Nonpenetrating clips successfully replacing sutures in base of skull surgery

The surgical management of intraoperative intracranial internal carotid artery injury in open skull base surgery-a systematic review

Intraoperative internal carotid artery (ICA) injury during open skull base surgery is a catastrophic complication. Multiple techniques and management strategies have been reported for endoscopic skull base surgery; however, the literature on managing this complication in open skull base surgery is limited. To perform a systematic review and give an overview of the different techniques described to manage this complication intraoperatively, a systematic review was conducted in PubMed, Ovid Medline, Ovid Embase and Scopus for literature published until July 2021. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full. PRISMA guidelines were strictly adhered to. Out of 4492 articles, only 12 articles could be included, reflecting an underreporting of open skull base ICA injuries. Multiple techniques can be used depending on the location and size of the injury as well as the surgeon's experience. Described techniques include the following: a primary repair via a micro-suture or nonpenetrating clips; wrapping or plugging; coating; occlusion of the parent artery with or without a bypass; packing with further endovascular management. A treatment algorithm is proposed.

Failure Pressures of Dural Repairs in a Porcine Ex Vivo Model: Novel Use of Titanium Clips Versus Tissue Glue

Objective

Endoscopic skull base surgery is advancing, and it is important to have reliable methods to repair the resulting defect. The objective of this study was to determine the failure pressures of 2 commonly used methods to repair large dural defects: collagen matrix underlay with fibrin glue and collagen matrix underlay with polyethylene glue, as well as a novel repair method: fascia lata with nonpenetrating titanium vascular clips.

Methods

The failure pressure of the 3 dural repairs was determined in a closed testing apparatus. Defects in porcine dura were created and collagen matrix grafts were used as an underlay followed by either fibrin glue (FG/CMG) or polyethylene glycol glue (PEG/CMG). A third condition using a segment of fascia lata was positioned flush with the edges of the dural defect and secured with titanium clips (TC/FL). Saline was infused to simulate increasing intracranial pressure (ICP) applied to the undersurface of the grafts until the repairs failed.

Results

The mean failure pressure of the PEG/CMG repair was 34.506 ± 14.822 cm H₂O, FG/CMG was 12.413 ± 5.114 cm H₂O, and TC/FL was 8.330 ± 3.483 cm H₂O. There were statistically significant differences in mean failure pressures among the 3 repair methods.

Conclusion

In this ex vivo model comparing skull base repairs’ ability to withstand cerebrospinal fluid leak, the repairs that utilized PEG/CMG tolerated the greatest amount of pressure and was the only repair that exceeded normal physiologic ICP’s. Repair methods utilizing glues generally tolerated higher pressures compared to the novel repair using clips alone.

Rapid M1 Hemoclips Arteriotomy Repair After Emergency Coil Embolectomy

BACKGROUND

The vascular closure staple clips have been studied in animal models and shown to have comparable results with sutured repair when it comes to the healing process, degree of vessel narrowing, and risk of thrombosis. However, they are clearly superior when the speed of application is taken into account, and they were clinically used in many vascular repair processes. Nevertheless, their usefulness in intracranial vascular surgery has not been described.

OBJECTIVE

To describe the usefulness of hemoclips in fast and efficient repair of medium-sized and large intracranial vessels.

METHODS

Two female patients diagnosed with giant symptomatic cavernous sinus aneurysms were undergoing elective endovascular procedures that were complicated by the dislodgement of coils into the M1 segment of the middle cerebral artery. Both patients were treated performing M1 arteriotomies and coil embolectomy. To avoid prolonged temporary occlusion in the M1 perforator's territory, the arteriotomies were repaired using microhemoclips in less than 10 min with re-establishment of flow.

RESULTS

In both patients, flow was re-established in the M1 segments. In 1 patient, the coils extended to the temporal M2 causing intimal injury and leading to diminished flow. M1 segments in both patients were patent on later angiographic studies.

CONCLUSION

We describe the advantage of emergent cerebrovascular arteriotomy and embolectomy in a rapid repair process that helped avoid massive ischemic injury. We believe this technique should be added to the armamentarium of neurosurgical cerebrovascular options.

Evaluation of Metallic Artifacts Caused by Nonpenetrating Titanium Clips in Postoperative Neuroimaging

BACKGROUND

Nonpenetrating titanium clips create no suture holes and thereby reduce cerebrospinal fluid leakage after dural closure. However, no data exist regarding metallic artifacts caused by these clips during postoperative neuroimaging. We aimed to evaluate clip-related artifacts on postoperative magnetic resonance (MR) images of 17 patients who underwent spinal surgery.

METHODS

A phantom study evaluated the size of metallic artifacts, and a clinical study evaluated the quality of postoperative spinal MR images. Both 1.5-T studies used T1-weighted and T2-weighted fast spin echo sequences. The phantom study compared clip and artifact size for 10 clips. Artifacts were defined as signal voids surrounded by high signal amplitude that followed the clip shape. In the clinical study, 2 neurosurgeons assessed 22 images from 17 patients of the spinal cord, cauda equina, and paravertebral muscles adjacent to the nonpenetrating titanium clips, using 5-point scales.

RESULTS

Mean metallic artifact sizes were 4.82 ± 0.16 mm (T1) and 4.66 ± 0.25 mm (T2; P < 0.001 vs. control). The former and latter were respectively 207% and 200% larger than the clip size. Both readers graded spinal cord and paravertebral muscles images as 3 or 4, indicating very good image quality regardless of clip-related artifacts, with excellent interobserver agreement (κ = 0.99 and 0.98, respectively).

CONCLUSIONS

Metallic artifacts caused by nonpenetrating titanium clips were 200% larger than the actual clip but did not affect spinal cord and extradural tissue visualization. The use of these clips for closing the spinal dura mater does not alter postoperative radiologic evaluation quality.

Economic Impact of the Beneficial Effect of Changing Vascular Anastomotic Technique in Hemodialysis Access

There is an urgent and compelling need to reduce the morbidity and expense of maintaining hemodialysis vascular access patency. We previously reported the beneficial effects of altering anastomotic technique on vascular access patency from a multicenter clinical trial. Interrupted anastomoses created with nonpenetrating clips showed significant improvement in primary, assisted primary, and secondary patencies of native vein fistulae (AVF) and synthetic arteriovenous grafts (AVG). In the current report, we provide an analysis of the economic impact of these procedures. The economic analysis is based on a subgroup of patients who underwent access procedures as outpatients during years 1998–1999 at a university-affiliated hospital that contributed 23% of procedures described in the multicenter clinical trial. Hospital charges and payments received were determined for fistula placement and for commonly performed surgical and endovascular procedures (thrombectomy and angioplasty) that maintain patency. Financial comparisons were based on the hospital's average accumulative charges and actual payments calculated on a daily basis. Cost curves were generated by using charge and payment data. Financial information was extrapolated to the entire study population to estimate the cost savings for the larger group. Both charge and payment calculations indicated financial benefit with the use of clips. When financial estimates were extrapolated to reflect the national volume, clip usage projected significant savings of $20 million for AVF and $30.8 million for AVG for every 1,000 days of access patency. Replacing conventional sutures with clips can reduce the morbidity and cost associated with maintaining permanent hemodialysis vascular accesses. This beneficial effect may be due to the biologic advantages of interrupted, nonpenetrating vascular anastomoses.

Venous Repair with Vascular Clips and Conventional Suture: A Comparative Experimental Study

Objectives:

The non-penetrating Vascular Clip System (VCS) was tested experimentally and compared with the conventional suture method on the venous system.

Materials and Methods:

In five pigs, 30 transverse venotomies were carried out in the jugular and renal veins, and vena cava. Fifteen venotomies were reconstructed using autosuture clips and 15 using the standard needle and suture method. Eight weeks later, following phlebography, the specimens were examined macro- and microscopically.

Results:

For both methods, the veins remained patent; however, significant stenosis of 8.9% (95% CI: 0.6–17.1) for the renal vein and 8.5% (95% CI: 1.2–15.7) for the vena cava occurred when the suture technique was used. The intima to media height ratio remained the same. The anastomosis time with the clips was significantly shorter ( p<0.05), while the endothelium remained intact without any hyperplasia or inflammatory changes, which are usual findings of the suture technique.

Conclusion:

Early and mid-term results show that the VCS clipped anastomotic technique seems to be effective and acceptable for venous reconstructions.

Utility of nonpenetrating titanium clips for dural closure during spinal surgery to prevent postoperative cerebrospinal fluid leakage

OBJECT

The nonpenetrating titanium clip has been successfully used in peripheral arterial bypass surgery. The purpose of this study was to evaluate the leakage pressures and patterns of nonpenetrating titanium clips using a simple model that mimicked spinal surgery. In addition, the authors describe their surgical experience with these clips and the follow-up results in 31 consecutive patients.

METHODS

The authors compared nonpenetrating titanium clips and expanded polytetrafluoroethylene (ePTFE) sutures in relation to the water pressure that could be tolerated by sutured ePTFE sheets, and the leakage pressure patterns were determined. The changes in leakage pressures at 5 minutes, 30 minutes, and 12 hours were examined when the clips and sutures were used in combination with the mesh-and-glue technique in an in vitro study. Thirty-one patients underwent spinal intradural procedures using nonpenetrating titanium clips to suture the dura maters using the meshand-glue technique, involving fibrin glue and polyglycolic acid-fibrin sheets.

RESULTS

A significant difference was apparent between the ePTFE suture group and the nonpenetrating titanium clip group, with the latter showing a leakage pressure that could be sustained and was 1508% higher than that of the former (p = 0.001). In relation to leakage patterns, the nonpenetrating titanium clips did not make any suture holes in the ePTFE sheet and fluid leakage occurred between the clips, whereas fluid leakage was associated with the pressure elevation that occurred at the suture holes made by the ePTFE sutures. Of the 31 patients who underwent spinal intradural procedures using nonpenetrating titanium clips, 1 (3.2%) experienced cerebrospinal fluid (CSF) leakage postoperatively. No other complications-for example, allergic reactions, adhesions, or infections--were encountered.

CONCLUSIONS

The interrupted placement of nonpenetrating titanium clips enables dural closure without creating any holes. These clips facilitate improvements in the initial leakage pressure and reduce postoperative CSF leakage following spinal surgery. The authors conclude that it is very beneficial to suture the spinal dura mater using nonpenetrating titanium clips given the anatomical characteristics of the spinal dura mater and the fact that the clips do not create suture holes.

Dural opening/removal for combined petrosal approach: technical note

Detailed descriptions of stepwise dural opening/removal for combined petrosal approach are presented. Following maximum bone work, the first dural incision was made along the undersurface of the temporal lobe parallel to the superior petrosal sinus. Posterior extension of the dural incision was made in a curved fashion, keeping away from the transverse-sigmoid junction and taking care to preserve the vein of Labbé. A second incision was made perpendicular to the first incision. After sectioning the superior petrosal sinus around the porus trigeminus, the incision was extended toward the posterior fossa dura in the middle fossa region. The tentorium was incised toward the incisura at a point just posterior to the entrance of the trochlear nerve. A third incision was made longitudinally between the superior petrosal sinus and the jugular bulb. A final incision was initiated perpendicular to the third incision in the presigmoid region and extended parallel to the superior petrosal sinus connecting the second incision. The dural complex consisting of the temporal lobe dura, the posterior fossa dura, and the freed tentorium could then be removed. In addition to extensive bone resection, our strategic cranial base dural opening/removal can yield true advantages for the combined petrosal approach.

Primary closure of a cerebrospinal fluid fistula by nonpenetrating titanium clips in endoscopic endonasal transsphenoidal surgery: technical note

Postoperative cerebrospinal fluid (CSF) leakage is one of the most common and aggravating complications in transsphenoidal surgery. Although primary closure of the fistula would be the most desirable solution for an intraoperatively encountered CSF leak, it is difficult to achieve in such a deep and narrow operative field. In this article, the authors report endonasal endoscopic applications of no-penetrating titanium clips to repair a CSF fistula following tumor removal. The AnastoClip Vessel Closure System (VCS; LeMaitre Vascular, Boston, MA) was used for closure of a CSF fistula in endonasal transsphenoidal surgery. In all four patients, CSF leakage was successfully obliterated primarily with two to five clips. There was no postoperative CSF rhinorrhea or complications related to the use of the VCS. Metal artifact by the clips on postoperative images was tolerable. Primary closure of the fistula using the VCS was an effective strategy to prevent postoperative CSF leakage in transsphenoidal surgery. Future application can be expanded to reconstruction of the skull base dura via endonasal skull base approaches.

REPAIR OF AN ALARMING INTRAOPERATIVE INTRACAVERNOUS CAROTID ARTERY TEAR WITH ANASTOCLIPS: TECHNICAL CASE REPORT

OBJECTIVE

Surgical treatment of an intracavernous carotid aneurysm (ICCA) is difficult because of the close relationship to bone, dura, and neurovascular structures. Intraoperative rupture of an ICCA is challenging, especially if the site of rupture is at the base of the aneurysm. We present a case of intraoperative rupture of an ICCA caused by clinoidectomy. We repaired it by using a single-clamp applicator (AnastoClip Vessel Closure System, 1.4 mm; LeMaitre Vascular, Burlington, MA).

CLINICAL PRESENTATION

In April 2007, a 40-year-old woman underwent neurosurgical treatment at another institution for a ruptured basilar bifurcation aneurysm, with good recovery. Digital subtraction angiography performed at this time showed the presence of left internal carotid artery aneurysms, 1 at the anterior wall of the paraclinoidal segment and 1 at the lateral wall of the intracavernous segment. In February 2008, the patient was referred from outside Finland to our department for microsurgical treatment of both aneurysms.

TECHNIQUE

A lateral supraorbital approach was used, and during extradural removal of the anterior clinoid with a rongeur, the ICCA ruptured. The base of the intracavernous aneurysm was involved in the rupture, and we used a single-clamp applicator to repair the internal carotid artery. Intraoperative digital subtraction angiography, indocyanine green video angiography, and Doppler ultrasonography showed a good flow in the artery. The paraclinoid aneurysm was uneventfully clipped during the same intervention.

CONCLUSION

Intraoperative rupture of ICCA was repaired quickly and effectively by using a single-clamp applicator. Our case and experimental data from other microsurgical vascular experiences suggest that the future of intracranial vessel repair/anastomoses will be using microclips and other simpler devices more, allowing the neurosurgeon to perform fast and effective vessel repair.

Trial of new vascular clips for aortic anastomosis in a canine model

OBJECTIVES

We created a new vascular clip designed for aortic surgery. The purposes of this investigation were to examine surgical applicability in a clinically relevant aortic replacement model and to assess biomechanical strength of the clipped anastomosis and serial histologic changes in the clipped anastomotic site.

METHODS

Twenty-one beagles underwent descending thoracic aortic replacement. Distal anastomosis was performed with the new clips, mimicking the cuffed anastomosis technique, and proximal anastomosis was carried out by conventional suture anastomosis. Tissue specimens of the anastomotic sites were harvested at 1, 3, 6, and 12 months postoperatively for examination.

RESULTS

There was no significant difference in the time required to carry out clip anastomosis (12.2 +/- 1.3 minutes) and suture anastomosis (13.7 +/- 0.9 minutes; P = .38). Neither type of anastomotic site was disrupted by raising the intraluminal pressure to 280 mm Hg. Microscopically, the areas of aortic wall compressed by vascular clips appeared as hyalinized areas adjacent to surrounding collagen fibers, with no significant infiltration of inflammatory cells. Identical histologic changes were observed at the site of the sutured anastomosis. The media at the clipped anastomosis site was significantly thinner than that at the sutured anastomosis site at 1 month after the operation. However, there was no significant difference in the thickness of the media at 3 months.

CONCLUSIONS

The new vascular clips were effective in this clinically relevant model, with appropriate biomechanical strength, and the anastomotic sites underwent similar histologic changes to those observed after suture anastomosis.

Five years' world experience with nonpenetrating clips for vascular anastomoses

BACKGROUND

A new sutureless technique has been introduced clinically to facilitate the process of vascular reconstruction and improve patency. The Vessel Closure System (VCS) is nonpenetrating, creates an elastomeric everted anastomosis, and is easily and reproducibly applied. The objective of this report is to review the published world experience that has accrued regarding these clips with attention to the assets, liabilities, and pitfalls associated with the new technology.

DATA SOURCES

Medline search and manual cross-referencing were performed, after which 61 original articles were identified on the use of VCS clips for vascular anastomoses.

RESULTS

Advantages of the clips compared with sutures include the technical ease of application, the reduced anastomotic time, the superior hemodynamics, and the improved healing pattern of the anastomosis. Disadvantages include the potential problems in atherosclerotic vessels, lack of prospective randomized long-term follow-up, and initial costs. The best clinical results have been achieved in microvascular repair, as well as with vascular access and transplantation surgery.

CONCLUSIONS

The VCS clip technology has become an accepted vascular anastomosing technique, which in future could lead to the use of clips as a standard approach and the use of sutures only in case of severe atherosclerosis and other circumstances in which vessel edges are difficult to evert.

Non-penetrating Vascular Clips Anastomosis Inhibited Intimal Thickening Under Poor Runoff Conditions in Canine Autogenous Vein Grafts

OBJECTIVE

Late graft failure is still a significant problem, particularly in cases with poor runoff vessels. The main cause of late graft failure is intimal thickening of the anastomotic region. Vascular closure system (VCS) clips may provide ideal anastomosis, since they do not penetrate the wall. Therefore, we examined whether the VCS clips affect intimal thickening under poor runoff conditions in the canine autogenous vein grafts.

METHODS

A canine poor runoff model was prepared at both femoral veins. Four weeks after the first surgical procedure, two groups were established according to the two different methods of anastomosis employed. The right femoral vein graft was performed using polypropylene sutures, conventional surgical anastomosis (control group), while the left femoral vein graft was performed using VCS clips anastomosis (VCS group). Four weeks after grafting, the vein grafts were removed and the intimal thickening of proximal, distal anastomosis and midportion of the vein grafts were examined histologically.

RESULTS

In the control group, flow rate and variation were 26+/-8 ml/min and 51+/-10 dynes/cm(2), respectively. In the VCS group, the flow rate and variation were 23+/-11 ml/min and 44+/-14 dynes/cm(2), respectively. There were no significant differences between the two groups. The average value of intimal thickening of both the anastomotic region and the midportion of the vein graft in the VCS group was significantly inhibited compared to that of the control group. The number of positive cells of masson trichrome stain in the VCS group was significantly less than that of the control group.

CONCLUSIONS

These experiments indicate that VCS clips significantly inhibit intimal thickening under poor runoff conditions in canine autogenous vein grafts to a greater extent compared to suture-constructed anastomosis. One mechanism that may account for the decreased intimal thickening is the inhibition of the expression of transforming growth factor-beta (TGF-beta), because the number of positive cells of masson trichrome stain in the VCS group was significantly less than that of the control group.

Patency and flow characteristics using stapled vascular anastomoses in dialysis grafts

BACKGROUND

Improving patency of hemodialysis grafts is challenging. Vascular stapling creates nonpenetrating anastomoses, possibly decreasing intimal hyperplasia. We investigated patency and flow characteristics of stapled hemodialysis grafts.

METHODS

Eighty-six grafts (41 stapled, 45 sewn) were placed in 84 patients (prospective, randomized). The groups had comparable demographics.

RESULTS

Thirty-six grafts were functioning at the study endpoint. Complications in both groups were similar. The primary patency (stapled, 342 days versus sewn, 382 days; P = 0.67) and secondary patency (stapled, 513 days versus sewn, 507 days; P = 0.76) had no significant differences. Flow characteristics were similar between the groups. Thrombectomies per patient-year were 1.01 for stapled grafts and 1.12 for sewn grafts (not significant). Stapling decreased the average operating time by 4.5 minutes.

CONCLUSIONS

Stapled and sewn anastomoses have similar primary and secondary patency and flow characteristics, with minimal operative time differences. Stapled anastomoses are safe but had no advantage over sewn anastomoses in this study.

Dural closure with nonpenetrating clips prevents meningoneural adhesions: an experimental study in dogs

OBJECTIVE

Meningospinal and cranial dural adhesions were compared in a canine model, after duraplasty using nonpenetrating clips or penetrating needles and sutures.

METHODS

Fourteen dogs underwent bilateral craniotomies and duraplasties, with implantation of dural prostheses (DuraGuard; Biovascular Corp., Minneapolis, MN), using either 6-0 silk sutures or titanium clips (DuraClose; Surgical Dynamics, Norwalk, CT). Fourteen other dogs underwent L3-L4 laminectomies; three longitudinal dural incisions were closed with 6-0 silk sutures, 6-0 polyglactin 910 (Vicryl) sutures, or clips. Groups of eight dogs (four cranially treated and four spinally treated) were killed 6, 12, 24, and 52 weeks after surgery, and specimens were collected for study after perfusion and fixation (two cranial and two spinal dural reconstructions at 52 wk). Evaluations included assessment of the appearance of approximated dural margins and responses to clips, sutures, and dural prostheses (inflammation, foreign body reaction, fibrosis, and severity of meningospinal/meningocerebral adhesions). Data were evaluated using the Wilcoxon signed-rank and McNemar tests.

RESULTS

Duraplasties with clips displayed significantly less extensive acute and chronic inflammation, foreign body reaction, and meningoneural adhesions than did repairs with needles and sutures.

CONCLUSION

This report is the first long-term experimental study comparing two fundamentally different methods for dural repair in a relevant animal model.

Preliminary prospective randomized experience with vascular clips in the creation of arteriovenous fistulae for hemodialysis

BACKGROUND

A new vascular clipping system (VCS) has been introduced for clinical use. This study was developed to determine whether patency rates and treatment outcomes for anastomoses in hemodialysis access surgery can be improved by the application of this new technology.

METHODS

During a 10-month period, 96 consecutive patients requiring autologous fistula, synthetic fistula, or graft revisions for hemodialysis were prospectively randomized into two treatment groups. Anastomoses were constructed with the VCS in 46 patients and with polytetrafluoroethylene (PTFE) suturing in 49 patients. The procedures were performed in an outpatient setting, at a large medical center, by one surgeon. Time to construct the anastomosis, amount of bleeding from the anastomotic site, and primary and secondary graft patencies were analyzed.

RESULTS

The mean time to construct anastomoses in autologous and synthetic grafts using VCS clips was significantly shorter than with sutures (autologous 14 versus 22 minutes, P = 0.0001; and new grafts 26 versus 30 minutes, P = 0.04). Blood loss was less in anastomoses done with the VCS clip; however, statistical significance was reached only for autologous fistulas (P = 0.0001). At 2-year follow-up, primary and secondary patencies were similar for both the VCS and suture groups with the exception that a statistically significant improvement was found in secondary patency for autologous fistulas when performed with the VCS.

CONCLUSIONS

The VCS clip is easy to use and produces a more rapid anastomosis with less bleeding. Primary and secondary patencies using the VCS clip were equivalent or improved when compared with standard suture. In our experience, no complications have been attributed to the use of the clip technique.

Carotid arteriotomy closure using a vascular clip system

PURPOSE

To compare a newly released vascular clip system (Vascular Clip-applier System; Auto Suture Company, Norwalk, CT) designed for sutureless vessel closures and anastomoses with standard suture closure of carotid arteriotomies after carotid endarterectomies.

PATIENTS AND METHODS

Sixteen consecutive patients with symptomatic and severe carotid stenoses were randomly allocated to receive either standard suture (running 6-0 monofilament) or clip artery closures after undergoing carotid endarterectomies. The speed of arteriotomy closure was calculated for each procedure, and hemostasis, complications, and postoperative carotid patency were determined and recorded for each patient.

RESULTS

The clip applier system performed well, and arteriotomy closure with clips was significantly faster than suture closure (0.36 cm/min in the sutured group versus 0.52 cm/min in the clipped group, P = 0.019). Carotid patency assessed by ultrasonography 4 to 8 weeks after surgery showed that all arteries in both groups were patent. Two hemostasis problems occurred in the clip closure group, one minor that was caused by the use of incorrect clip size and one major that was probably caused by a combination of sudden arterial hypertension and clip failure. This complication resulted in a large neck hematoma and cross-clamp ischemia during the ensuing suture repair of the arterial dehiscence.

CONCLUSIONS

As a result of this small study, we determined that clip closure of carotid arteriotomies was feasible, but it remains questionable whether the increased speed of a sutureless closure is clinically important for this procedure. Concerns regarding the strength of clip closure of an endarterectomized vessel and the cost of clip closure compared with standard suture techniques suggest that there may be no clinically significant benefits of arterial clip closure over suture closure after carotid endarterectomy, and there is potentially some risk.

Experimental evaluation and clinical use in the head and neck of a 3M/Precise microvascular anastomotic device

Microvascular reconstructions in the head and neck are usually long operating time procedures. Mechanical anastomotic devices help to reduce operating time and can reduce anastomotic failures avoiding foreign bodies in the lumen of the vessel. One of these systems is the 3M/Precise microvascular anastomotic device, it is a non-absorbable device, however, criticisms of this system have been directed to the fact that pulsation of the vessel wall against a rigid structure could lead to thinning of the vessel wall and aneurysm formation. No aneurysms have been found previously in other experimental models. Our experimental study on the aorta and vena cava of the rat comprises 25 arterial and 25 venous anastomoses. In the arteries, four proximal aneurysms were found, two of these were failures. In the venous anastomoses, no failures were found nor aneurysm formation. The system is very useful for performing clinical end to end venous anastomosis helping to reduce anastomotic failures. Aneurysms have been found in arteries although four different ring sizes were available. The device is less easy to use in them than in veins and sometimes can be difficult to apply, making manual suturing a better choice for clinical arterial anastomosis.

Nonpenetrating, arcuate-legged clip reconstruction of the rat uterine horn

A new method for reconstructing rat uterine horn was developed in which nonpenetrating, arcuate-legged clips are applied in interrupted fashion to everted seromuscular edges, forming an elastomeric flanged joint. This anastomosis has unusual physical and morphologic properties, with improved tissue healing and luminal restitution. Clipping is easier than suturing, and resulted in equivalent fertility rate (50-60%) and litter size. It also is associated with less granuloma formation and hystiocytic infiltration than suture. The new technique has the potential of endoscopic translation for human tubal reconstruction.