Biomedical subjects

W M Kirsch

Publications and source records attributed to W M Kirsch.

At least 19 recordsLinked to original sources

PubMed2001

Sutureless vascular anastomosis: the VCS clip.

Non-penetrating, arcuate-legged clips facilitate vascular reconstructions and significantly reduce the incidence of anastomotic neointimal hyperplasia. Though originally developed as a microvascular-approximating instrument, by far the largest application has been for hemodialysis vascular access. Long-term studies comparing suture to clip for access creation have demonstrated the clear technical and biological superiority of the clip for this procedure. This "sutureless" vascular anastomotic technique is more demanding than conventional suturing, requiring precise vessel preparation and supervised training.

Anastomosis, Surgical↗

PubMed2001

The utility of the VCS clip for creation of vascular access for hemodialysis: long-term results and intraoperative benefits.

UNLABELLED: The purpose of this study was to compare the effectiveness of the VCS vascular clip approximating system for the creation of hemodialysis access fistulas. 173 new vascular accesses were created, 92 prosthetic grafts and 81 autologous fistulas over a 40-month period. 50 sutured and 42 clipped fistulas comprised the prosthetic graft series, and 33 sutured and 48 clipped cases the autologous series. Risk factors associated with access patency were correlated and the primary patencies compared in the suture versus clipped group. A significant improvement in primary patency was noted for the clipped prosthetic group at all time points studied, with a positive trend also noted for clipped autologous fistulae. CONCLUSIONS: The vascular clipping system (the VCS system) provides both long-term and immediate advantages for vascular access construction. Clips have been used successfully to treat seven consecutive patients with upper extremity arterial steal syndrome without the technical difficulties associated with traditional methods of repair.

Adult↗

PubMed2001

An alternative system for cerebrovascular reconstructions: non-penetrating arcuate-legged clips.

Non-penetrating, arcuate-legged titanium clips (VCS) have been utilized successfully over the past five years for a variety of cerebrovascular reconstructions. These applications, including both micro and macrovascular reconstructions, their clinical outcomes and technical considerations are described. Applications include patch angioplasty of cervical carotid endarterectomies, superficial temporal to middle cerebral artery 'bypass' procedures, Takayasu's arteritis and cavernous carotid reconstructions. The non-penetrating clip has proven to be a safe and reliable alternative to suture for these demanding reconstructions. Clips provide the advantages of improved anastomotic compliance, reduced operative time, and reduced incidence of post-operative anastomotic intimal hyperplasia and stenosis. Clip related pitfalls are discussed with recommendations regarding usage.

Anastomosis, Surgical↗

PubMed2001

Impact of nonpenetrating clips on intimal hyperplasia of vascular anastomoses.

Non-penetrating, arcuate-legged titanium clips create an interrupted, non-penetrated, yet compliant vascular anastomoses that is associated with significantly reduced anastomotic neointimal hyperplasia. Recent experimental and clinical studies provide evidence that the non-suture alternative changes the biology of vessel-to-vessel and graft-to-vessel connections that reduces the stimulus for hyperplasia at a number of critical points in the response to injury schema. The compliant, "blood-tight" characteristics of clipped vascular reconstructions are associated with no endothelial injury or intraluminal foreign body, minimal platelet aggregation and laminal flow. Clinical applications including vascular access, femoropopliteal bypass, and closure of carotid endarterectomies are remarkable for the absence of restenosis and preserved anastomotic patency.

Anastomosis, Surgical↗

PubMed1999

Endoscopic intrauterine surgery in primates: overcoming technical obstacles.

Current protocols for fetal surgery require cesarean section and partial fetal extraction, both of which impart significant risks to the mother and fetus. Endoscopic fetal surgery is less invasive and will likely reduce some of these risks, but the technical difficulties and feasibility in a primate model have yet to be explored fully. Four pregnant baboons (95 days gestation) were anesthetized, their uteruses exposed via an abdominal incision, and blunt-tipped flanged endoscopic ports inserted. Amniotic fluid was removed, and warmed saline was infused to dilate the uterus. To evaluate instrumentation and wound closure, the tip of the snout was externalized and bilateral cleft lip-like defects made. The lips were then endoscopically repaired by suture (Endostitch, U.S. Surgical) or unique nonpenetrating clips (VCS, U.S. Surgical). The saline was then removed, amniotic fluid returned, and the ports carefully removed. After 4 weeks, the fetuses were delivered and evaluated. Eight cleft lip-like defects were successfully repaired in all four cases. Operative time averaged 83 min. No infections, amniotic leaks, or adhesions developed. Survival was 50% with two fetuses delivering within 48 hours postoperatively: one from preterm labor, the other with fetal demise from retroperitoneal hemorrhage after operative blunt abdominal trauma. We demonstrate the feasibility of endoscopic fetal surgery in primates. The use of blunt-tipped flanged ports provides a fluid tight seal and allows appropriate closure of the fetal membranes, but requires laparotomy and uterine exposure. Distension of the uterus with warmed saline affords a larger operating field, enhancing visualization and instrumentation of the fetus. Grasping the fetus through the exposed uterus gives excellent control for repair. However, such control is also needed in a percutaneous approach. Further instrumentation development is needed to accomplish similar control for the percutaneous approach.

Animals↗

PubMed1999

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.

Animals↗

PubMed1998

Facilitated vascular anastomoses: the one-shot device.

BACKGROUND: A mechanical system for facilitating vascular anastomosis (end-to-side, end-to-end) is described that enables the rapid construction of nonpenetrated, compliant junctions. The instrument (United States Surgical One-Shot system) simultaneously applies either 10 or 12 nonpenetrating, arcuate-legged titanium clips to everted vessel or prosthetic conduit edges. METHODS AND RESULTS: The instrument has been tested in animals (jugular and femoral vein jump grafts in carotid and femoral arteries, interpositional grafts, 20 pigs) and human cadaveric constructs (saphenous veins to left anterior descending coronary arteries, 20 cases, 5 brachiocephalic access fistulas) as end-to-side constructs. Clipped constructs have equivalent or superior physical properties to control sutured constructs (6-0 polypropylene) as gauged by burst and tensile strength. All studies were performed under Food and Drug Administration Good Laboratory Practice standards, and the device has been approved for marketing by the Food and Drug Administration. CONCLUSIONS: The device enables rapid and reproducible vascular anastomotic constructs with vessels as small as 1.8 mm outer diameter. The constructs are flanged, interrupted, and nonpenetrated.

Anastomosis, Surgical↗

PubMed1998

Endoscopic excision and repair of simulated bilateral cleft lips in fetal lambs.

The use of nonpenetrating clips to accomplish wound closure as an alternative to suture in the repair of simulated cleft lips in partially exteriorized fetuses has been described previously. In this study, the fetus is approached endoscopically, and clipped (n = 8) and sutured (n = 4) intrauterine endoscopic repairs in six lambs (90- to 95-day gestation) are compared. Also used was a newly developed harmonic scalpel to create the defects in the fluid environment. Clipped repairs were nearly 10 times faster than sutured repairs (2.7 +/- 0.5 minutes compared with 24 +/- 4 minutes, respectively). Furthermore, suture incited foreign body inflammation, recruited monocytic inflammatory cells, and exhibited notable scarring. The comparison between clipped and sutured repairs extends the previous observations to the realm of endoscopy and reinforces the previous conclusions of this group that the nonpenetrating clip is more rapid and incites less inflammation than suture in fetal wound approximation and repair.

Animals↗

PubMed1996

A comparative study of apoptosis and cell proliferation in infantile and adult fibrosarcomas.

The infantile fibrosarcoma, a rare tumor phenotypically similar to the adult fibrosarcoma, frequently has a benign course marked by spontaneous regression. Because biologic mechanisms responsible for this regression remain unexplained, an investigation of the role of apoptotic cell death is warranted. The rate of apoptotic cell death has been compared in five cases each of infantile and adult fibrosarcoma by quantitative estimation of in situ DNA double strand breaks. Although positively stained apoptotic cells are evident in all 10 cases, the apoptotic index is significantly higher in infantile cases (mean 6.6% +/- 0.80) compared to adult cases (mean 0.5% +/- 0.08). The proliferative (MIB-1) index of each specimen has been calculated by immunostaining for cell cycle phase-dependent Ki-67 antigen with MIB-1 antibody. Infantile cases have a significantly lower proliferative (MIB-1) index (mean 0.4 +/- 0.15) than adult counterparts (mean 15.9 +/- 3.76). The relatively benign course of the infantile fibrosarcoma may be due to two factors--a significantly lower proliferative (MIB-1) index coupled with enhanced apoptosis.

Adult↗

PubMed1995

Biodistribution and radioimmunopharmacokinetics of 131I-Ama monoclonal antibody in atherosclerotic rabbits.

Monoclonal antibodies have been raised against Ama isolated from human and experimental atherosclerotic plaque. 131I-Ama-MoAb in the whole antibody form was injected into normal NZW rabbits and Watanabe hyperlipidemic rabbits. Biodistribution studies showed that atheromatous aortas had a significantly higher (5-7X) uptake of 131I-Ama-MoAb than that of normal aortas. However, 131I-Ama-MoAb was cleared very slowly from atherosclerotic rabbits. As a result, atheromas could not be identified by imaging because of the low target to non-target ratios.

Animals↗

PubMed1995

Intra-uterine and juxtanatal repair of syndactyly in foetal mice.

39 foetal mice with genetic syndactyly were identified in utero at 17 days of gestation, and the right hindfoot extruded through the uterus. The syndactylous digits were separated by simple incisions. In one group (n = 25) digit separation was maintained during wound healing by the interdigital application of a silver microclip. Digit separation was also assessed in a second group of newborn mice less than 24 hours old (juxtanatal population, n = 24). Two foetuses (5%) and six newborns (25%) developed digital necrosis following microclip application. In the remaining microclipped animals (23 intrauterine and 10 juxtanatal), microclip application maintained digit separation, allowing wound healing to occur with epithelialization of the separated digits. No inflammation or scar formation occurred. In the third group (n = 22) without microclip application, the digital skin reapproximated and webbing recurred during wound healing. These studies demonstrate the need to maintain digit separation during wound healing following intra-uterine or juxtanatal syndactyly repair.

Animals↗

PubMed1995

Intrauterine repair of surgically created defects in mice (lip incision model) with a microclip: preamble to endoscopic intrauterine surgery.

We compared the difference between a nonpenetrating silver microclip and suture on wound healing, inflammatory response, and application time in the repair of surgically created standardized unilateral cleft lip type defects in fetal mice. Excellent lip continuity and dermal reconstitution were achieved by both methods of repair. Furthermore, collagen accumulation did not occur. Occasional mononuclear cells were seen around sutured repairs in contrast to microclipped repairs. The most significant difference, however, was in application time with the microclip requiring an average of 7 seconds (+/- 2) compared to 90 seconds (+/- 15) for suture. We conclude that the microclip offers distinct advantages for intrauterine cleft lip repair: (1) nonpenetrating tissue approximation; (2) less inflammatory response than suture; (3) technically more rapid and less difficult to apply than suture; and (4) can be utilized more readily than suture for endoscopic approaches limiting the risks of fetal surgery for both the mother and the fetus.

Animals↗

PubMed1994

A new concept for anastomosis of the fallopian tube: tissue reconstruction with nonpenetrating, arcuate, legged clips in the rat model.

OBJECTIVE: To evaluate the titanium Kirsch-Zhu microclip microsurgical reanastomoses of the fallopian tubes. DESIGN: Compare the reanastomoses of the rat uterine horn between Kirsch-Zhu clips (Cushman Engineering, Albuquerque, NM) (group A) and conventional suture microsurgical techniques (group B). SETTING: Microsurgery Research Laboratory, Loma Linda University Medical Center, Loma Linda, California. PATIENTS, PARTICIPANTS: Fifteen SD rats Harlan (Harlan Sprague-Dawley Corp., Indianapolis, IN) were done in groups A and B and six in control group (C). MAIN OUTCOME MEASURE: Pregnancy rate, litter size, tissue of procedure, and histologic results. RESULTS: The clip technique was shorter in procedure time and resulted in equal fertility rate and litter size. Histologically, there were less granulomatous formation and histiocytic inflammation, but muscularis thinning and fibrosis were noted with the clip. CONCLUSIONS: The Kirsch-Zhu clip has potential for application to human fallopian tube reanastomoses.

Anastomosis, Surgical↗

PubMed1994

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.

Anastomosis, Surgical↗

PubMed1993

Nonpenetrating clips successfully replacing sutures in base of skull surgery.

Reconstructive challenges engendered by skull base surgery are critical determinants of outcome. A novel nonpenetrating, arcuate-legged clip has proven to be both technically and biologically effective for management of these difficult closures. Clips have facilitated reconstructions associated with the surgical management of eight skull base cases: leiomyosarcoma of the orbit, middle fossa, ptyergopalatine fossa, two meningiomas (petrotentorial, cavernous sinus), vagus nerve paraganglioma, complex traumatic orbital dural tear, and one basilar and two vertebral artery aneurysms.

Journal Article↗

PubMed1992

Detection and possible origins of aminomalonic acid in protein hydrolysates.

Aminomalonic acid (Ama) was first detected in alkaline hydrolysates of proteins in 1984. In this work we describe our search for the origin of aminomalonic acid in alkaline hydrolysates of proteins. We have developed a technique for quantitation of aminomalonic acid based upon gas chromatography/mass spectrometry. Using this technique, we find approximately 0.3 Ama/1000 amino acids in hydrolysates of Escherichia coli protein. We have demonstrated that Ama is not formed from any of the 20 major amino acids during the hydrolysis procedure. Furthermore, the amount of Ama found does not depend on the presence of small amounts of O2 during the hydrolysis. Thus far, we have not been able to demonstrate an artifactual origin for Ama. The results described above suggest that Ama may indeed be a constituent of proteins before the hydrolysis procedure. Possible origins of Ama include errors in protein synthesis and oxidative damage to amino acid residues in proteins.

Amino Acid Sequence↗

PubMed1992

Dilatation in anastomosed arteries can be an artifact of explantation.

Fusiform dilation of the anastomotic site was found at explantation in the majority of rabbit femoral arteries anastomosed with newly developed microclips. This observation was also noted at sutured anastomoses. The mechanism responsible for this morphologic finding was studied by the following experiments: 1) measuring and explanting anastomosed arteries relaxed with 20% lidocaine, 2) latex casts of microclipped arteries, 3) comparing angiographic and histologic morphometric data, and 4) examining synthetic vascular graft anastomoses with identical dilatation. The observations demonstrate that trauma associated with explantation (direct dissection and fixative perfusion) leads to arterial vasoconstriction, but focal medial damage at the anastomotic site prevents constriction at this site.

Anastomosis, Surgical↗

PubMed1992

Sutureless vasovasostomy: new technique using experimental microclip in rat model.

Standard microscopic suture vasovasostomy represents a challenge to many urologists. It is technically demanding, and requires two to five hours of operative time. In an attempt to decrease the technical demand and the time requirement, we report the use of a microvascular anastomotic clip and compare this microclip to a standard eight-suture nonstented technique and a six-suture stented technique using a hollow, absorbable 0.5-mm polyglycolic acid stent. The control group with suture required an average of 38.5 minutes per anastomosis for the nonstented group and twenty-two minutes for the stented group. The clip group required 7.6 minutes for the unstented vasovasostomy and 6.5 minutes for the stented vasovasostomy. We obtained a 91 percent patency rate for the stented clip group and 100 percent patency for the unstented clip group. In a rat vasovasostomy, the operative time as well as the inherent technical demand were significantly reduced.

Animals↗