A chimeric flap model in dogs

Prelamination is sometimes required for reconstruction of specialized organs. The purpose of this study was to create a chimeric flap model in dogs for prelamination. The anatomy of the deep and superficial caudal epigastric vessels, which supply the rectus abdominis muscle and superficial ventral fascia, respectively, were measured in 14 dogs. Their lengths were ~30 mm with the arteries averaging 1.4 mm and veins, 2.5 mm in diameter. These vessels shared a 10-mm-long common trunk with the artery averaging 2 mm and the vein, 3.2 mm in diameter. Chimeric flaps were successfully raised in six dogs based on the common vascular trunk, and they remained well perfused 3 weeks after prelamination. The perfusion territory of the abdominal skin measured 25 cm long and 10 cm wide with methylene blue injection. This study suggests that the caudal epigastric system can be a suitable chimeric flap model in dogs.     

Evaluation of Role of Arterialization of Venous Flaps in Abdomen in Rats

Introduction  Reconstruction forms the primary tenet in plastic surgery. Venous flaps are a known option but the survival is limited. Arterialization of venous flap can enhance its survival. While various techniques of arterialization of venous flaps are described, there are very few studies comparing them. Material and methods  The current study was conducted among 34 rats weighing 160 to 200 grams. The rats were divided into four groups. Group I—islanded epigastric flap was raised with superficial caudal epigastric vessels as pedicle. Group II—arterialized flow through venous flap was raised with superficial caudal epigastric vein (SCEV) as afferent and lateral thoracic vein as drainage vein. Side-to-side anastomosis was done between femoral artery and vein, lateral to the origin of superficial caudal epigastric artery. Group III—after raising the flap, as in group II, femoral vein was ligated proximal to superficial caudal epigastric vessels. Group IV—an arterialized flow through venous flap was raised with superficial caudal epigastric vein as afferent and lateral thoracic vein as drainage vein. End-to-side anastomosis was done between femoral artery and superficial caudal epigastric vein. Animals that died before completion of the study were excluded. The color changes of flaps were noted. Flap survival was expressed as a percentage of the total flap surface area. The patency of anastomosis was seen on postoperative day 5. Results  There was no total flap failure. On statical analysis, the flap survival area on day 5 between Group I and Group IV was not significant ( p value 0.431). The survival area in Group I (78.85 ± 10.54%) was comparable to Group IV (65.71 ± 20.70%). Group II and III had poor results as compared with Group I. In four rats, thrombosis of arteriovenous anastomosis was noted with flap survival area of 30 to 33%. Conclusion  It was noted that epigastric venous flaps with end-to-side anastomosis between femoral artery and superficial caudal epigastric vein (group IV) have survival area comparable to islanded flaps.     

Detection of free radicals in reperfused dog skin flaps using electron paramagnetic resonance spectroscopy: a pilot study.

This is a preliminary investigation of the usefulness of spin-trapping electron paramagnetic resonance (EPR) in detecting oxygen-derived free radicals after reperfusion of ischemic skin flaps. Fourteen island skin flaps approximately 12 cm long by 6 cm wide based on the caudal superficial epigastric vessels were isolated in seven dogs. Seven of the paired skin flaps were subjected to 4 hours of arterial and venous occlusion. The opposite skin flap on each dog served as a perfused control. Spin trapping-EPR was able to detect radical adducts in five of the seven reperfused skin flaps. Hyperfine splitting constants of the radical adducts from the blood of three of the flaps confirmed biologically derived free radical production. Contaminating EPR signals from free radicals created in the manufacture of plastics probably masked any biologically derived radical adducts in the remaining flaps. The authors conclude that EPR-spin trapping may be a valuable tool in the study of the importance of oxygen-derived free radicals in the failure of skin flaps subjected to transient ischemia.     

Colour Doppler ultrasound evaluation of haemodynamic changes in free tram flaps and their donor sites.

Colour Doppler ultrasound (US) was used to measure the blood flow in the donor and recipient arteries as well as in the deep superior epigastric artery of 10 patients having free transverse rectus abdominis myocutaneous (TRAM) flaps. The peak, minimum and mean velocities, the diameter of the vessel, and the resistance index of both the deep superior and inferior epigastric arteries and thoracodorsal arteries were recorded preoperatively and at 4-6 and 15-30 days postoperatively. Colour Doppler US showed increased minimum velocity and decreased resistance index in the pedicle (p < 0.05) throughout the follow-up when compared with the baseline. In the ipsilateral superior epigastric artery the mean and minimum velocities increased (p < 0.05) while the resistance index decreased (p < 0.05) during the first month postoperatively. No changes were recorded in the opposite epigastric arteries or in the control vessel (opposite thoracodorsal artery). In all patients the diameter of the deep inferior epigastric artery was larger than that of the superior epigastric and remained so after the transfer. From the fourth to the thirtieth postoperative day blood flow increased in the free TRAM flap, presumably because of decreased vascular resistance. Blood flow also increased in the superior epigastic artery on the donor side after free TRAM transfer as expected (indicating the delay phenomenon), but harvesting the flap did not affect the circulation in the opposite rectus abdominis muscle. The inferior epigastric arterial system was dominant in all patients.     

Colour Doppler Ultrasound Evaluation of Haemodynamic Changes in Free Tram Flaps and Their Donor Sites

Colour Doppler ultrasound (US) was used to measure the blood flow in the donor and recipient arteries as well as in the deep superior epigastric artery of 10 patients having free transverse rectus abdominis myocutaneous (TRAM) flaps. The peak, minimum and mean velocities, the diameter of the vessel, and the resistance index of both the deep superior and inferior epigastric arteries and thoracodorsal arteries were recorded preoperatively and at 4-6 and 15-30 days postoperatively. Colour Doppler US showed increased minimum velocity and decreased resistance index in the pedicle ( p < 0.05) throughout the follow-up when compared with the baseline. In the ipsilateral superior epigastric artery the mean and minimum velocities increased ( p < 0.05) while the resistance index decreased ( p < 0.05) during the first month postoperatively. No changes were recorded in the opposite epigastric arteries or in the control vessel (opposite thoracodorsal artery). In all patients the diameter of the deep inferior epigastric artery was larger than that of the superior epigastric and remained so after the transfer. From the fourth to the thirtieth postoperative day blood flow increased in the free TRAM flap, presumably because of decreased vascular resistance. Blood flow also increased in the superior epigastic artery on the donor side after free TRAM transfer as expected (indicating the delay phenomenon), but harvesting the flap did not affect the circulation in the opposite rectus abdominis muscle. The inferior epigastric arterial system was dominant in all patients.     

游离胸背动脉穿支皮瓣桥式移植修复小腿软组织缺损

目的总结游离胸背动脉穿支皮瓣或肌瓣桥式移植修复小腿软组织缺损的临床应用效果。方法自2006年9月至2009年1月,应用游离胸背动脉穿支皮瓣或肌瓣桥式移植修复小腿软组织缺损11例,缺损范围4cm×8cm至8cm×22cm。皮瓣切取连带肩胛下与旋肩胛血管,血管蒂呈T形,与健侧小腿胫后动脉行端端吻合,血管蒂用中厚网状游离植皮覆盖。结果除1例术后皮瓣远端发生小的表浅感染,经换药后愈合外,本组皮瓣全部成活。术后随访9个月至3.6年(平均2.9年),没有发现明显的供区功能障碍,供区与受区外形较好,健侧小腿经临床观察与Doppler检查,胫后动脉通畅。结论本方法适用于修复四肢软组织缺损后,患者仅存1条主要动脉者;行桥式游离胸背动脉穿支皮瓣或肌瓣移植不损伤健侧小腿胫后动脉,降低了对供区的损伤。     

皮瓣法阴道再造术41例分析

目的总结先天性无阴道或阴道肿瘤切除术后阴道重建的方法及疗效。方法对先天性无阴道的29例、两性畸形的4例、阴道肿瘤的8例患者采用皮瓣法行阴道重建,包括下腹壁皮瓣22例、腹壁下动脉穿支皮瓣5例、腹直肌肌皮瓣8例、阴囊皮瓣1例、阴股沟皮瓣5例。结果术后下腹皮瓣部分坏死1例,其余皮瓣全部成活。随访3~23个月,1例下腹壁皮瓣者发生阴道口狭窄,1例阴股沟皮瓣者阴道变浅,余再造阴道满意。结论各种皮瓣方法再造阴道有其优缺点,需要根据患者的情况加以选择。     

下腹部横行腹直肌肌皮瓣联合腹壁下动脉穿支皮瓣乳房再造术

目的 探讨应用下腹部腹直肌肌皮瓣联合腹壁下动脉穿支皮瓣行乳房再造的手术方法，并分析其适应证。方法 以健侧腹直肌为肌蒂、患侧腹壁下动、静脉穿支为吻合血管蒂形成下腹部横行腹直肌肌皮瓣与腹壁下动脉穿支联合皮瓣，将腹壁下动、静脉与患侧胸背血管或胸廓内血管相吻合，进行乳房再造。结果 自2003年以来，于临床应用17例，所有皮瓣皆成活，随访3～12个月，再造乳房外形满意。结论 下腹部腹直肌肌皮瓣联合腹壁下动脉穿支皮瓣，具有血运可靠、提供组织量丰富、塑形自由度大、供区损伤较小等优点，尤适宜需要移植体积多以及胸廓内血管受损的乳房再造患者。     

Versatility of rectus abdominis free flap for reconstruction of soft-tissue defects in extremities

Rectus abdominis flaps, whose blood supply is mainly provided by superior and deep inferior epigastric vessels, are suitable not only for local transfer but also as free flaps. Based on abundant anastomoses of deep inferior epigastric vessels with other vessels such as superior epigastric vessels, lower intercostal vessels, subcostal vessels, lumbar vessels, superficial epigastric vessels, and superficial and deep iliac circumflex vessels, the rectus abdominis flap may be designed as a vertical flap, transverse flap, or oblique flap. From September 1995-October 2002, 42 free rectus abdominis flaps were transferred to reconstruct a variety of soft-tissue defects. The size of rectus abdominis flaps ranged from 6-25 cm in length and 5-12 cm in width. The overall success rate was 100% (42 of 42). The donor area was closed directly in 8-10-cm-wide flaps, leaving an inconspicuous scar. Larger flaps required skin grafting. After a mean 7-month (range, 3 weeks-18 months) follow-up, all flaps have healed uneventfully, and donor abdominal morbidity is minimal.     

Transmidline abdominal skin flap model in pig: refinements and advancements

Abdominal flaps have recently gained considerable popularity in breast reconstruction, and their importance and advantages have been widely accepted. Given the unreliability of the distal parts in these flaps and the advancement of microsurgery, many modifications and improvements have been made. To get a better understanding of these flaps, researchers have encouraged the search for a suitable flap model. The purpose of this study was to clarify the anatomical and physiological features of the transmidline abdominal flap model in pig. We included 16 white female Yorkshire pigs in this study. In six pigs, the vascular anatomy of the abdominal region was studied by multidetector row computed tomographic angiography and anatomic dissection. In the remaining 10 pigs, three kinds of transmidline abdominal flap models were established. The pigs were scanned on the abdominal flap to evaluate the perfusion zones after the true abdominal transmidline flap was created, and then they were sacrificed to determine the flap survival area 7 days after surgery. The results of the study were as follows. (1) The pig's deep inferior epigastric vessels were smaller than deep superior epigastric vessels both in length and diameters. (2) The deep superior epigastric artery always bifurcates into two groups; each group gives off five or six branches. (3) The superficial superior epigastric veins were present, while the superficial epigastric arteries were absent in all the animals included. (4) The linea alba abdominis was tough and lack of vascular structures. The average perfusion units were 197.0?±?24.2, 103.2?±?36.4, 138.8?±?25.4, and 30.2?±?11.8 from zone I to zone IV. All the flaps underwent partial necrosis. The flap survival area percentage was 85.9?±?4.1%. The transmidline abdominal skin flap in pig is a reliable and true abdominal flap model for future physiological studies, especially the circulatory dynamics in transmidline abdominal flaps.     

The extended abdominal wall flap for transplantation

Introduction and aims

Patients with extensive loss of the abdominal wall tissue have few options for restoring the abdominal cavity. Composite tissue allotransplantation has been used for limited abdominal wall reconstruction in the setting of visceral transplantation, yet replacement of the entire abdominal wall has not been described. The purpose of this study was to determine the maximal abdominal skin surface available through an external iliac/femoral cuff-based pedicle.

Materials and methods

Five human cadaveric abdominal walls were injected with methylene blue to analyze skin perfusion based on either the deep inferior epigastric artery (DIEA; n = 5) or a cuff of external iliac/femoral artery (n = 5) containing the deep circumflex iliac, deep inferior epigastric, and superficial inferior epigastric, and superficial circumflex iliac arteries.

Results

Abdominal wall flaps were taken full thickness from the costal margin to the midaxillary line and down to the pubic tubercle and proximal thigh. In all specimens, the deep inferior epigastric, deep circumflex iliac, superficial inferior epigastric, and superficial circumflex iliac arteries were found to originate within a 4-cm cuff of the external iliac/femoral artery. Abdominal wall flaps injected through a unilateral external iliac/femoral segment had a significantly greater degree of total flap perfusion than those injected through the DIEA alone (76.5% ± 4% vs 57.2% ± 5%; Student t test, P < .05).

Conclusions

Perfusion of a large portion of the abdominal wall is possible using a single-vessel anastomosis through a short segment of the external iliac/femoral system. Perfusion is significantly greater than that based on the DIEA vessel alone.     

Intraoperative evaluation of blood flow in the internal mammary or thoracodorsal artery as a recipient vessel for a free TRAM flap

Although the free microvascular transverse rectus abdominis musculocutaneous (TRAM) flap is in routine use for breast reconstruction, little is known of its hemodynamics. The purpose of this study was to determine whether any differences exist when the free TRAM flap is anastomosed to the thoracodorsal or internal mammary vessels. The study comprised 25 patients receiving a free TRAM flap for breast reconstruction. The thoracodorsal vessels were used as recipients in 21 patients and the internal mammary vessels were used in 4 patients. Blood flow rate was measured directly in the donor and recipient arteries, and after anastomosis by a transit-time ultrasonic flowmeter (CardioMed). Two- and 3-mm probes were used. The blood flow rate in the donor artery (deep inferior epigastric) before flap dissection was 11 +/- 6 ml per minute (mean +/- standard deviation). The rate was significantly (p < 0.05) lower (5 +/- 3 ml per minute) in the recipient thoracodorsal artery than in the donor, but after transplantation it increased to 14 +/- 5 ml per minute (p < 0.05), attaining the same value as the donor artery. The blood flow rate in the intact internal mammary artery was significantly higher (25 +/- 10 ml per minute) than in the donor and thoracodorsal arteries, but after anastomosis it dropped to the same value (12 +/- 3 ml per minute; p < 0.05) as the donor artery. The intake of blood in TRAM flaps supplied by the intemal mammary artery seems to be no greater than that in free flaps anastomosed to thoracodorsal vessels, although the flow in the internal mammary artery was much higher. The authors concluded that the blood supply in a free TRAM flap is independent of the flow in the recipient artery and that thoracodorsal vessels, although often in a scarred bed and radiated, are as suitable for anastomosing a free TRAM flap as are internal mammary vessels.     

Thoracodorsal artery as a free graft for coronary artery bypass grafting.

Arterial myocardial revascularization using different arterial conduits as mammary, radial, gastroepiploic, subscapular and epigastric arteries are well documented. This report describes a preparation and use of thoracodorsal artery as a free graft for coronary artery bypass grafting. The preparation and removal of thoracodorsal artery were performed through right axilla. The artery was used as a free conduit for left anterior descending artery (LAD) in a 58-year-old female for the second revascularization. The saphenous veins, mammary arteries, right radial artery and epigastric artery were not available. The perioperative course was uneventful and we can recommend the graft as an alternative for such cases.     

应用腹壁下动脉穿支皮瓣再造乳房

目的对应用腹壁下动脉穿支(deepinferiorepigastricperforator,DIEP)皮瓣进行乳房再造进结。方法2000年3月~2005年3月,收治18例患者,其中因乳腺癌导致乳房缺损17例,术前行放射治疗者7例放射治疗者10例;先天性Poland’s综合征1例。胸壁缺损范围12cm×8cm~25cm×20cm。应用DIEP皮瓣游离进行乳房再造,皮瓣切取范围12cm×8cm~35cm×22cm。15例乳房再造患者使用的受区血管是胸廓内血管,其中腹壁下动、静脉分别与切断后的胸廓内动、静脉近、远心端行吻合者13例;仅切取一侧腹壁下血管,与胸廓内动、静心端行吻合者2例。3例行即刻乳房再造者使用的受区血管分别是胸背动、静脉和胸背动、静脉加旋肩胛动、静脉。18例患者中16例术后皮瓣全部成活,2例术后出现皮瓣坏死。其中行放射治疗1例,未行放射治疗1例。Poland合征患者术后皮瓣远端约1/3面积坏死。术后半年行乳头再造和乳房修整者2例。2例术后2周出现腹部供瓣区正口部分裂开,行创面清创后,分别应用直接缝合和植皮的方法进行修复。结论DIEP皮瓣在保留了传统下腹部横直肌皮瓣乳房再造所具有的优点同时,可最大限度保留腹直肌的功能,从而避免术后出现腹壁薄弱、腹壁疝等并发目前较理想的乳房再造方式。     

Comparison of normal and venous flaps. An experimental study]

The abdominal skin of 135 rats was fashioned to be normal on venous flap for investigating the difference in quality of the two. For normal flap, the right superficial epigastric artery was used to serve as the nourishing vessel and the left superficial epigastric vein the draining one. For venous flap, the right superficial epigastric vein was made to be the nourishing vessel and the left superficial epigastric vein the draining one. The flap in group I was fed with blood from the distal end of the femoral vein; the flap in group II was supplied with blood from the distal end of the femoral artery; and the flap in group III was nourished with blood from the femoral artery. It demonstrated that the venous flaps in group I were better in quality than the normal flaps in terms of survival rate, elasticity and size of ulcer. However, the results in group II and group III were quite different. As for clinical use, it would be all right to cover small wound with venous flap; while repairing large defect, particularly in exposed part or area near a joint, normal flap should be of the choice.     

Isolated perfusion of a tubed superficial epigastric flap in a rodent model

BACKGROUND: Isolated perfusion models can yield important data regarding metabolism of the skin. An effective model must remain stable during perfusion but respond appropriately to metabolic and vascular stimuli. We describe the design and characterization of a tubed superficial epigastric isolated perfusion flap. MATERIALS AND METHODS: Tubed superficial epigastric flaps were created in 20 male Sprague Dawley rats. Forty-eight hours later the femoral vessels were cannulated and the flaps were perfused using a Krebs-Heinseleit buffer containing albumin for a period of 2 h. In five of the flaps norepinephrine and acetylcholine were added sequentially to the perfusate to determine vascular reactivity. In a further four flaps insulin (20 U/liter) and iodoacetate (5 mM) were added to the perfusate to confirm that the flap was metabolically active and reactive. Venous outflow was collected at regular intervals and analyzed for electrolytes, lactate, and glucose content. Vascularity and skin perfusion were characterized using barium microangiography and methylene blue dye injection. RESULTS: This flap model was found to be stable in terms of arterial pressure, electrolyte levels, and lactate production over the perfusion period. Norepinephrine caused a sharp increase in vascular resistance, which was reversed by administration of acetylcholine. Lactate production increased appropriately with the addition of insulin to the perfusate with a rapid decline following addition of the glycolysis inhibitor iodoacetate. There was no leakage of perfusate or significant swelling of the flap during the perfusion. CONCLUSIONS: The tubed superficial epigastric artery flap makes an effective model for isolated perfusion studies of the skin with a wide range of experimental applications.     

Latissimus dorsi musculocutaneous flap model in the rabbit: a hemodynamic and anatomical study

The rabbit island and peninsular axial pattern latissimus dorsi musculocutaneous (LDM) flaps were assessed for their appropriate use as experimental musculocutaneous flap models. Contralateral island and peninsular LDM flaps (10 X 20 cm) were constructed on rabbits, and their vascular anatomy, hemodynamics, and viability were compared. Anatomical dissections and fluorescein dye studies revealed that the skin overlying the latissimus dorsi muscle received its blood supply mainly from a direct cutaneous branch of the thoracodorsal artery before its entry to the latissimus dorsi muscle. A few small musculocutaneous arteries (perforators) were seen in the proximal portion of the latissimus dorsi muscle, but these perforators provided very little blood supply to the overlying skin. Results from hemodynamic and viability studies with rabbit peninsular and island LDM flaps also indicated that the blood supply from the musculocutaneous arteries to the overlying skin paddle was small and could not reliably support the survival of the cutaneous portion of these musculocutaneous flaps. We conclude that rabbit LDM flaps are different in vascular structure and blood supply compared with the human LDM flaps. Thus, discretion should be advised in applying the rabbit peninsular or island LDM flaps as experimental flap models for the study of the pathophysiology and pharmacology of the musculocutaneous flaps relevant to the clinical situation.     

髂腹股沟带蒂真皮下血管网皮瓣修复手部皮肤脱套伤

目的应用髂腹股沟带蒂真皮下血管网皮瓣修复手部皮肤脱套伤.方法将带旋髂浅血管或腹壁浅血管为蒂的髂腹股沟皮瓣的远端1/3～1/2修剪成带真皮下血管网薄皮瓣,修复除拇指以外的手部大面积皮肤缺损.结果临床应用9例,皮瓣全部成活,外形及运动功能恢复满意.结论带蒂髂腹股沟真皮下血管网皮瓣修复手部皮肤脱套伤是简单、有效的方法.     

Reconstruction of the hand and upper limb with free flaps based on musculocutaneous perforators

Since the advent of perforator flaps, a wide variety of applications have been documented. This study focuses on free flaps based on musculocutaneous perforators, because they have not been well-described in the literature of upper-limb reconstruction. They can be trimmed to be thin and pliable, and may provide large flaps with multiple components on the same pedicle to facilitate three-dimensional inset of flaps. Microvascular free flaps based on musculocutaneous perforators were performed in 36 cases for reconstruction of the thumb and thenar web, palm, dorsum of the hand, wrist, and forearm. They included the anterolateral thigh perforator flap (27 cases), thoracodorsal perforator flap (5 cases), and deep inferior epigastric perforator flap (4 cases). In 2 other cases not included in this series, the thoracodorsal perforator flap could not be elevated due to anatomical variations. There was no failure in this series, but complications included: 1) hematoma in 2 cases, and 2) infection in 2 cases with flap rim necrosis which was treated by a local rotation flap and skin graft. The thin flaps facilitated secondary reconstructive procedures, and only minor effort was required for the debulking procedure of the flaps. On average, these patients required 2.3 occasions of secondary procedures for further reconstruction following coverage with a perforator flap. The perforator flaps provide medium-thickness flaps for coverage of large defects in the upper limb with improved aesthetics and function. With careful dissection of the musculocutaneous perforators and primary thinning of the flaps, the use of a perforator flap is quite safe. Preservation of the muscles leads to better preservation of donor-site functions. Less requirement of secondary debulking procedures is a great advantage. However, caution should be taken in the presence of wound infection.     

腹部双蒂真皮下血管网皮瓣修复手部脱套伤

目的　总结腹部双血管蒂真皮下血管网皮瓣急诊修复手部脱套伤的效果。方法1994年～1997 年对19 例手部脱套伤,急诊采用腹壁下动脉为蒂的薄皮瓣和腹壁浅动脉为蒂的薄皮瓣进行瓦合修复。结果　术后皮瓣全部成活。随访1～3年,手外形美观,皮瓣质地柔韧,伸指正常,拇指对掌功能正常。掌指关节屈曲45°～60°,近指节关节屈曲10°～25°,生活自理。结论　采用腹部双血管蒂真皮下血管网皮瓣修复手部脱套伤具有皮瓣移位后血循环好,抗感染力强,成活率高,修复后手外形美观,不臃肿等特点。