Prefabrication and free transfer of a tissue engineered composite flap - An experimental model in the rat.

BACKGROUND: The technique of flap-prefabrication has been successfully established in tissue engineering: missing intrinsic vascularisation of engineered tissue can be generated in vivo by microsurgical vesselloop construction. It is possible to move engineered tissue into a defect with microsurgery. In the literature, the combination of engineered tissue covered with skin is not widely reported. OBJECTIVE: Aim of this study was to establish a model to investigate scaffold prefabrication with full thickness skin graft coverage with subsequent free tissue transfer. METHODS: 8 Wistar rats were operated in 2 separate steps: 1) after creating an arteriovenous loop with the femoral vessels, a porous scaffold was placed on the loop and covered with an inguinally based skin flap. A control was implanted without loop into the contralateral groin. 2) 6 weeks later the prefabricated composite flaps were microsurgically transferred to the cervical region. Skin-island monitoring was performed with Laser Doppler-scanner after the transfer. RESULTS: Continuous loss of the skin islands was observed within 72 hours. Complications included wound-dehiscence, thrombosis and death from anaesthesia; in spite of consistent loop viability. CONCLUSION: Evaluation showed that modifications are necessary to maintain the skin-island cove.

A Grading Score for Colon Preservation Injury in the Rat.

BACKGROUND: Colon transplantation is rarely performed because of the fear for an advanced ischemic injury that may favor septic complications. Systematic studies on colon preservation are missing. The score used to evaluate the preservation injury of the colon is adapted from that used for the small intestine, despite histological and biological differences between the two organs. We studied sequentially the tissue changes in the rat colon during prolonged cold storage (CS) in histidine-tryptophan-ketoglutarate (HTK) solution and designed a grading score specific for the colon. METHODS: Large bowels of Sprague-Dawley rats (n = 9) were perfused in situ with HTK and stored at 4°C for 6 hours, 12 hours, 18 hours, and 24 hours. Samples from the proximal colon were stained with hematoxylin-eosin and alcian blue. Tight junction protein zonulla occludens (ZO)-1 was also studied. RESULTS: Minimal subepithelial edema (hallmark of small intestinal preservation injury) was observed throughout the 24 hours of CS. The two major changes observed during the colonic CS were progressive submucosal edema and the depletion of Goblet cells (GC). The submucosal edema was absent at 6 hours, started after 12 hours, and become significant (over 50% of the circumference) after 18 hours of CS. Depletion of GC started in the luminal half of the crypts between 12 and 18 hours of CS, and all samples revealed significant GC depletion only after 24 hours. The overall appearance of the mucosa was little affected under the CS, and ZO-1 expression was frequently maintained throughout the first 18 hours. CONCLUSIONS: The colon is more resilient to cold ischemia than the small bowel and maintains its histological epithelial features longer than the small intestine. On the basis of these serial observations, we suggest the following grading score: grade 0: normal mucosa, repleted GC, mucosa adhering to the muscular layer; grade 1: limited submucosal edema, repleted GC; grade 2: limited submucosal edema, GC depletion in the luminal half of the crypts; grade 3: advanced (>50% of circumference) submucosal edema, GC depletion in the luminal half of the crypts; grade 4: advanced mucosal injury (edema, GC depletion, epithelial breakdown).

Optimal Solution Volume for Luminal Preservation: A Preclinical Study in Porcine Intestinal Preservation.

BACKGROUND: Rodent studies suggest that luminal solutions alleviate the mucosal injury and prolong intestinal preservation but concerns exist that excessive volumes of luminal fluid may promote tissue edema. Differences in size, structure, and metabolism between rats and humans require studies in large animals before clinical use. METHODS: Intestinal procurement was performed in 7 pigs. After perfusion with histidine-tryptophan-ketoglutarate (HTK), 40-cm-long segments were cut and filled with 13.5% polyethylene glycol (PEG) 3350 solution as follows: V0 (controls, none), V1 (0.5 mL/cm), V2 (1 mL/cm), V3 (1.5 mL/cm), and V4 (2 mL/cm). Tissue and luminal solutions were sampled after 8, 14, and 24 hours of cold storage (CS). Preservation injury (Chiu score), the apical membrane (ZO-1, brush-border maltase activity), and the electrolyte content in the luminal solution were studied. RESULTS: In control intestines, 8-hour CS in HTK solution resulted in minimal mucosal changes (grade 1) that progressed to significant subepithelial edema (grade 3) by 24 hours. During this time, a gradual loss in ZO-1 was recorded, whereas maltase activity remained unaltered. Moreover, variable degrees of submucosal edema were observed. Luminal introduction of high volumes (2 mL/mL) of PEG solution accelerated the development of the subepithelial edema and submucosal edema, leading to worse histology. However, ZO-1 was preserved better over time than in control intestines (no luminal solution). Maltase activity was reduced in intestines receiving luminal preservation. Luminal sodium content decreased in time and did not differ between groups. CONCLUSIONS: This PEG solution protects the apical membrane and the tight-junction proteins but may favor water absorption and tissue (submucosal) edema, and luminal volumes >2 mL/cm may result in worse intestinal morphology.

Circular anastomotic experimental fibrin sealant protection in deep colorectal anastomosis in pigs in a randomized 9-day survival study.

PURPOSE: The reported rate of clinically apparent anastomotic leakage (AL) in a low anterior resection of the rectum (LAR) (≤7 cm from the anal verge) using a circular double-stapled anastomosis (CDSA) without defunctioning stoma is up to 37.5 %. Since AL may result in life-threatening peritonitis, sepsis, and multiple organ failure, LAR and CDSA are regularly combined with defunctioning stoma. Accordingly, we now evaluated whether LAR and CDSA without defunctioning stoma but with extraluminal anastomotic application of an experimental fibrin sealant reduce the AL rate. This might prevent humans from defunctioning stoma increasing quality of life and decreasing surgical costs. METHODS: Forty 8-week-old pigs underwent LAR and CDSA in an end-to-end technique (descendo-rectostomy). Animals were randomized into a therapy and control group (gr.). The therapy gr. (n = 20) received an additional extraluminal circular application of an experimental fibrin sealant to the anastomosis. The objective was to assess the incidence of clinically apparent and non-clinically apparent leakage through the ninth postoperative day. Double-contrast barium CT radiographs of the colorectal region were performed on the ninth postoperative day or earlier, in case there were clinical signs of AL. All remaining animals were sacrificed on the ninth postoperative day and the anastomotic region was histopathologically analyzed. In case of earlier diagnosed AL, animals were sacrificed immediately. Blood samples were taken for complete blood count, chemistry, and coagulation profile prior to surgery and on the first, third, fifth, seventh, and ninth postoperative day. RESULTS: A circular extraluminal anastomotic application of an experimental fibrin protection decreased the rate of clinically and non-clinically apparent AL from 20 % (n = 4) in the control group to 5 % (n = 1) in the treatment group. Ulcerations were also observed in both gr. (control gr.-5 animals, therapy gr. -3 animals). All animals with AL showed necrosis surrounding the hole at the anastomoses. Three additional animals had a full wall defect at the anastomotic region that was blocked by the experimental fibrin sealant. The fibrin sealant was present at necropsy in all treated animals. CONCLUSION: Circular anastomotic protection with the experimental fibrin sealant blocked anastomotic full wall defects, preventing peritonitis and significantly reducing the AL rate from 25 to 5 %.

Can an adipofascial flap be used to prevent adhesions after plating of the proximal phalanx? A case report.

Tendon adhesions in zone IV after proximal phalangeal fractures are common and may lead to loss of range of motion at the proximal interphalangeal joint. The type of fracture, surgical technique and rehabilitation strategy also influence the final functional outcome. Plate fixation is a reliable solution in cases of comminuted phalangeal fracture. This article describes how adhesions between the plate and extensor apparatus in cases of comminuted fractures of the proximal phalanx can be reduced by using an adipofascial flap.

PREDISPOSANT FACTORS FOR INTIMAL HYPERPLASIA AND THEIR MECHANISMS OF ACTION IN OPEN VASCULAR SURGERY. A REVIEW.

BACKGROUND: Intimal hyperplasia is a multifactorial process that determines local stenosis and subsequent ischemia after revascularisation procedures. It is controlled by a plethora of cytokines, growth factors and proteases that interact through multiple mechanisms, empowering or inhibiting their hyperplasic action. Although the elements involved are the same, the resulted degree of vascular stenosis varies. METHODS: To highlight the predisposing conditions which enhance the vascular response to injury we consulted articles from Pubmed database, searching for the keywords "intimal hyperplasia", "neointimal hyperplasia" and "risk factor". RESULTS: 101 articles were included in the study. Risk factors analyzed are classified into local and systemic and the mechanisms by which they augment the process are explained. CONCLUSION: Knowledge of risk factors and their control when possible is a key element in increasing revascularization patency.

A new anastomotic leakage model in circular double stapled colorectal anastomosis after low anterior rectum resection in pigs.

BACKGROUND: A high incidence of anastomotic leakage (37.5%) is reported after low anterior rectal resection (LAR) and circular double-stapled anastomosis without protective ileostoma. Since the pathomechanism of anastomosis leakage is still unclear, a suitable animal model would be most desirable. METHODS: The objective was to assess the incidence of clinically apparent and inapparent leakage after LAR in pigs (n = 20). Endpoints were radiological, clinical, macroscopic, and histologic proof of anastomotic leakage on the 9th postoperative day. Integrity of anastomosis was assessed by double-contrast barium examination on 9th postoperative day. Animals were sacrificed and anastomoses were resected for histopathological investigation. In case of earlier clinical apparent anastomotic leakage, radiologic double-contrast barium was performed immediately. RESULTS: LAR with a circular double-stapled anastomosis without protective ileostoma was performed in 20 pigs (m:f = 8:12). Length of resection was 10-20 cm, anastomosis was performed 7 cm ab ano. Five animals (25%) developed clinical apparent anastomotic leakage (no appetite, fever, inactivity, tachypnea, discomfort, pain) between the 6th (n = 1) and 9th (n = 4) postoperative day, proven by double-contrast barium radiographs. Additionally in 1 animal clinical inapparent anastomotic insufficiency was observed radiologically. Total rate of leakage was 30% (n = 6). These results were confirmed by leucocytosis, low potassium levels, in two cases high ALT and AST and local peritonitis in all cases. CONCLUSION: Including one additional case of clinical inapparent leakage, total rate of anastomotic leakage was 30% (6/20). Thus we managed to establish a new experimental model of anastomotic leakage after low rectal resection comparable to the human situation.

Arterio-venous fistula using nonpenetrating titanium clips (VCS).

UNLABELLED: Vascular access in haemodialysis is still accompanied by a high morbidity rate. Neointimal hyperplasia due to thrombosis is one of the main causes of vascular access failure. The purpose of this paper is to present the use of non-penetrating titanium clips (VCS) for the creation of an arteriovenous fistula and its outcome. MATERIALS AND METHODS: A male patient, 47 years old, with end-stage renal disease - ESRD - (2005) was addressed to our service, for a vascular access reintervention, after a failed forearm radio-cephalic fistula performed 3 months before. In January 2007, an arteriovenous fistula between the brachial artery and the median cubital vein using non-penetrating titanium clips (Anastoclip VCS) was created. RESULTS: The vascular anastomosis was performed in 17 min. After unclamping the artery, a solid pulse and consistent thrill were obtained at the level of the cubital fossa. The postoperative course was uneventful. The arteriovenous fistula remains functional 60 months post-surgery. CONCLUSIONS: The Anastoclip VCS system is versatile, safe to manipulate and enables fast anastomosis. Arteriovenous anastomosis performed with non-penetrating clips may be a solution with the potential to reduce postoperative complications and extend arteriovenous fistula patency in ESRD.

Meningococcal septic shock after IUD insertion, a case presentation.

Neisseria meningitidis is a normal commensal of human mucous membranes that is no longer considered to be restricted to the nasopharynx. Due to the practice of oral sex, the mucous membranes of the cervix, urethra or anus have become a potential infection site for this bacterium. Inserting an intrauterine device (IUD), can alter the protective barrier of the endocervical mucosa, allowing for bacterial infection and systemic spread. We present a case report of a 40-year-old woman who presented with abdominal pain, spotting and fever after inserting an IUD and developed a fulminant septic shock. Blood cultures and cultures from ascites showed the presence of Neisseria meningitidis group Y. From our knowledge, there are a few cases presented in the literature of toxic shock syndrome after IUD insertion, caused by Staphylococcus aureus or Streptococcus group A, but this is the first case of meningococcal sepsis after IUD insertion described. So, even though IUDs rarely cause significant infection, physicians should consider this device as a possible source in reproductive-age women with the clinical features of sepsis.

Does VEGF have an effect on the survival of a long random skin flap by its application at the recipient area?

BACKGROUND: Vascular endothelial growth factor (VEGF) is a hormone-like molecule which has been shown to act on a specific receptor system and in this way to be the basic regulator of angiogenesis. The effect on the survival of a long random skin flap was examined by exogenous administration of this cytokine, at flap's recipient site. MATERIALS & METHODS: A standard dorsal skin flap measuring 1.5 x 7.5cm was elevated in eighteen wistar rats with the pedicle centered and attached between the lower angles of the scapulae. The length to width ratio was relatively high (5:1). The rats were divided in two groups of nine. In group A, flap was elevated and a skin defect was created next to it. Normal saline was injected into the fascia of the defect and the flap was transposed and secured over the previously created recipient site. In group B, flap was elevated and transposed to a previous created defect, as before, where, this time, injections of VEGF were applied into the fascia of the recipient bed. Seven days later the rats were euthanized and the flaps were excised. The underlying fascias of the recipient beds were also excised in the same dimensions. The specimens were measured, photographed and put into formalin 10%. Immunohistochemical staining and histological analysis followed. RESULTS: The differentiation between the surviving and the necrotic skin was macroscopically clear within seven days time. In group A, the mean flap survival percentage was 36.8%. In group B the percentage was 56.3%, respectively. Neovascularization of the fascia of the recipient bed was also demonstrated when VEGF had been injected. CONCLUSIONS: Exogenous administration of VEGF into the recipient bed of a skin flap improved the survival rate even though the flap's length was relatively high compared to its width.

Infrarenal abdominal aorta approach through median minilaparotomy.

Classically, infrarenal aortic exposure is achieved by xyphopubic or xypho-infraumbilical laparotomy, in transperitoneal approach, or through a left abdominal incision, in retroperitoneal approach. The transperitoneal approach is associated with longer intestinal activity resumption time and incisional hernias on long term, due to intestinal extracavitary mobilization and long incision. These disadvantages disappear in laparoscopic approach, but this method is extremely laborious, requires an extended period for dissection, and elicits increased difficulty in performing the anastomosis on the aorta. The purpose of the study is to evaluate the infrarenal abdominal aorta approach through median minilaparotomy, a method that combines the excellent exposure of xypho-pubic incision with the low morbidity of laparoscopic approach. Between 07.01.2010 - 07.01.2011, we performed 37 revascularization surgeries in 36 patients with aorto-iliac occlusive disease (one patient required reintervention due to graft thrombosis), approaching the infrarenal aorta through median minilaparotomy. The sex distribution was 35 men and one woman. The average age was 61.1 years. There have been 25 aorto-bifemoral bypasses, 11 aorto-unifemoral bypasses, and one aorto-biiliac bypass. The mean aorta clamping time was 15 minutes. Average operating time was 150 minutes. We used 26 bifurcated Dacron prostheses and 11 linear ePTFEprostheses. The average intestinal activity resumption time was 32 hours. All patients included in the study were mobilized 24 hours after surgery. The average length of hospitalization was 7.7 days. 5 patients experienced complications during hospitalization and 3 patients suffered long term complications. Infrarenal abdominal aorta approach through median minilaparotomy is a viable alternative to conventional surgical techniques used in aortoiliac occlusive disease.

[Accessory renal allotransplantation with internal or external urinary drainage. An experimental model in pig]. / Allotransplantarea renala accesorie cu drenaj urinar intern sau extern. Model experimental la porc.

This study describes an experimental model of accessory renal allotransplantation in the big laboratory animal (pig). A total of 24 common-breed pigs were used. All allografts were transplanted in an accessory manner and revascularized at the level of the infrarenal abdominal aorta and inferior vena cava. The urinary drainage was performed either through a nexternal uretheroneostomy at the ipsilateral lumbar region (Group A--n=8) or by internal uretheroneocystostomy (Group B--n=8). All transplants were monitored for 8 days postoperatively using translumbar ultrasound-guided biopsies at 1, 4, 7 days. A total of 16 transplants were performed. 1 ectopic donor kidney was found and transplanted in the same fashion. Mean operative time was 125 minutes, immediate postoperative survival was 100% and at 72 hours, 87.5%. The onset of acute rejection was at day 4, by massive lymphocyte infiltration and was directly correlated with the abrupt decrease of the allograft diuresis in Group A, at day 3. At day 7, the rejection was complete. Both methods of urinary drainage are functional and can be employed. This experimental model is a useful tool for training of the transplant surgeons or for transplantation research. The surgical technique for accessory renal allotransplantation in pig is easy to learn and offers the possibility for allograft monitoring until complete rejection without influencing the receptor health condition.

[The first NOTE (Natural Orifice Translumenal Endoscopic) cholecystectomy in Romania: an experimental model in pig]. / Prima colecistectomie NOTES din România: model experimental.

NOTES (Natural Orifice Translumenal Endoscopic Surgery) represents a very new acquisition in the field of gastrointestinal endoscopy, which uses common flexible endoscopes in order to perform intraperitoneal surgical procedures. This procedure offers a very good visualisation of the peritoneal cavity, as well as the possibility of performing surgical procedures. The aim of the study is to report our experience--the first of its kind in Romania--in performing per os, transgastric procedures, emphasizing the technical challenges and the possible complications associated with this method. This is an experimental study, using pigs (tri-hybrid PIC strain), in which peritoneoscopy and cholecystectomy were performed via a hybrid-NOTES approach (a 5 mm laparoscopic port has been used, placed in the right upper quadrant). The transgastric approach of the peritoneal cavity proved to be easy, allowing simple surgical procedures. The results of the study show the feasibility of the method. During surgery, no serious complications occurred, the minor incidents being managed without conversion to classical or laparoscopic surgery.

[The electroacupuncture in patients recently operated for peripheral arterial disease. A comparative study of the two electrostimulation techniques]. / Electroacupunctura la bolnavii vasculari periferici recent operati. Studiu comparativ a doua tehnici de electrostimulare.

UNLABELLED: Possible hemodynamic effects of electro acupuncture (A), by two electro stimulation techniques, were studied at patients with femuro - popliteal bypass revascularization. MMATERIAL AND METHOD:In a prospective study, we evaluated two EA techniques, by calculating the ankle-brachial index (ABI) and by estimating the pain with Numeric Rating Scale (NRS: 0 - 10). The patients were grouped in lot A (30 patients) and B (50 patients) according with the EA technique used. In both lots were used the same acupuncture points (acupoint): Pc6, P9, St36 and Sp6. These acupoints are adjacent to peripheral nerves median, radial, peroneal and safenous nerve. Needles, after insertion, were kept in place for 30 minutes. The electro stimulation (2 Hz) was only for 2 minutes in the lot A and for 30 minutes in the lot B. RESULTS: The blood pressure data and ABI shows a significant increase of ABI (between 0.033 and 0.052) after EA at 5 minutes in the both lots (p < 0.05). At 30 minutes, ABI is increased in lot B, but in the lot A the ABI is elevated only at the non surgical leg (p < 0.05). The decrease of pain post EA is better in the lot B (NRS: initially 2.48--post EA pain decreased to 1.46 and remained 1.66 at 2 hours; p < 0.001), than lot A. CONCLUSIONS: The electro stimulation of certain acupoints, at the operated peripheral arterial disease patients, interfere with tissular perfusion and increase temporally ABI. The pain is diminished more significantly by the 30 minutes electro stimulating technique.

[Endoscopy-assisted harvesting and free latissimus dorsi muscle flap transfer in reconstructive microsurgery]. / Recoltarea asistata-endoscopic si transferul liber a lamboului muscular de latissimus dorsi în microchirurgia reconstructiva.

Because of their generous dimensions, constant anatomy, great plasticity and well defined vascularization, muscles remain the preferred choice when approaching reconstruction of complex tissue defects resulting after trauma or oncological resections. The latissimus dorsi, represents a widely used flap when performing reconstructive microsurgery using free tissue transfer, but with important postoperative complications like seroma, donor-site hematoma and large scars. Along with the development of video assisted harvesting of muscular free flaps, the minimal invasive approach brings an important decrease of the donor site morbidity, followed by a faster healing. This article presents the case of a patient diagnosed with chronic osteomyelitis fistula, on the site of an older posttraumatic fracture at the level of the tibial diaphysis, where a large debridement of soft tissues and the involved bone was performed, followed by microsurgical reconstruction of the left over defect, using a free latissimus dorsi muscular flap harvested by endoscopic-assisted technique.

[Experimental model of pancreas transplantation with portal or systemic drainage in laboratory rats]. / Model experimental de transplant pancreatic cu drenaj portal sau sistemic la sobolanul de laborator.

The aim of this study was to develop an experimental model of pancreas transplantation in rats as a standardized tool for research in transplant immunobiology. Brown Norway (donors) and Lewis (receptors) rats, males, with an average weight of 220 grams, were used. The diabetes was induced in recipients using streptozocin. The pancreas was harvested with a duodenal stump, a segment of aorta containing the celiac and superior mesenteric artery and the portal vein and transplanted as follows: Group A (n=8) - systemic venous drainage; Group B (n=8) - portal venous drainage. The exocrine drainage of the pancreatic graft was established by para-topic reintegration of the graft duodenal stump in the recipient. Postoperative follow-up consisted of daily measurement of glycemia and macroscopic evaluation of the proximal duodenal stump mounted as a cutaneous stoma. Overall postoperative survival at 8 days was 87,5% for Group A and 75% for Group B. Glycemia levels started to regain normal values in both groups, at 2 days postoperatively. Rejection started at 9 and 10 days postoperatively for Group A and B respectively, being expressed by the gradual re-appraisal of hyperglycemia that followed necrosis of the proximal duodenal stump. The experimental model described is functional and has the advantage of being used either with portal or systemic drainage of the pancreatic graft. The results obtained show no significant difference between the time-points of normal postoperative glycemia when either systemic or portal venous drainage were used.

[Reparation of the parcel defect of duodenum with pediculated jejunal patch by laparoscopy. Experimental study]. / Repararea leziunii parcelare duodenale cu patch jejunal pediculat pe cale laparoscopica. Studiu experimental.

The objectives were to evaluate the intraoperative aspects of the repairing by laparoscopy of a parcel duodenal defect, using a pediculated jejunal patch and to emphasize the intraoperative complications. The research has been made on 6 pigs. The pediculated jejunal patch was been achieved by excluding from the intestinal tract of a 2-4 cm segment with nutritional pedicle and the cut of intestinal tube on the anti-mesenteric border. The suture of the duodenal defect has been accomplished in one layer manner. The animals were followed 2 hours, under anesthesia. There was not intraoperative mortality, wether conversion to laparotomy. There was been a good cover of the defect, without any leakage. We did not notice intraperitoneal blood or bile. The duodenoplasty with pediculated jejunal patch is effective. The laparoscopic accomplishing of this procedure has no complications and it can be applied in clinical activity for selected cases.