A Method for Accurately Orienting Microsurgical Blood Vessel Specimens for Longitudinal Sectioning

In a microsurgical study currently in progress, the need arose to prepare accurately oriented longitudinal sections of artery 1 mm in external diameter. The specimens were rats' common femoral arteries which had been subjected to division and microsuture anastomosis. We wanted to see the extent of any narrowing at the site of the microsurgical repair or histological changes on either side of the repair, and to relate such changes to possible causes of surgical trauma.     

Microsurgical hypospadias repair

Successful primary hypospadias repair depends on careful execution of surgical principles, particularly during the urethroplasty portion of the procedure. These principles include careful tissue handling, development of well-vascularized flaps, and avoidance of placing sutures in the uroepithelial surface. Despite meticulous repair, the complication rate requiring secondary surgery is 15 to 30 percent. For the past year, the authors have utilized an operating room microscope, microsurgical instruments, a specially designed microsuture, and a Biooclusive dressing to decrease the postoperative morbidity and subsequent complications requiring secondary surgery (6.5 percent). A comparison of 50 hypospadias patients on whom no microsurgical repair had been used was made with 62 patients on whom microsurgical techniques were employed. The nonmicrosurgical group had 17 complications, 12 of which required reoperation (24 percent). The microsurgical group had 8 complications, 4 of which required reoperation (6.5 percent).     

Morphological evaluation of reconstructive operations on the bronchi using a microsurgical technic in an experiment

Morphological study of bronchial anastomoses repair made with or without microsurgical techniques has been performed in 30 mongrel dogs. Comparative analysis of bronchoscopy, microscopy and scanning electronic microscopy data shows earlier epithelialization, more regular conjunction of bronchial tube and less marked inflammation in anastomosis made with microsurgical techniques. The fact may be explained by a less pronounced traumatization of bronchial tissues with microinstruments and also by tight suture of mucosal layer which creates favourable conditions for repair of anastomosis per primam.     

Early experience with computed tomographic angiography in microsurgical reconstruction

Preoperative angiography is frequently used in the planning of microsurgical reconstruction. However, several potentially devastating complications can result from angiography, including arterial occlusion and pseudoaneurysm. Computed tomographic angiography is a relatively new technique that can provide detailed information about vascular anatomy as well as soft and bony tissue without the risks of traditional angiography. In addition, three-dimensional image reconstruction uniquely demonstrates anatomical relationships among blood vessels, bones, and soft tissue. Fourteen computed tomographic angiograms were obtained in 10 patients undergoing microsurgical reconstruction of the head and neck, lower extremity, or upper extremity. The average patient age was 46.9 years (range, 22 to 67 years). Charges related to the computed tomographic procedure were compared with those of conventional preoperative imaging for microsurgical repair. At our institution, the average computed tomographic angiogram charge was 1140 US dollars, whereas the average charge for traditional arteriography was 3900 US dollars. When compared with intraoperative evaluation, computed tomographic angiograms demonstrated clinically relevant surgical anatomy. No complications were noted for the radiographic procedure or after free flap reconstruction. Computed tomographic angiography provides high-resolution, three-dimensional arterial, venous, and soft-tissue imaging without the risks of traditional angiogram and at a lower cost.     

显微手术治疗正中神经开放性损伤的临床效果分析

目的:分析显微手术治疗正中神经开放性损伤的临床效果。方法:选取2010年2月-2014年3月入住我院接受治疗的120例正中神经开放性损伤患者,随机分成观察组和对照组,每组60例。对照组行常规的手术治疗,观察组行显微手术进行治疗。术后随访6~48个月,比较两组患者正中神经的运动传导速度(MCV)、感觉传导速(SCV)以及正中神经功能优良率。结果:观察组正中神经功能优良率为93.33%,显著高于对照组70.00%(P0.05);两组患者治疗后正中神经MCV、SCV较治疗前均明显增加(P0.05);治疗后观察组MCV、SCV改善程度显著大于对照组(P0.01)。结论:显微手术治疗正中神经开放性损伤效果显著,为神经损伤修复奠定了理论基础,具有巨大的临床应用价值。     

Increased muscle regeneration after repair of divided motor nerve with neuronotrophic factors containing glue

Neuronotrophic factors (NTFs) directed to spinal cord motor neurons were collected in rats within silicone nerve regeneration chambers according to LONGO et al. (1983b). Unilateral addition of NTFs to the fibrin glue used for the repair of divided sciatic nerves improved locally nerve regeneration without affecting the controlateral side. Nerve regeneration was assessed by weight gain of the reinnervated muscles and by radioactive labelling of the acid-soluble phosphate fractions of both nerve Schwann cells and reinnervated muscle cells. Fast gastrocnemius and slow soleus muscles, the motor nerve of which had been repaired with added NTFs, were significantly heavier (21 and 28%) than their controlateral controls, and the metabolic dedifferentiation attendant on post-division nerve repair was less marked. It is suggested that this experimental nerve regeneration model is suitable to test potential nerve-active agents in vivo, under conditions close to the usual clinical setting, with, as ultimate goal, the improvement of the end-results of microsurgical repair of peripheral nerve in man.     

Combined transplantation of free tissues

Combined transplantation of free tissues is a new microsurgical technique by which, with only one set of vessels supplying blood, two or more free tissues can be transplanted simultaneously. Very large soft-tissue defects that are not amenable to conventional transplantation, or defects of two or more tissues, either similar or different in nature, can be repaired in a one-stage operation. It is accomplished by vascular combination; i.e., by means of anastomosing the corresponding vessels of their pedicle, the free tissues to be transplanted are reconstituted into an assembly with only one common vascular pedicle which is then rejoined to the vessels selected to supply blood to the grafts in the recipient site. From December of 1983 to July of 1985, the author has performed 17 combined free-tissue transplantations of seven different clinical types for microsurgical repair and reconstruction of extremities. All the transplanted parts survived, and the extremities regained very good function. Seven patients are reported individually in the paper, each representing a definite clinical type. The concepts and operative technique introduced and the indications and advantages of the newly designed procedure are discussed.     

Endoscopic creation and repair of fetal cleft lip.

In utero repair of several life-threatening malformations in the human fetus is now a clinical reality, yet fetal surgery still poses significant risks to both the mother and the unborn child. Preterm labor is a major problem and is directly related to the large hysterotomy required for fetal exposure. Endoscopic surgical manipulation of the fetus, through small uterine "ports," solves this problem and may eventually permit fetal intervention for non-life-threatening malformations. In this pilot study we demonstrated the feasibility of performing endoscopic surgery on the fetus in situ. A lip incision was created and repaired using endoscopic microsurgical techniques in midgestation fetal lambs. This represents the first application of this technique for in utero fetal intervention.     

The surgical treatment of brachial plexus injuries in adults

Posttraumatic brachial plexus palsy is a severe injury primarily affecting young individuals at the prime of their life. The devastating neurological dysfunction inflicted in those patients is usually lifelong and creates significant socioeconomic issues. During the past 30 years, the surgical repair of these injuries has become increasingly feasible. At many centers around the world, leading surgeons have introduced new microsurgical techniques and reported a variety of different philosophies for the reconstruction of the plexus. Microneurolysis, nerve grafting, recruitment of intraplexus and extraplexus donors, and local and free-muscle transfers are used to achieve optimal outcomes. However, there is yet no consensus on the priorities and final goals of reconstruction among the various centers.     

Upper extremity microsurgery

Learning objectives: After studying this article, the participant should be able to: 1. Understand the indications for free flap coverage of the upper extremity. 2. Know the advantages and disadvantages of the flaps discussed. 3. Have a basic understanding of the anatomy of the flaps discussed. 4. Have a variety of options for free tissue transfer.The application of microsurgical tissue transfer to reconstruction of the upper extremity allows repair of significant bone and soft-tissue defects. Through the years the approach has changed from one of simply getting the wound covered to primary reconstruction to preserve or regain function. A wide variety of free flaps offers the potential to reconstruct nearly any defect of the arm and hand. Vascularized bone transfer can be utilized to repair large bony defects, while innervated free muscle transfer can replace missing muscle function. The total array of flaps and their indications is beyond the scope of a single discussion, but this article focuses on a few flaps that have found application for coverage and functional restoration in the hand and upper extremity.     

Microsurgical replantation of the amputated nose

A case of successful replantation of the nose is presented. Two arteries and one vein were anastomosed, providing a stable framework for direct revascularization of the amputated nasal segment. This resulted in complete survival of the nose, with an excellent aesthetic result. However, despite successful microsurgical arterial and venous repair, significant postoperative blood loss still occurred as a result of anticoagulation. In cases of the amputation of specialized structures, the improved functional and cosmetic result obtained with replantation must be weighed against the risk of blood-borne disease transmission when postoperative transfusion is required. Recognizing the potential need for postoperative transfusion in these cases is important in allowing the surgeon to exercise appropriate judgment in deciding whether replantation should be performed.     

Strategies for the reduction of live animal use in microsurgical training and education

Education and training in microsurgical techniques have historically relied on the use of live animal models. Due to an increase in the numbers of microsurgical operations in recent times, the number of trainees in this highly-specialised surgical field has continued to grow. However, strict legislation, greater public awareness, and an increasing sensitivity toward the ethical aspects of scientific research and medical education, emphatically demand a significant reduction in the numbers of animals used in surgical and academic education. Hence, a growing number of articles are reporting on the use of alternatives to live animals in microsurgical education and training. In this review, we report on the current trends in the development and use of microsurgical training models, and on their potential to reduce the number of live animals used for this purpose. We also share our experiences in this field, resulting from our performance of numerous microsurgical courses each year, over more than ten years. The porcine heart, in microvascular surgery training, and the fresh chicken leg, in microneurosurgical and microvascular surgery training, are excellent models for the teaching of basic techniques to the microsurgical novice. Depending on the selected level of expertise of the trainee, these alternative models are capable of reducing the numbers of live animals used by 80-100%. For an even more enhanced, "closer-to-real-life" scenario, these non-animated vessels can be perfused by a pulsatile pump. Thus, it is currently possible to provide excellent and in-depth training in microsurgical techniques, even when the number of live animals used is reduced to a minimum. With these new and innovative techniques, trainees are able to learn and prepare themselves for the clinical situation, with the sacrifice of considerably fewer laboratory animals than would have occurred previously.     

Microsurgery in the clinic and laboratory

Laboratory animals have been crucial to the development of modern microsurgical techniques which are now routinely used in many clinical departments worldwide. In return, microsurgical techniques are important in biomedical research as they allow many surgical procedures to be performed on rodents instead of dogs, pigs or primates. This has obvious advantages in terms of low cost, the use statistically valid numbers for comparison and the availability of genetically defined animals which are more likely to give valid answers to immunological questions. Microsurgical reconstruction is important in plastic, orthopaedic, urogenital, vascular and peripheral nerve surgery in man and it is likely that it will become part of every surgeon's training in the near future. In this review, the instrumentation essential to any microsurgical enterprise and the sutures available are described. Basic microsurgical techniques for end-to-end and end-to-side anastomosis of small vessels and for joining peripheral nerves, oviducts and other tubular structures are given in outline. Techniques for transplanting kidney, heart, heart and lung, liver, spleen, pancreas, small bowel, stomach, testicle, ovary and whole joint are only outlined but key references are given. Finally, some of the clinical indications for microsurgical reconstruction are reviewed.     

Changes in DNA repair during aging

DNA is a precious molecule. It encodes vital information about cellular content and function. There are only two copies of each chromosome in the cell, and once the sequence is lost no replacement is possible. The irreplaceable nature of the DNA sets it apart from other cellular molecules, and makes it a critical target for age-related deterioration. To prevent DNA damage cells have evolved elaborate DNA repair machinery. Paradoxically, DNA repair can itself be subject to age-related changes and deterioration. In this review we will discuss the changes in efficiency of mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER) and double-strand break (DSB) repair systems during aging, and potential changes in DSB repair pathway usage that occur with age. Mutations in DNA repair genes and premature aging phenotypes they cause have been reviewed extensively elsewhere, therefore the focus of this review is on the comparison of DNA repair mechanisms in young versus old.     

The Impact of Insurance Status on the Outcomes after Aneurysmal Subarachnoid Hemorrhage

Investigation into the association of insurance status with the outcomes of patients undergoing neurosurgical intervention has been limited: this is the first nationwide study to analyze the impact of primary payer on the outcomes of patients with aneurysmal subarachnoid hemorrhage who underwent endovascular coiling or microsurgical clipping. The Nationwide Inpatient Sample (2001–2010) was utilized to identify patients; those with both an ICD-9 diagnosis codes for subarachnoid hemorrhage and a procedure code for aneurysm repair (either via an endovascular or surgical approach) were included. Hierarchical multivariate regression analyses were utilized to evaluate the impact of primary payer on in-hospital mortality, hospital discharge disposition, and length of hospital stay with hospital as the random effects variable. Models were adjusted for patient age, sex, race, comorbidities, socioeconomic status, hospital region, location (urban versus rural), and teaching status, procedural volume, year of admission, and the proportion of patients who underwent ventriculostomy. Subsequent models were also adjusted for time to aneurysm repair and time to ventriculostomy; subgroup analyses evaluated for those who underwent endovascular and surgical procedures separately. 15,557 hospitalizations were included. In the initial model, the adjusted odds of in-hospital mortality were higher for Medicare (OR 1.23, p<0.001), Medicaid (OR 1.23, p<0.001), and uninsured patients (OR 1.49, p<0.001) compared to those with private insurance. After also adjusting for timing of intervention, Medicaid and uninsured patients had a reduced odds of non-routine discharge (OR 0.75, p<0.001 and OR 0.42, p<0.001) despite longer hospital stays (by 8.35 days, p<0.001 and 2.45 days, p = 0.005). Variations in outcomes by primary payer–including in-hospital post-procedural mortality–were more pronounced for patients of all insurance types who underwent microsurgical clipping. The observed differences by primary payer are likely multifactorial, attributable to varied socioeconomic factors and the complexities of the American healthcare delivery system.     

Significance of venous anastomosis in fingertip replantation

Adequate venous outflow is the most important factor for successful fingertip replantation. The authors have attempted venous anastomosis in all cases of fingertip replantation to overcome postoperative congestion. In this article, the significance of venous repair for fingertip replantation is described from the authors' results of 64 complete fingertip amputations in 55 consecutive patients, which were replanted from January of 1996 to June of 2001. The overall survival rate was 86 percent. Of the 44 replantations in zone I, 37 survived, and the success rate was 84 percent. Of the 20 replantations in zone II, 18 survived, and the success rate was 90 percent. Venous anastomosis was attempted in all cases, but it was possible in 39 zone I and in all zone II replantations. For arterial repair, vein grafts were necessary in 17 of the 44 zone I and in one of the 20 zone II replantations; for venous repair, they were necessary in six zone I replantations and one zone II replantation. Postoperative vascular complications occurred in 15 replantations. There were five cases of arterial thrombosis and 10 cases of venous congestion. Venous congestion occurred in nine zone I and one zone II replantations. In five of these 10 replantations, venous anastomosis was not possible. In another five replantations, venous outflow was established at the time of surgery, but occlusion occurred subsequently. Except for the five failures resulting from arterial thrombosis, successful venous repair was possible in 49 of 59 replantations (83 percent). Despite the demand for skillful microsurgical technique and longer operation time, the authors' results using venous anastomosis in successful fingertip replantations are encouraging. By performing venous anastomosis, external bleeding can be avoided and a higher survival rate can be achieved. Venous anastomosis for fingertip replantation is a reliable and worthwhile procedure.     

The nature and extent of histopathologic injury in human avulsed arteries and veins and in experimentally avulsed monkey arteries

To determine the end point of histopathologic damage in avulsed arteries, the forearm arteries of five monkeys being sacrificed were avulsed longitudinally and samples of proximal and distal arteries prepared for light microscopy and transmission and scanning electron microscopy. A severe and consistent circumferential skip lesion was found on the luminal surface involving the intima and media. In 30 percent of vessels, histopathologic damage extended more than 3.0 cm from the rupture point. Similar circumferential tears occurred on the luminal surface of resected human avulsed arteries collected at the time of replantation surgery. No consistent lesions were noted in resected veins from human avulsed amputations. It is possible that in the human artery (as in the monkey) circumferential lesions frequently extend many centimeters from the rupture point and therefore beyond resection distances. Lesions present in the vessel after resection and microsurgical repair might be the site of thrombosis and subsequent occlusion.     

The effect of ovarian steroid deficiency on regeneration of oviductal mucosa following reconstructive surgery

In patients with distal tubal occlusion a microsurgical oviductal reconstruction is, apart from the in vitro fertilization, the only treatment option. Unfortunately, the results of reconstructive surgery are often unsatisfactory. The effects of sex steroids on the regeneration process after reconstructive surgery have not been well investigated. This study was aimed to evaluate the effect of decreased concentrations of ovarian sex steroids (castration) on regeneration of the oviduct mucosa after the reconstructive surgery of distally occluded oviducts. The study was performed on 32 female rabbits that underwent unilateral oviduct ligature and resection of fimbriae. The occlusion lasted six (group I) or twelve weeks (group II). After this time the animals were re-operated, and allocated into 4 groups: castration with reconstructive surgery (IA, IIA), reconstructive surgery only (IB, IIB). After next six or twelve weeks the fallopian tubes were examined under light, scanning and transmission electron microscopes. An immunohistochemical reaction for Ki-67 proliferative antigen was also performed. Ovarian steroid levels were evaluated by radioimmunoassays. The castrated animals had significantly lower levels of estradiol, progesterone and 17-hydroxyprogesterone than the control groups. Long lasting tubal occlusion caused pronounced histological changes of tubal mucous membrane (group II). In the rabbits with preserved ovaries and twelve-week long oviductal occlusion (group IIB), the regeneration of the distal end and restoration of fimbria were not complete twelve weeks after microsurgical reconstruction. In castrated animals with long-lasting occlusion (group IIA) the destructive changes, found in the mucosa of tubal ampullas of occluded oviducts before reconstruction, were still present and even intensified twelve weeks following reconstructive surgery. The castration hampered proliferation of the mucosa cells, thus no fimbriae were restored. Low levels of ovarian steroids were found to have adverse effect on fallopian tube regeneration following reconstructive surgery. The effect was noted even in cases with minor preoperative fallopian tube damage. Therefore, the treatment of concomitant endometriosis or uterine fibroids with GnRH analogues should not be recommended simultaneously with microsurgical tubal reconstruction.     

Structural changes of the thylakoid membrane network induced by high light stress in plant chloroplasts

Land plants live in a challenging environment dominated by unpredictable changes. A particular problem is fluctuation in sunlight intensity that can cause irreversible damage of components of the photosynthetic apparatus in thylakoid membranes under high light conditions. Although a battery of photoprotective mechanisms minimize damage, photoinhibition of the photosystem II (PSII) complex occurs. Plants have evolved a multi-step PSII repair cycle that allows efficient recovery from photooxidative PSII damage. An important feature of the repair cycle is its subcompartmentalization to stacked grana thylakoids and unstacked thylakoid regions. Thus, understanding the crosstalk between stacked and unstacked thylakoid membranes is essential to understand the PSII repair cycle. This review summarizes recent progress in our understanding of high-light-induced structural changes of the thylakoid membrane system and correlates these changes to the efficiency of the PSII repair cycle. The role of reversible protein phosphorylation for structural alterations is discussed. It turns out that dynamic changes in thylakoid membrane architecture triggered by high light exposure are central for efficient repair of PSII.     

Focus: 50 Years of DNA Repair: The Yale Symposium Reports: Hypoxia and DNA Repair

Hypoxia is a characteristic feature of solid tumors and occurs very early in neoplastic development. Hypoxia transforms cell physiology in multiple ways, with profound changes in cell metabolism, cell growth, susceptibility to apoptosis, induction of angiogenesis, and increased motility. Over the past 20 years, our lab has determined that hypoxia also induces genetic instability. We have conducted a large series of experiments revealing that this instability occurs through the alteration of DNA repair pathways, including nucleotide excision repair, DNA mismatch repair, and homology dependent repair. Our work suggests that hypoxia, as a key component of solid tumors, can drive cancer progression through its impact on genomic integrity. However, the acquired changes in DNA repair that are induced by hypoxia may also render hypoxic cancer cells vulnerable to tailored strategies designed to exploit these changes.