Use of the Ligasure vessel-sealing device for thoracoscopic peripheral lung biopsy in healthy dogs

Short-term outcomes of dogs and cats undergoing lung lobectomy using either a self-ligating loop or a thoracoabdominal stapler

OBJECTIVE

To assess clinical outcomes of lung lobectomies in dogs and cats using either self-ligating loops (SLLs) or thoracoabdominal (TA) staplers, aiming to inform sample size calculations for future superiority trials.

STUDY DESIGN

Retrospective study.

ANIMALS

A total of 72 dogs and 15 cats.

METHODS

Records from January 2003 to October 2023 at a single institution were reviewed. Cases with lung lobectomy performed via TA stapler or SLL with a minimum 14-day postoperative follow-up were included. Pre-, intra-, and postoperative data were collected, with outcomes of interest including the frequency of intra- and postoperative complications. Outcome comparisons between techniques were performed to inform sample size calculations.

RESULTS

A total of 101 lung lobectomies were performed. The TA stapler was used in 83 (82.2%) and the SLL in 18 (17.8%) lung lobectomies. Intraoperative complications were identified in 14/101 lung lobectomies (13.9%), including intraoperative hemorrhage in 12/101 lobectomies (11.8%) and air leakage in 2/101 lobectomies (1.9%). Postoperative complications were identified in 12/87 cases (13.8%), including 4 (4.6%) catastrophic complications and 5 (5.8%) major complications. All intra- and postoperative complications occurred in cases having undergone stapled lung lobectomy; however, no differences were identified between surgical technique and either intraoperative (p = .069) or postoperative complications (p = .112). A sample size of 103 lobectomies per technique group would be required for appropriate evaluation.

CONCLUSION

Lung lobectomy using either surgical technique provided a good short-term outcome in this population.

CLINICAL SIGNIFICANCE

Self-ligating loop lung lobectomy provided a comparable alternative to stapled lung lobectomy. Further studies are needed to assess technique superiority.

Histomorphological evaluation of thermal injury following palatoplasty performed with CO2 laser or LigaSure device in dogs with brachycephalic obstructive airway syndrome

The elongated soft palate is an abnormality that characterizes most brachycephalic dogs and contributes to the brachycephalic obstructive airway syndrome (BOAS). Palatoplasty is routinely performed in brachycephalic dogs; several surgical techniques exist. The use of surgical instruments such as monopolar electrocoagulation, CO2 or diode laser, bipolar vessel sealing device and harmonic shears has become routine to reduce the operating time, the intraoperative risk of bleeding and the postoperative oedema. This prospective study aimed to compare the histomorphological effect of a CO2 laser and LigaSure device in palates of dogs undergoing palatoplasty. Twenty owned brachycephalic dogs were included, 10 palatoplasties were performed using CO2 laser and 10 using LigaSure™ device. The dogs were positioned in sternal recumbency. A transoral approach was performed: the elongated soft palate was grasped with Allis forceps and brought rostrally, the palatoplasty was performed using the tonsillar crypts as anatomical landmarks. Surgical specimens were routinely fixed in 10 % formalin. Two sections perpendicular to the surgical margins were trimmed from each sample, paraffin-embedded and stained with hematoxylin and eosin (H&E). Tissue damage induced by the two types of surgical devices was graded (1-4, from minimal to severe) and the depth of thermal injury measured in μm on captured images (using an image analysis program - ImageJ). Mean values and standard deviations (SD) were calculated based on six measurements for each sample. The tissue damage was graded 3.7±0.48 in group LigaSure™ and 2.8±1 in group Laser. The mean depth of thermal injury was 874.94±184.92 μm in the LigaSure™ group and 451,76±137,86 μm in the Laser group. The comparison between the two groups showed significant lower grade and extension of thermal injury in the palate samples obtained with CO2 laser (p<0.05). Additionally, there is a lack of literature that correlates the histological changes with the clinical outcomes of the different palatoplasty methods in brachycephalic dogs. By comparing histological changes and clinical outcomes, we aim to provide valuable insights for optimizing the surgical approach for palatoplasty in brachycephalic dogs, ultimately improving postoperative outcomes for these patients.

Advances in Minimally Invasive Procedures of the Thoracic Cavity

Significant advances in veterinary minimally invasive surgeries and procedures have occurred in the past 10 years. These advances have been allowed due to continual research into optimizing working space through one-lung ventilation techniques and carbon dioxide insufflation. Additionally, minimally invasive surgery enthusiasts have joined forces with interventionalists and, in many cases, physicians to push the boundaries, minimize pain, suffering, and time away from owners with advances in a variety of procedures. Several larger multi-institutional retrospective studies on various disease processes allow veterinarians and owners to understand that minimally invasive approaches allow for outcomes comparable to traditional open surgery and, in some cases, may now be considered the standard of care in canine and feline patients.

Comparison between Image-Guided Transbronchial Cryobiopsies and Thoracoscopic Lung Biopsies in Canine Cadaver: A Pilot Study

Simple Summary

A definitive diagnosis for most pulmonary diseases is possible only through histopathological examination. The literature describes different methods of lung biopsy sampling depending on the case. However, for the diagnosis of diffuse interstitial pulmonary diseases and some peripheral neoplasms, the gold standard is represented by surgical lung biopsies. Given their invasiveness and the high percentage of risk for the patient, in most cases they are not carried out, resulting in a serious diagnostic gap. In human medicine, transbronchial lung cryobiopsies have been introduced as an alternative, which have shown high efficacy and reduced invasiveness. This study aims to evaluate the feasibility of the new technique in dogs by subjecting dog cadavers to pulmonary cryobiopsy and surgical lung biopsies, and to compare the samples obtained for histopathological quality. In total, 42 tissue samples were compared. Pulmonary cryobiopsies were smaller than surgical biopsies but with high levels of agreement upon histological evaluation. This study demonstrates the feasibility of the technique in dogs and the collection of specimens with size and histological features comparable to those from surgical biopsies.

Abstract

To date, the only method of sampling lung tissue with a high diagnostic yield is represented by surgical lung biopsies (SLB), which are highly invasive and have a high risk/benefit ratio. In humans, transbronchial lung cryobiopsies (TBLC) have recently been introduced, which are described to be less invasive and able to significantly increase diagnostic confidence in most patients with interstitial lung diseases. The aim of this study was to evaluate the feasibility and diagnostic yield of TBLC compared to SLB in small animals. A total of 21 pulmonary cryobiopsies under fluoroscopic and real-time CT fluoroscopic guidance and 21 video-assisted thoracoscopic surgery (VATS) lung biopsies were collected from three dog cadavers. Upon histological examination, cryobiopsy samples were smaller than VATS biopsies, but were still large enough to reach a specific diagnosis or to allow pattern recognition. Morphological features on TBLC and SLB were concordant in all cases. Cryobiopsy samples showed fewer artifacts and a higher percentage of alveolar tissue than VATS samples. TBLC is a feasible and useful alternative to SLB for lung histopathological examination in dogs. The effectiveness and reduced invasiveness of TBLC compared to SLB could represent many advantages in the diagnosis of diffuse lung diseases in small animals.

Decortication, thoracic omentalization, and pericardiectomy for treatment of severe fibrosing pleuritis in a cat

CASE DESCRIPTION

A 5-year-old spayed female domestic shorthair cat was evaluated because of an acute onset of dyspnea and open-mouthed breathing.

CLINICAL FINDINGS

Thoracic radiography revealed pleural effusion and signs consistent with restrictive pleuritis, and results of preoperative CT were consistent with diffuse, severe restrictive pleuritis, bilateral pleural effusion, and pulmonary atelectasis. Thoracocentesis yielded a red, turbid fluid that was identified as chylous effusion with chronic inflammation.

TREATMENT AND OUTCOME

Exploratory thoracotomy revealed diffuse, severe fibrous adhesions between the mediastinum, heart, lung lobes, and thoracic wall, with a thick fibrous capsule enveloping all lung lobes. Surgical treatment consisted of complete pleural decortication, pericardiectomy, and thoracic omentalization. The cat remained hospitalized for 6 days, receiving oxygen supplementation, multimodal analgesia, and supportive care. Long-term home care consisted of prednisolone administration, rutin supplementation, and provision of a low-fat diet. At recheck examinations 3-, 7-, and 20-weeks postoperatively, the cat remained tachypneic, but was otherwise clinically normal without dyspnea or respiratory distress. Follow-up thoracic radiography revealed improved pulmonary expansion, decreased pleural effusion, and resolved pneumothorax.

CLINICAL RELEVANCE

Surgical management of fibrosing pleuritis secondary to idiopathic chylothorax in cats has historically resulted in poor outcomes. This report details the first successful use of complete decortication in the surgical management of severe fibrosing pleuritis in a cat.

Use of a Bipolar Vessel-Sealing Device for Splenic Parenchymal Resection in Three Dogs and One Cat

Based on splenic abnormalities noted during surgery, four client-owned animals (three dogs, one cat) undergoing exploratory laparotomy were identified as candidates for partial splenectomy. In three cases, small mass lesions of the spleen were identified on elective exploratory laparotomy. In one case, the patient was referred for emergency surgery for diaphragmatic hernia with entrapment of stomach and spleen. The discovery of avulsion of a significant portion of the splenic mesentery led to the decision to perform partial splenectomy in this case. All animals included in the study underwent partial splenectomy by one of two board-certified veterinary surgeons at a multispecialty hospital between 2014 and 2018. The same type of bipolar vessel-sealing device was used in each surgery, and three of four partial splenectomy cases recovered uneventfully. One patient went into cardiopulmonary arrest hours after surgery and died; however, this is not suspected to be due to the described partial splenectomy technique. The bipolar vessel-sealing device is suitable for use in resection of the splenic parenchyma in some canine and feline patients. This technique is designed to decrease surgical time, provide effective hemostasis, and preserve the important functions of the spleen that are lost when total splenectomy is undertaken.

The feasibility and effectiveness of thoracoscopic transdiaphragmatic approach for lung biopsy in rabbits. A randomized study

PURPOSE

To assess the feasibility of thoracoscopic transdiaphragmatic approach for biopsy of all lung lobes and to determine the optimal intercostal space (ICS) for biopsy of each lung lobe.

METHODS

Ten rabbits were positioned in dorsal recumbency. Total thoracoscopy lung biopsy was made combined transdiaphragmatic approach and right ICS approaches. A camera port was made in the transdiaphragmatic approach and the instrument port was made of ICS 7 and ICS 9. A pre tied loop ligature was placed to performed a caudal lung lobe biopsy and to simulate biopsies of the others lung lobes.

RESULTS

Biopsy of the cranial aspect of the right caudal lung lobe was performed at ICS 9. Simulated biopsy of the accessory lung lobe was performed at ICS 9. Simulated lung biopsy of the right cranial and middle lung lobes was performed at ICS 7. The caudal and dorsal aspect of the right caudal lung lobe was not visualized by telescope at transdiaphragmatic approach, and biopsy was not performed.

CONCLUSIONS

Thoracoscopic transdiaphragmatic approach for lung lobes biopsies was a feasible technique, except for the caudal aspect of the right caudal lung lobe. An ideal intercostal port for biopsy of each right lung lobe was determined.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model

OBJECTIVE

To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies.

STUDY DESIGN

Ex vivo, simple randomized study.

SAMPLE POPULATION

Urinary bladders harvested from canine cadavers (n = 23).

METHODS

Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies.

RESULTS

Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders.

CONCLUSION

Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure.

CLINICAL SIGNIFICANCE

This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Use of a vessel-sealing device versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma

OBJECTIVE

To compare use of a vessel-sealing device (VSD) versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma.

DESIGN

Retrospective cohort study.

ANIMALS

42 client-owned dogs undergoing thyroidectomy because of suspected thyroid carcinoma.

PROCEDURES

Medical records of dogs treated at 4 referral centers from 2010 through 2016 were reviewed, and information was obtained on patient signalment, surgical technique, tumor-specific factors, and operative duration. Postoperative hospitalization time and complications were compared between dogs grouped on the basis of hemostatic technique.

RESULTS

Thyroidectomy was performed with a VSD in 23 dogs and with conventional hemostatic techniques (ie, ligatures, hemoclips, or electrocautery) in 19 dogs. Hemostatic technique (ie, use of a VSD vs conventional hemostatic techniques) was the only factor significantly associated with operative duration (median time, 28 vs 41 minutes). Postoperative hospitalization times and complication rates did not differ between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that use of a VSD, rather than conventional hemostatic techniques, in dogs undergoing thyroidectomy because of suspected thyroid carcinoma resulted in shorter operative times without significantly affecting complication rates or postoperative hospitalization times.

Ex vivo comparison of leakage pressures and leakage location with a novel technique for creation of functional side-to-side canine small intestinal anastomoses

OBJECTIVE

To determine the ability of functional side-to-side small intestinal anastomoses (FSS-SIA) created with an electrothermal bipolar vessel sealing (EBVS) device to resist leakage.

STUDY DESIGN

Experimental, ex vivo.

SAMPLE POPULATION

Jejunal segments (n = 130) from 10 healthy canine cadavers.

METHODS

Four types of anastomoses were created (two segments/construct and 15 constructs/group): EBVS (group A), EBVS + transverse stapling (group B), stapled (group C), and EBVS + suture augmentation (group D). Initial leakage pressure (ILP), initial leakage location (ILL), and maximal intraluminal pressure were compared between groups, and five group A constructs were analyzed histologically.

RESULTS

Initial leakage pressure was greater in group D than in groups A, B, and C (P < .011). There was a difference in ILL among groups (P = .003). Leakage occurred at the side-to-side intestinal anastomosis fusion line in 13 of 15 (87%) constructs for groups A and B and in nine of 15 (60%) constructs for group D. Maximal intraluminal pressure was greater in group C than in groups A, B, and D (P < .004). Histological examination was consistent with collagenous fusion without cavitation defects.

CONCLUSION

Functional side-to-side small intestinal anastomosis was consistently achieved with an EBVS device. Augmentation of EBVS anastomoses with simple interrupted sutures along the anastomotic fusion line increased ILP compared with stapled anastomoses.

CLINICAL SIGNIFICANCE

Despite the success and feasibility of creating an FSS-SIA with an EBVS device, additional in vivo studies are required to determine the effectiveness of intestinal fusion prior to clinical implementation.

Partial cystectomy with a bipolar sealing device in seven dogs with naturally occurring bladder tumors

OBJECTIVE

To describe the use of a bipolar sealing device (BSD) for partial cystectomy in dogs undergoing excision of bladder tumors.

STUDY DESIGN

Multicenter, prospective, clinical pilot study.

SAMPLE POPULATION

Seven client-owned dogs with nontrigonal urinary bladder lesions.

METHODS

Dogs underwent a sealed partial cystectomy with a BSD, with or without cystoscopic guidance of the resection. The sealed cystectomy site was oversewn with a single-layer simple continuous pattern with monofilament absorbable suture.

RESULTS

Sealed partial cystectomy was successfully performed in all dogs, with a median surgical duration of 69 minutes (range, 50-120). Lesions were located at the apex in six dogs and on the ventral midbody of the bladder in one dog. No urine leakage from the BSD luminal seal was visible prior to suture closure in three dogs, while varying amounts of urine leaked from the sealed site in four dogs. Suture was placed over the seal in grossly normal bladder tissue in six dogs and in the BSD peripheral thermal effect zone in one dog; in this latter dog, revision cystorrhaphy was required 3 days later because of uroabdomen. The other six dogs had no clinical evidence of urinary bladder healing complications.

CONCLUSION

The integrity of the seal generated by the BSD tested here on partial cystectomies varied between dogs and was unpredictable.

CLINICAL SIGNIFICANCE

Sealed partial cystectomy with a BSD may reduce exposure of urinary bladder luminal contents to the surgical site. However, the placement of sutures over the seal and through grossly normal bladder tissue is recommended to prevent postoperative uroabdomen.

Influence of use of a bipolar vessel sealing device on short-term postoperative mortality after splenectomy: 203 dogs (2005-2018)

OBJECTIVE

To compare short-term postoperative mortality in dogs after splenectomy performed with or without a bipolar vessel sealing device (BVSD) and to identify variables associated with mortality.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Client-owned dogs (n = 203).

METHODS

Medical records of dogs that underwent splenectomy from 2005-2018 were reviewed. Mortality rates were compared between dogs that underwent splenectomy with or without BVSD. Causes of death and variables associated with short-term mortality were assessed.

RESULTS

Fifteen of 203 (7.4%) dogs died prior to discharge, and seven (3.4%) dogs died prior to suture removal for a total short-term mortality rate of 22 of 203 (10.8%). The estimated difference in proportion of deaths prior to discharge between the BVSD and non-BVSD groups was -0.01 (95% confidence interval = -0.08 to 0.06). Duration of anesthesia was longer when splenectomy was performed without BVSD (median 168 vs 152 minutes; P = .03). Multivariate analysis identified intraoperative (odds ratio [OR] 5.7) or postoperative (OR 13.6) administration of blood products, increasing duration of anesthesia (OR 1.15 per additional 16 minutes), and intraoperative ventricular arrhythmias (OR 6.8) as significantly associated with death prior to discharge. Intraoperative (OR 3.2) or postoperative (OR 7.7) administration of blood products was associated with death prior to suture removal.

CONCLUSION

Use of a BVSD did not appear to increase short-term mortality after splenectomy.

CLINICAL SIGNIFICANCE

Dogs undergoing splenectomy that require intraoperative or postoperative transfusions, experience intraoperative ventricular arrhythmias, or have prolonged anesthesia may be at risk for death in the short-term postoperative period.

Use of Minimally Invasive Surgery in the Diagnosis and Treatment of Cancer in Dogs and Cats

Surgical management of neoplastic disease is common in veterinary medicine. Minimally invasive surgery (MIS) has gained widespread acceptance by veterinary surgeons and is experiencing rapid growth and frequency of use. Many neoplastic diseases in the abdomen and thorax of dogs and cats can be treated as effectively with MIS as with traditional open surgery. Additionally, MIS allows for less invasive options for organ biopsy in cancer patients either for initial diagnosis or for staging to inform prognosis and treatment. Despite the recent increase in MIS, additional research is required to further characterize the benefits to oncology patients and to ensure that surgical oncologic principles and patient outcomes are not compromised by the use of MIS.

Evaluation of a pre-tied ligature loop for canine total lung lobectomy

OBJECTIVE

To determine the ability of a pre-tied ligature loop (PLL) to create a seal against physiological airway pressures after total lung lobectomy and report outcomes in dogs requiring lung lobectomy.

STUDY DESIGN

Ex vivo experimental randomized study and clinical case study.

SAMPLE POPULATION

Thirty cadaveric canine lung lobes and 5 client-owned dogs.

METHODS

Thirty canine lung lobes from dogs weighing 22.5-35 kg were randomized to lobectomy with stapler, PLL, or suture ligation. After lobectomy, each bronchial stump was submerged in water, and the mainstem airway pressure was increased to 80 mm Hg. Leakage was compared between techniques. The PLL was subsequently used in 5 dogs (17-25 kg) with neoplastic disease requiring total lung lobectomy.

RESULTS

Two stapled and 4 sutured bronchial stumps leaked at supraphysiological pressures >15 mm Hg. One stapled bronchial stump failed at a physiological airway pressure (5 mm Hg). None of the PLL lobectomies leaked. The incidence of bronchial stump failures did not differ among techniques (P = .15). Lung lobectomy was performed successfully with the PLL in 5 clinical cases with no intraoperative or postoperative complications; median follow-up time was 6 months.

CONCLUSION

Bronchial ligation with the PLL reliably resisted physiological airway pressures and performed comparably to current standard techniques in cadavers. The PLL provided an adequate air and vascular seal in 5 clinical cases undergoing total lung lobectomy.

CLINICAL RELEVANCE

Pre-tied ligature loops provide an alternative method for total lung lobectomy in dogs.

Use of a novel vessel-sealing device for peripheral lung biopsy and lung lobectomy in a cadaveric model

OBJECTIVE

To evaluate the Caiman vessel-sealing device for peripheral lung biopsy and total lung lobectomy in cadaveric canine lung lobes.

MATERIAL AND METHODS

Twelve lung lobes were randomly assigned to peripheral lung biopsy (n=6) or total lung lobectomy (n=6) with the 12-mm Caiman vessel-sealing device. Lungs were connected to a ventilator set at 10 breaths per minute with an initial pressure of 5 cm H₂ O during the procedure. The lungs were submerged in water for leak testing and the pressure increased until leakage occurred.

RESULTS

Mean airway pressure at which leakage occurred was 39.17 ±13.20 cm H₂ O for peripheral lung biopsies and 38.33 ±13.67 cm H₂ O for total lung lobectomies. None of the samples leaked below 25 cm H₂ O, which is well above the physiologic airway pressure. Histologically, the largest bronchial diameter at the sealed area was 8.84 mm and the extent of collateral damage was approximately 2.7 mm in all specimens.

CLINICAL SIGNIFICANCE

The Caiman vessel-sealing device was successfully used for peripheral lung biopsy and total lung lobectomy in cadaveric canine lung lobes. All sealed lung lobes tolerated supra-physiologic airway pressure, displayed minimal collateral damage, and were of good diagnostic quality. Further experimental studies are needed to evaluate the clinical safety of the device for peripheral lung biopsy or total lung lobectomy.

Complications and Conversion from Endoscopic to Open Surgery

Endoscopic surgery is a rapidly expanding modality of diagnosis and treatment of small animal patients. The development of skills, equipment, and minimally invasive means of correcting complications may be of great importance in decreasing the incidence of conversion from endoscopic to open surgery; however, conversion to an open approach should never be seen as a failure. Conversion should be considered at any time that it is of the greatest benefit for the patient. This concept is important enough to warrant discussion with the owner before surgery and acceptance of the need to convert without further consultation during the procedure.

Current concepts in minimally invasive surgery of the thorax

Thoracoscopy is a technique that has been shown to decrease patient morbidity and is rapidly becoming more diversely applied for diagnostic and therapeutic interventions in veterinary medicine. This article describes the basic equipment and application of thoracoscopy in small animal surgery. The diagnostic and therapeutic applications are introduced and briefly described.

Use of a vessel sealant device for cystic duct ligation in the dog

OBJECTIVE

To compare a vessel sealant device to hemostatic clips for cystic duct ligation in a canine cadaveric model.

STUDY DESIGN

Experimental.

METHODS

Hepatobiliary systems were collected from normal dogs. A microtip pressure transducer was inserted into the common bile duct and a 20-24 g intravenous catheter was placed in a hepatic duct. The cystic duct was ligated with 1 of 3 techniques: vessel sealant device (VSD), 10 mm medium Endoclips™, or 10 mm large Endoclips™ with 6 specimens in each group. Methylene blue was infused until failure, which was recorded as seal/clip failure or retrograde movement of methylene blue into the liver.

RESULTS

Mean failure pressure of the medium endoclip group was significantly lower than the large endoclip group (P = .014). There was no difference between the failure pressure of the VSD group and the medium and large endoclip groups (P = .097, P = .34, respectively). Failure by leakage at the cut surface of the cystic duct occurred in 2 specimens in the medium endoclip group while all others failed by retrograde flow of the methylene blue through the hepatic ducts.

CONCLUSIONS

The vessel sealant device appears comparable to large endoclips for closure of the cystic duct in an acute cadaveric model, while medium endoclips may not fully compress or span the diameter of a cystic duct in large breed dogs and leak at lower pressures.

Bipolar sealing of lung parenchyma: tests in an ex vivo model

BACKGROUND

Almost every pulmonary lobe resection requires cutting the lung parenchyma in the area of a lung fissure. A monopolar cutter or stapler is often used for this purpose. The seal should be absolutely airtight to prevent post-operative pulmonary fistulas. In the present study, the bipolar sealing technique was evaluated regarding air tightness of the seals during normal ventilation and its burst pressure in an ex vivo animal model.

MATERIALS AND METHODS

The investigations were carried out on paracardial lung lobes obtained from heart-lung preparations taken from freshly killed pigs at a slaughter house. In the laboratory, each individual lobe was perfused with Ringer's solution at body temperature and protectively ventilated through a tube (frequency: 20 1/min, p insp = 20 mbar, PEEP +5 mbar). Non-anatomic resection was carried out in the periphery of the lung lobe. The two control groups (12 lobes per group; Group 1-stapler, Group 2-parenchyma suture) were compared to three groups in which different bipolar sealing instruments were used. They were Group 3-MARSEAL(®) 10 mm (KLS Martin, Tuttlingen); Group 4-MARSEAL(®) 5 mm; and Group 5-MARCLAMP(®) (KLS Martin, Tuttlingen). The SealSafe(®) G3 electric current was used in all cases. Ventilation was continued for 20 min following parenchymal resection. Parenchymal sealing was then judged visually in a water bath and given a score (0-3). Burst pressure (mbar) was measured by increasing the inspiration pressure stepwise. Group mean values were compared (nonparametric Mann-Whitney U test, p < 0.005).

RESULTS

Parenchymal seals were airtight under ventilation throughout the observation period in all groups. Mean burst pressures were as follows: Group 1: 47.1 ± 6.2 mbar; Group 2: 32.9 ± 3.9 mbar; Group 3: 38.8 ± 2.2 mbar; Group 4: 25.0 ± 6.4 mbar; and Group 5: 32.9 ± 5.8 mbar. Group 1, the stapler group, thus exhibited the highest burst pressures. Burst pressures for Group 3 were significantly greater than those for Group 2 (p < 0.006). Burst pressures for groups 2 and 5 were similar (p = 0.97). However, the burst pressures for Group 4 were significantly lower than those for Group 2 (p < 0.001).

CONCLUSION

MARSEAL(®) 10 mm and MARCLAMP(®) achieved adequate burst pressures compared to the two control groups and thus might be suitable for clinical use.

The future: taking veterinary laparoscopy to the next level

PRACTICAL RELEVANCE

Laparoscopic surgery minimizes tissue trauma and speeds recovery, but its uptake into veterinary clinical practice has been slow.

CLINICAL CHALLENGES

Laparoscopy is distinctly different from traditional open surgery and a reduced working area and loss of depth perception are among the challenges that the surgeon must get to grips with. Indeed, it is often lack of the necessary skills, rather than the cost of equipment, that presents the greatest obstacle.

AUDIENCE

This article is aimed at practitioners keen to embrace minimally invasive surgery and advises on how to develop excellence in laparoscopic skills. It makes the case for simulation training and outlines methods that can be instituted in practice at low cost and with comparatively little time expenditure. It also describes technological advances that have already increased the success of veterinary 'keyhole' surgery, as well as those that look promising for the future.

EVIDENCE BASE

Simulation training has been an intense area of research and publication within the past 15 years. This article draws on that evidence base and the experience gained by the author and her research team, which is at the forefront of efforts to develop laparoscopic training for veterinarians.