conclusion

⅚ kidney resection was the optimal miniature pig model of CRF.

A laparoscopic approach for removal of ovarian remnant tissue in 32 dogs

BACKGROUND

Surgical treatment of ovarian remnant syndrome (ORS) in dogs usually necessitates large celiotomies and considerable manipulation of organs because of the relatively deep position of ovarian remnant tissue, large patient size, and often encountered adhesions. In women, laparoscopic treatment of ORS is successful and has significant advantages over laparotomy. Since laparoscopic ovariectomy has significant advantages over open ovariectomy in dogs, including reduced surgical stress and postoperative pain and shorter convalescence period, the rationale for a laparoscopic approach of canine ORS is evident. Feasibility and efficacy of a laparoscopic approach for treatment of ORS in dogs was prospectively evaluated using a standardized protocol for diagnosis, treatment, and follow-up. Treatment success was evaluated by histology of removed tissues, postoperative hormone testing, and long-term clinical follow-up.

RESULTS

Thirty-two client-owned predominantly medium and large breed dogs diagnosed with ORS underwent abdominal ultrasound for ovarian remnant localization prior to laparoscopic surgery for removal of ovarian remnants. Tissue dissection and excision was performed using a vessel sealing forceps. Laparoscopy subjectively enabled detailed visibility and facilitated detection and removal of suspected ovarian tissue in all cases. Histology confirmed ovarian origin of removed tissue in all dogs. Additionally, a GnRH stimulation test was performed in fourteen dogs after a median follow-up of 10.5 months, which verified absence of residual functional ovarian remnant tissue in all dogs. Median surgery duration was 97.5 min and mean total convalescence duration, subjectively scored by owners, was 1.5 ± 0.7 days. No major complications occurred. Adhesions were observed in 79% of the dogs, complicated the surgical approach, and significantly affected surgery duration (85 versus 109 min; p = 0.03). Minor hemorrhage occurred in 12% and significantly increased surgery duration (95.5 versus 128 min; p = 0.02). Trendelenburg position and lateral tilting of the patient were essential for proper access to ovarian remnants. GnRH stimulation test results and/or absence of clinical signs indicative of ORS after a median follow-up period of 22.5 months confirmed treatment efficacy in all dogs.

CONCLUSION

Laparoscopic surgery for ORS in dogs is effective with minimal complications and short convalescence and can successfully replace the conventional, more invasive open surgical procedure.

Laparoscopy for the treatment of ovarian remnant syndrome in four dogs and two cats

Objective: To describe the clinical workup and laparoscopic treatment of ovarian remnant syndrome in dogs and cats. Material and methods: After confirming the diagnosis with some or all of the following tests – vaginoscopy with cytology, hormonal tests, and ultrasound – laparoscopic removal of the ovarian remnants was performed. A three-portal technique was used in the four dogs and a two-portal technique in the two cats. Results: All patients recovered well and were discharged the same day. No post-operative complications occurred in any patient. Conclusion and clinical relevance: Overall, in the hands of an experienced laparoscopic surgeon, laparoscopic removal of ovarian remnants appears to be a safe procedure in dogs and cats. In addition, laparoscopy offers the advantages of excellent visualization and a reduced morbidity for the patient. Careful case selection and complete pre-operative workup to rule out co-morbidities or underlying neoplasia are important. As with any laparoscopy the surgeon should always be prepared to convert to an open laparotomy if necessary.

Advances in endoscopic surgery for small animal reproduction

Although endoscopic surgery entered its "golden era" in the mid-1980s, it is still advancing at a tremendous pace. Novel surgical techniques and devices are continuously developed and applied, and new indications (and/or contraindications) for the use of endoscopic surgery are routinely reported in the literature and subjected to systematic assessments. Although endoscopic surgery (laparoscopy in particular) has already become established as the gold standard in human medicine, it has yet to be proven as a viable alternative to open surgery in the field of veterinary medicine. The advantages of minimally invasive surgery include better intra-operative visualization, reduced postoperative pain, reduced scar formation and increased postoperative mobility. Therefore, it is reasonable to expect that the application of this will continue to expand. Small animal reproduction, a field within the broad discipline of veterinary medicine, has already recognized and begun to reap the benefits of endoscopic surgery. Herein, we retrospectively review the most recent successful novel applications of endoscopic surgery in the small animal reproduction system to provide small animal reproductive surgeons with important knowledge to help improve their own veterinarian medical practice.