Thermoregulation, Not Just Camouflage: The Unique Vasculature of Giraffe Patches. A Cadaver Study with Clinical Implications

BACKGROUND

Serendipitously, a dead giraffe provided opportunity to study its vascular anatomy. Comparative animal studies have revealed important information for designing new flaps and new microsurgical techniques. So, do giraffe's patches support a thermal window concept, do animals with similar markings and habitat have a similar thermoregulatory role, and could results offer new insight into human thermoregulation and free tissue transfer?

METHODS

Previously described lead-oxide arterial-only injection studies, of a single giraffe, zebra, Africa wild dog, and spotted jaguar, all with wire-encircled pigmented patches; and archival human, pig, dog, cat, and rabbit studies, were compared.

RESULTS

Each giraffe patch was supplied by just a single artery (angiosome) averaging 0.9 mm diameter, that divided near its center and sent dense, long, parallel, radiating spoke-wheel branches averaging 0.62 mm diameter to the patch margin, continuing as reduced-caliber choke anastomoses averaging 0.8 mm to link adjacent patch angiosomes. Uniquely arranged large veins, with an average of 1.66 mm, encircled the patches in the pale skin paralleled by arteriae comitantes averaging 0.22 mm. These arteries, connected to patch angiosomes, filled the veins intermittently by means of arteriovenous (A-V) shunts averaging 0.12 mm in diameter of magnitude never seen before in any species studied. None of the other three animals had angiosome territories matching their pigmented fur, or significant A-V filling.

CONCLUSIONS

This study supports the "thermostatic" concept of the giraffe skin patches, with A-V shunts playing a major role. It affirms the need for further studies of these shunts in human thermoregulation and other flow regulations in physiology, pathology, and free tissue transfer.

In Pursuit of the "Perforator" in the Perforator Skin Flap

Another congress of the World Society for Reconstructive Microsurgery (WSRM) this past year in Bologna was magnificent not just for the presentation of so many keynote lectures by the giants of our field nor the novel and innovative ideas shown by those who will someday follow in those footsteps, but by making all of us realize how many capable microsurgeons there are now practically everywhere in this world, doing incredibly important surgical management of challenges that previously were unmet and resulted in sheer devastation for so many of our patients. How much we are the same in our goals, aspirations, and abilities could not be overlooked, but it is amazing how much we also want to learn more together-each relying on the other. To do so, we must not forget our origins as we appropriately plan for the future. All this we philosophized in our WSRM panel on lower extremity reconstruction, while emphasizing on the surface the perforator flap that at the least today has caught everyone's attention. In this overview to follow, we once again tell two stories, starting with the beginnings of the concept of flaps in showing how the nomenclature has evolved over time according to our various surgical manipulations. Often overlooked, though, is a parallel timeline by the anatomists who have better elucidated the circulation to these flaps, where it will become obvious that often long ago the existence of perforators was recognized by them long before known by the surgeons. At least today, these two paths have at least temporarily intersected. Our pursuit of the "perforator" in the perforator skin flap has come full circle, following the course of the history of the flap itself-a pursuit of excellence.

The quadriceps Femoris allograft as an extension of the Angiosome concept: A cadaveric-based anatomical feasibility study

BACKGROUND

Vascularised composite allo-transplantation (VCA) is emerging as a tailored approach for complex tissue reconstruction. This study focuses on the quadriceps VCA as a potential solution for tissue repair, following trauma, necrotising fasciitis/myositis, or tumor ablation.

METHODS

Dissections were undertaken in 10 adult cadaveric lower limbs to characterize the blood supply to the quadriceps femoris for en bloc muscle allo-transplantation. A mock cadaveric transplantation was performed to (a) define the best neurovascular VCA design and (b) test the feasibility of the procedure. A review of 54 archival radiograph studies from the institution was also performed to further evaluate the muscle vasculature.

RESULTS

In two lower limbs, the quadriceps VCA was harvested designed on the common and superficial femoral vessels and nerve, which revealed a lengthy and bloody dissection, especially of the veins, which could increase clinically with the inability to use a tourniquet for most of the dissection. However, review of our previous archival studies showed that all four quadriceps muscles are supplied within the lateral circumflex femoral angiosome. In a further eight lower limbs, the quadriceps femoris muscle group consistently received its blood supply from the lateral circumflex femoral angiosome, verified by selective lead oxide injections of this artery. The vastus medialis appeared to have a more tenous blood supply distally based on this angiosome. A successful mock cadaveric transplant was performed based on this data.

CONCLUSIONS

We suggest that the best neuromuscular quadriceps VCA should be (a) designed on the lateral circumflex femoral pedicle, (b) should be raised from distal to proximal, and (c) should include the descending genicular vessels as a potential supplemental supply to vastus medialis, should all four muscles be required.

A 10-year Follow-up of a Free Vascularized Fibula Flap Clavicle Reconstruction in an Adult

The free vascularized fibula flap has been widely used for clavicle reconstruction. Limited evidence exists for the long-term outcome of clavicle reconstruction using the free vascularized fibula flap in adults. We report the functional and aesthetic outcome in a 52-year old man a decade after clavicle reconstruction using a free vascularized fibula flap in combination with a modified Richardson Hook Plate. At the 10-year follow-up, panoramic shoulder X-ray showed the modified Richardson Hook Plate had remained firmly in place with the fibula and the hook positioned beneath the acromion. Functionally, the patient presented with a constant shoulder score of 77, with a pain-free symmetrical full range of motion. In conclusion, reconstruction of lateral clavicle defect using free vascularized fibula flap in conjunction with modified Richardson Hook plate may provide patients with excellent long-term functional and aesthetic outcomes.

The gracilis myocutaneous free flap: a quantitative analysis of the fasciocutaneous blood supply and implications for autologous breast reconstruction

Background

Mastectomies are one of the most common surgical procedures in women of the developed world. The gracilis myocutaneous flap is favoured by many reconstructive surgeons due to the donor site profile and speed of dissection. The distal component of the longitudinal skin paddle of the gracilis myocutaneous flap is unreliable. This study quantifies the fasciocutaneous vascular territories of the gracilis flap and offers the potential to reconstruct breasts of all sizes.

Methods

Twenty-seven human cadaver dissections were performed and injected using lead oxide into the gracilis vascular pedicles, followed by radiographic studies to identify the muscular and fasciocutaneous perforator patterns. The vascular territories and choke zones were characterized quantitatively using the ‘Lymphatic Vessel Analysis Protocol’ (LVAP) plug-in for Image J® software.

Results

We found a step-wise decrease in the average vessel density from the upper to middle and lower thirds of both the gracilis muscle and the overlying skin paddle with a significantly higher average vessel density in the skin compared to the muscle. The average vessel width was greater in the muscle. Distal to the main pedicle, there were either one (7/27 cases), two (14/27 cases) or three (6/27 cases) minor pedicles. The gracilis angiosome was T-shaped and the maximum cutaneous vascular territory for the main and first minor pedicle was 35×19 cm and 34×10 cm, respectively.

Conclusion

Our findings support the concept that small volume breast reconstructions can be performed on suitable patients, based on septocutaneous perforators from the minor pedicle without the need to harvest any muscle, further reducing donor site morbidity. For large reconstructions, if a ‘T’ or tri-lobed flap with an extended vertical component is needed, it is important to establish if three territories are present. Flap reliability and size may be optimized following computed tomographic angiography and surgical delay.

Evaluating anatomical research in surgery: a prospective comparison of cadaveric and living anatomical studies of the abdominal wall

BACKGROUND

Cadaveric research has widely influenced our understanding of clinical anatomy. However, while many soft-tissue structures remain quiescent after death, other tissues, such as viscera, undergo structural and functional changes that may influence their use in predicting living anatomy. In particular, our understanding of vascular anatomy has been based upon cadaveric studies, in which vascular tone and flow do not match the living situation.

METHODS

An angiographic analysis of the abdominal wall vasculature was performed using plain film and computed tomography angiography in 60 cadaveric hemi-abdominal walls (from 31 cadavers) and 140 living hemi-abdominal walls (in 70 patients). The deep inferior epigastric artery (DIEA) and all of its perforating branches larger than 0.5 mm were analysed for number, calibre and location.

RESULTS

Both large, named vessels and small calibre vessels show marked differences between living anatomy and cadaveric specimens. The DIEA was of larger diameter (4.2 mm versus 3.1 mm, P < 0.01) and had more detectable branches in the cadaveric specimens. Perforators were of greater calibre (diameter 1.5 mm versus 0.8 mm, P < 0.01) and were more plentiful (16 versus 6, P < 0.01) in cadaveric specimens. However, the location of individual vessels was similar.

CONCLUSIONS

Cadaveric anatomy displays marked differences to in vivo anatomy, with the absence of living vascular dynamics affecting vessel diameters in cadaveric specimens. Blood vessels are of greater measurable calibre in cadaveric specimens than in the living. Consequently, cadaveric anatomy should be interpreted with consideration of post-mortem changes, while living anatomical studies, particularly with the use of imaging technologies, should be embraced in anatomical research.

Advances in the pre-operative planning of deep inferior epigastric artery perforator flaps: magnetic resonance angiography

Imaging of the abdominal wall vasculature prior to deep inferior epigastric artery (DIEA) perforator (DIEP) flaps has been shown to significantly improve surgical outcomes. Although computed tomography angiography (CTA) has been shown to be highly accurate, it is associated with radiation exposure, and as such modalities without radiation exposure have been sought. Magnetic resonance angiography (MRA) has been proposed as such an option. We conducted a pilot study comparing MRA with CTA and with operative findings in six consecutive patients undergoing DIEP flaps for breast reconstruction. The DIEA, superficial inferior epigastric artery (SIEA) and perforators were all assessed with each modality. We found that the DIEA and SIEA were accurately imaged with both CTA and MRA, but that while MRA could identify some major perforators, CTA was more accurate than MRA for perforator mapping. As such, while MRA does have a role in the imaging of DIEA perforators, CTA is still the preferred modality. On the basis of these findings, a larger study into the role for MRA in this setting is warranted.

Rotation mastopexy: an anatomical approach

The goal of a mastopexy is to restore the shape and volume of the breast after ptosis of the breast. Ptosis occurs commonly in response to aging and breastfeeding. A low nipple position on the breast mound can be corrected by addressing the skin envelope, but maintenance of upper pole fullness and a youthful shape of the breast is the challenge to surgeons. To address this, techniques using local glandular flaps and implants have been suggested. A new technique has been created with regard to a detailed knowledge of the breast gland's vascular anatomy. The lower breast gland is raised as a large vascularized flap and rotated into a pocket beneath the upper pole. The operative procedure is presented together with the experience of the first author with a consecutive series of 25 patients.

The pudendal thigh flap for vaginal reconstruction: optimising flap survival

BACKGROUND

The pudendal thigh fasciocutaneous (PTF) flap is a useful flap in perineal reconstruction, that is reliable when small but is traditionally unreliable when large flaps are raised. Large flaps in particular, are associated with an increased incidence of apical necrosis. Thorough descriptions of the vascular anatomy of this flap have been lacking from the literature, with the current study evaluating this anatomy, aiming to provide the anatomical basis for vascular problems and for techniques to maximise its survival.

METHODS

Five unembalmed human cadaveric pelvis specimens were studied. Lead oxide injectant enabled radiographic and dissection analysis of the arterial anatomy of the integument of the perineum.

RESULTS

A consistent pattern of vascular supply was found in all specimens. 1: the blood supply to the pelvic floor was supplied sequentially by the posterior labial/scrotal arteries, cutaneous branches from the anterior branch of the obturator artery, and branches from the external pudendal arteries. 2: these vessels ran close to the midline, medial to the PTF flap. 3: the posterior labial/scrotal arteries were deep to the Colles' fascia and the branches from the obturator artery and external pudendal arteries were located superficial to the Colles' fascia.

CONCLUSION

This study has demonstrated that the PTF flap is a three vascular territory flap and that the pedicle is situated close to the midline. This may explain why regions of the PTF flap may have a potentially precarious blood supply, and suggests that the PTF flap should be designed more medially. Given the third territory of supply to the apex of the flap, a delay procedure may help to avoid flap necrosis.

Does the preoperative imaging of perforators with CT angiography improve operative outcomes in breast reconstruction?

BACKGROUND

Breast reconstruction is increasingly performed with the use of the abdominal wall donor site, with potential complications including donor site morbidity and impaired flap viability. As a tool for selecting the optimal perforators which will ultimately supply the flap, preoperative imaging with computed tomography angiography (CTA) has become increasingly popular. Potential benefits include reduced intramuscular dissection, with faster and safer dissection, reduced donor site morbidity and improved flap vascularity and survival. Despite the potential for improvements in operative outcome, any benefits are yet to be established.

METHODS

A cohort study of 104 breast reconstructions in 88 patients was conducted. All patients underwent breast reconstruction based on an abdominal wall free flap. Of these, 40 patients undergoing preoperative imaging with CTA and 48 patients not undergoing CTA were included, with all CTAs undertaken at a single institution. Length of operation, length of stay, and operative complications were assessed. An evaluation of operative stress was achieved with the use of visual analogue scales (VAS) administered to the surgeons.

RESULTS

The use of CTA was associated with decreased operating time (mean: 77 min for bilateral cases), significantly decreased complications related to flap viability (particularly partial flap loss), and a statistically significant reduction in donor site morbidity. Psychometric testing of surgeons revealed a statistically significant decrease in operative stress (41% decrease) with the use of preoperative CTA.

CONCLUSION

The use of CTA for preoperative imaging in breast reconstruction is associated with improved operative outcomes.

Image-guided, stereotactic perforator flap surgery: a prospective comparison of current techniques and review of the literature

BACKGROUND

Image-guided stereotaxy is a recent advancement in imaging technology, allowing computer guidance to aid surgical planning and accuracy. Despite the use of multiple techniques for patient registration in several surgical specialities, only fiducial marker registration has been described for use in soft tissue reconstructive surgery. The current study comprises an evaluation of the current techniques available for this purpose.

METHODS

A cohort of nine consecutive patients planned for elective free flaps were recruited, with the first five patients (four for the abdominal wall and one anterolateral thigh donor site) undergoing fiducial marker registration with a variable number of fiducial markers in order to determine the optimal number of fiducial markers to be used. Four subsequent patients undergoing perforator flap surgery underwent registration using three available registration modalities: fiducial marker registration, surface matching pointer/landmark and surface matching laser registration.

RESULTS

For the abdominal wall, registration was not able to be achieved with five fiducial markers, and was successfully achieved in all cases with either six or seven fiducial markers. For the anterolateral thigh, registration was achieved with either nine or ten markers. The four patients who also underwent surface-landmark registration and 'Z-touch' laser surface matching registration all failed the registration process.

CONCLUSION

Stereotactic navigation is a useful adjunct to the preoperative imaging of perforator flaps. Fiducial marker registration was able to be achieved in all cases, can be successfully achieved with a low and predictable number of fiducial markers, is highly accurate, and was the only reliable registration process in our experience.

Establishing the case for CT angiography in the preoperative imaging of abdominal wall perforators

Preoperative imaging of the donor site vasculature for deep inferior epigastric artery (DIEA) perforator flaps and other abdominal wall reconstructive flaps has become more commonplace. Abdominal wall computed tomography angiography (CTA) has been described as the most accurate and reproducible modality available for demonstrating the location, size, and course of individual perforators. We drew on our experience of 75 consecutive patients planned for DIEA-based flap surgery undertaking CTA at a single institution. Seven of these cases have been reported to highlight the utility of CTA for preoperative planning, emphasizing the unique information supplied by CTA that may influence operative outcome. Among all cases that underwent preoperative imaging with CTA, there was 100% flap survival, with no partial or complete flap necrosis. We found that in three of the cases described, the choice of operation was necessarily selected based on CTA findings (DIEA perforator flap, transverse rectus abdominis myocutaneous flap, and superficial superior epigastric artery flap). In addition, three cases demonstrate that CTA findings may dictate the decision to operate at all, and one case demonstrates the utility of CTA for evaluating the entire abdominal contents for comorbid conditions. Our experience with CTA for abdominal wall perforator mapping has been highly beneficial. CTA may guide operative technique and improve perforator selection in uncomplicated cases, and in difficult cases it can guide the most appropriate operation or indeed if an operation is appropriate at all. This is particularly the case in the setting of comorbidities or previous abdominal surgery.

Abdominal wall CT angiography: a detailed account of a newly established preoperative imaging technique

Institutional review board approval was obtained for this study, and all patients gave written informed consent. Autologous surgical breast reconstruction with use of abdominal wall donor flaps based on the deep inferior epigastric artery (DIEA) and one or more of its anterior musculocutaneous perforating branches (DIEA perforator flap) is being used with increasing frequency instead of breast reconstruction with use of traditional transverse rectus abdominus musculocutaneous and modified muscle-sparing flaps. Preoperative mapping of the DIEA perforators with abdominal wall computed tomographic (CT) angiography may improve patient care by providing the surgeon with additional information that will lead to optimization of the surgical technique, shorter procedure time, and reduction in the frequency of surgical complications. The branching patterns of the DIEA, the segmental anatomy of the anterior adipocutaneous perforating branches of the DIEA, and the importance of these features in pre- and intraoperative surgical planning necessitate a different approach to abdominal wall CT angiography than that used with other abdominal CT angiographic techniques. In abdominal wall CT angiography, the common femoral artery is used as the bolus trigger, CT scanning is performed in the caudocranial direction, the automatic exposure control feature is disabled, a scaled grid overlay tool is used to present information to the surgeons, and radiation dose is minimized (average dose, 6 mSv). The anatomic accuracy of abdominal wall CT angiography has been investigated in cadaveric and surgical studies, with sensitivity of 96%-100% and specificity of 95%-100%. This detailed description will allow other radiologists and surgeons interested in free DIEP flap surgery to incorporate this useful tool into their practice.

Defining the role for autologous breast reconstruction after mastectomy: social and oncologic implications

Breast reconstruction plays a significant role in the management of breast cancer. The removal of a breast has implications for the psychologic, social, and sexual well-being of the patient, establishing the need for discussion of postmastectomy breast reconstruction with suitable patients. However, operative morbidity and the potential for diminished oncologic safety are ongoing issues of contention. A Medline literature review was performed to evaluate the interplay between the psychosocial need for breast reconstruction in patients after mastectomy and the issues surrounding its oncologic safety. Immediate breast reconstruction does not impair the oncologic safety of breast cancer management, with no increase in local recurrence rates, and no delays in the initiation of adjuvant chemotherapy or radiation therapy (RT). Immediate breast reconstruction in the setting of chemotherapy is not associated with greater complication rates; however, there is some evidence for increased complications in the setting of adjuvant RT. Breast reconstruction has a positive effect on the psychosocial outcomes of mastectomy and is oncologically safe in the immediate and delayed settings. Ultimately, the decision-making process of whether to reconstruct, how to reconstruct, and when to reconstruct requires a multidisciplinary approach, with the patient, plastic surgeon, oncologic surgeon, medical oncologist, and radiation oncologist all contributing.

The angiosome territories of the spinal cord: exploring the issue of preoperative spinal angiography. Laboratory investigation

OBJECT

The angiosome concept has been the subject of extensive research by the senior author (G.I.T.), but its specific applicability to the spinal cord was hitherto unknown. The aim of this study was to see if the spinal cord vasculature followed the angiosome concept and to review the usefulness of preoperative spinal angiography in surgery for spinal disorders. Spinal cord infarction and permanent paraplegia may result from inadvertent interruption of the artery of Adamkiewicz. Spinal angiography, which may enable avoidance of this catastrophic complication, is still not commonly used.

METHODS

Two fresh cadavers were injected with a gelatin-lead oxide mixture for detailed comparative study of spinal cord vasculature. One cadaver had insignificant vascular disease, whereas the other had extensive aortic atherosclerosis, presenting a unique opportunity for study. After removal from each cadaver, radiographs of the spinal cords were obtained, then photographed, and the vascular territories of the cords were defined.

RESULTS

Four angiosome territories were defined: vertebral, subclavian, posterior intercostal, and lumbar. These vascular territories were joined longitudinally by true anastomotic channels along the anterior and posterior spinal cord. Anastomosis between the anterior and posterior vasculature was poor in the thoracolumbar region. The anterior cord relied on fewer feeder arteries than the posterior, and the anterior thoracolumbar cord depended on the artery of Adamkiewicz for its supply. In chronic aortic disease with intercostal artery occlusion at multiple levels, a rich collateral circulation supporting the spinal cord was found.

CONCLUSIONS

The arterial supply of the spinal cord follows the angiosome concept. The atherosclerotic specimen supports the suggestion that the blood supply is able to adapt to gradual vascular occlusion through development of a collateral circulation. Nevertheless, the spinal cord is susceptible to ischemia when faced with acute vascular occlusion. This includes inadvertent interruption of the artery of Adamkiewicz. The authors recommend the use of preoperative spinal angiography to prevent possible paraplegia in removal of thoracolumbar spinal tumors.

Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and doppler ultrasound

BACKGROUND

Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA.

METHODS

Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team.

RESULTS

Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography.

CONCLUSION

Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

The lymphatic anatomy of the breast and its implications for sentinel lymph node biopsy: a human cadaver study

Background

Current understanding of the lymphatic system of the breast is derived mainly from the work of the anatomist Sappey in the 1850s, with many observations made during the development and introduction of breast lymphatic mapping and sentinel node biopsy contributing to our knowledge.

Methods

Twenty four breasts in 14 fresh human cadavers (5 male, 9 female) were studied. Lymph vessels were identified with hydrogen peroxide and injected with a lead oxide mixture and radiographed. The specimens were cross sectioned and radiographed to provide three dimensional images. Lymph (collecting) vessels were traced from the periphery to the first-tier lymph node.

Results

Lymph collecting vessels were found evenly spaced at the periphery of the anterior upper torso draining radially into the axillary lymph nodes. As they reached the breast some passed over and some through the breast parenchyma, as revealed in the cross-section studies. The pathways showed no significant difference between male and female specimens. We found also perforating lymph vessels that coursed beside the branches of the internal mammary vessels, draining into the ipsilateral internal mammary lymphatics. In some studies one sentinel node in the axilla drained almost the entire breast. In most more than one sentinel node was represented.

Conclusion

These anatomical findings are discordant with our current knowledge based on previous studies and demand closer examination by clinicians. These anatomical studies may help explain the percentage of false-negative sentinel node biopsy studies and suggest the peritumoral injection site for accurate sentinel lymph node detection.

The lymphatics of the skin filled by a dermal backflow: an observation in a scarred cadaver leg

There have been few photographic studies done on lymphatics of human skin with previous images obtained by indirect dye injection into the dermis. We have developed a direct injection technique for investigating the lymphatic system in human adult cadavers and used this to investigate superficial lymphatics of the legs in a fresh human cadaver. We found an unusual observation in a skin graft scarred leg when the radio-opaque mixture injected into a lymph collecting vessel in the dorsal foot filled the skin lymphatics in the mid-lateral pretibial region. Further radiological investigation revealed that the dermal back flow was associated with a blockage of the lymph collecting vessel within the skin graft scar. We also found tracer transport through a circuitous pathway from the blocked collecting vessel to an adjacent intact collecting vessel. The transilluminated image of the skin demonstrated a three dimensional polygon of lymph capillaries and precollecting lymphatics in the dermis.

Changes in the Lymph Structure of the Upper Limb after Axillary Dissection: Radiographic and Anatomical Study in a Human Cadaver

BACKGROUND

There have been very few anatomical reports on the changing lymph structure of the upper limb after axillary dissection despite its clinical significance for predicting skin cancer recurrence in the limb and secondary lymphedema. The authors used both upper limbs harvested from a fresh human cadaver that had undergone unilateral right radical mastectomy and radical axillary dissection for breast cancer.

METHODS

Hydrogen peroxide was used to identify and inflate the lymphatic vessels. Individual channels were injected with a radiopaque lead oxide mixture and recorded on x-ray film.

RESULTS

Results from the normal left upper limb were similar to results from the authors' previous studies. However, the right limb from the mastectomy side showed remarkable differences and revealed that the lymph node clearance in the axilla had been incomplete on that side. The major difference was the almost complete absence of the superficial lymphatic network in the right arm, proximal to the elbow, because of fibrosis and blockage of the lymphatic channels. A circuitous pathway was identified that bypassed the blocked lymphatics in the arm to reach the deep system. This was facilitated often by backflow through precollectors and avalvular lymph capillaries in the dermis of the forearm, to reach eventually the few remaining lymph nodes in the axilla.

CONCLUSIONS

Previously undetected lymph channels connecting the superficial and the deep lymphatic system had opened up because of the blockage of superficial lymphatic vessels caused by axillary dissection. It is presumed that these channels prevented lymphedema in this case.

Refinements of the Radiographic Cadaver Injection Technique for Investigating Minute Lymphatic Vessels

BACKGROUND

The authors previously reported a new technique with which to delineate the lymphatic vessels, using hydrogen peroxide to identify them and a lead oxide suspension to demonstrate them on radiographs. This technique provided excellent studies of the lymph vessels in human cadavers, but there was still room for improvement.

METHODS

Lymph collecting vessels run superficially in some regions, where they may be damaged while the surgeon is attempting to find them. Vessels smaller than 0.3 mm in diameter could not be cannulated with a 30-gauge needle, which was the smallest the authors had available, and the lead oxide suspension often blocked this cannula. The authors also encountered problems holding the cannula steady.

RESULTS

The authors solved these problems by using a mixture of hydrogen peroxide and ink to better identify the lymphatics, an extruded glass tube instead of a metal needle to cannulate them, an agate pestle and mortar to grind the lead oxide into finer particles, powdered milk to suspend the lead oxide, and a micromanipulator to facilitate accurate and steady cannulation of the vessels.

CONCLUSION

This study developed these modifications to focus on tributaries of the collecting lymphatic channels that are smaller than 0.3 mm in diameter.

The lymphatic territories of the upper limb: anatomical study and clinical implications

BACKGROUND

Current understanding of the pattern of lymph channels is largely dependent on the anatomical studies of Sappey performed in the nineteenth century, when mercury was injected into human cadavers and the lymphatics were dissected. These studies have not been repeated because the use of mercury is now prohibited as a result of its toxicity. The aim of this study was to reappraise the gross lymphatic anatomy and lymph node connections using a radiologic technique. A period of 3 years was required for development of a new method.

METHODS

The definitive technique used hydrogen peroxide to identify lymphatic vessels and to inflate them. The individual channels were injected with a radiopaque lead oxide mixture and recorded on x-ray film. Each channel was dissected meticulously under the surgical microscope and its course examined in relation to the regional lymph nodes. This method was then applied to 14 human cadaver upper limbs obtained from 10 different cadavers.

RESULTS

The authors found that the superficial lymphatic vessels course within the subcutaneous fat in close proximity to the main subcutaneous veins. Communication between the superficial and the deep lymphatic systems was not identified in these studies.

CONCLUSIONS

Most lymph vessels were seen to flow into one main (sentry) lymph node in the axillary region; however, some of the lymph vessels ran along the posterior forearm, bypassing the "sentry" node to reach other smaller nodes.

Angiosome territories of the nerves of the upper limbs

BACKGROUND

The use of free vascularized nerve grafts requires intimate knowledge of the blood supply of peripheral nerves. The authors aimed to demonstrate radiographically the topography of the upper limb nerves with their blood supply, and to examine them as an application of the angiosome concept. An angiosome is a three-dimensional block of composite tissue supplied by a single source artery.

METHODS

This anatomical study involved the meticulous dissection of four fresh upper limb specimens injected intraarterially with a gelatin-lead oxide mixture. The nerves were tagged circumferentially with copper wire and radiographs were taken of the nerves with their arterial blood supply. The median, ulnar, radial, musculocutaneous, and axillary nerves were examined.

RESULTS

The authors showed that the nerves of the upper limb were supplied segmentally by source vessels, which reinforced the angiosome concept. The suitability of each nerve for harvest in free vascularized nerve transfer was assessed according to its pattern of blood supply.

CONCLUSIONS

The authors' work has a wide range of clinical applications and provides an anatomical basis for neurovascular and neurocutaneous flaps and free vascularized nerve grafting.

A New Radiographic Cadaver Injection Technique for Investigating the Lymphatic System

Studies of the gross anatomy of the lymphatic system are few and far between when compared with those of other vascular systems. Our knowledge of the anatomy of the lymphatic system is so limited that it seems vastly inadequate in explaining the clinical manifestations caused by its disorder. This study has developed an effective method to identify the lymphatics using hydrogen peroxide, to demonstrate the lymphatic vessels radiographically using a lead oxide suspension, and to dissect them out in adult human cadavers.

Angiosomes of the brachial plexus: an anatomical study

This anatomical study analyzed the neurovascular relationships of the brachial plexus. Ten fresh cadaveric brachial plexuses were examined after injection of the arterial system. The vascular anatomical features of the brachial plexus were documented with microdissection after lead oxide/gelatin injection. The specimens were analyzed by using radiography (including digital subtraction techniques) and light-microscopic, macroscopic, and digital photography. Four angiosomes, based on the subclavian, axillary, vertebral, and dorsal scapular arteries, were observed. As noted in previous angiosome studies, connections between angiosome territories lay within tissues, in this case, nerve trunks. Nutrient vessels penetrated nerve trunks at points of branching within the brachial plexus, with a Y-shaped mode of division on entry. The vascular supply was markedly rich, often with true anastomotic connections occurring within the nerves. There was much variation in supply, depending on the vascular anatomical features of the subclavian artery.

Subglandular Breast Reduction: The Evolution of a Minimal Scar Approach to Breast Reduction

The authors describe a new modification of the breast reduction procedure. By means of an inframammary incision, the breast is mobilized from the chest wall, and a "doughnut" annulus of breast tissue is removed from the undersurface of the gland. No skin is excised. The nipple-areola complex is left attached to a central core of breast tissue that receives its blood supply from the subdermal plexus of vessels. When the resulting defect is closed within the breast by strategically placed sutures, the base of the gland is narrowed, the breast is projected forward, and the circumareolar and vertical scars of other techniques are eliminated. The authors report their results in a series of 37 patients.

Angiosome Territories of the Nerves of the Lower Limbs

This anatomical study involved the meticulous dissection of three fresh cadaveric specimens to characterize the vascular supply of the nerves of the lower limb. The findings demonstrated that the nerves were supplied segmentally by source vessels, which were color-coded to match the corresponding angiosomes. The segments were then classified into five categories according to whether the nerves and source vessels were branched or unbranched, which has clinical relevance for harvesting of nerves for vascularized nerve transfers.

Aplasia cutis congenita of the scalp, the skull, and the dura

A newborn baby boy presented with a full thickness defect of the scalp, skull, and dura measuring 6 x 7 cm caused by aplasia cutis congenita. Full thickness loss is extremely rare and to our knowledge this case is the twenty-first reported. It has an established mortality of up to 55%. An encephalocele forced us to do an emergency operation with a single large scalp flap based on the supratrochlear and superficial temporal arteries. After revision the child is now 9 months old and progressing well. There are several ways to treat these rare and delicate cases.

The angiosomes of the body and their supply to perforator flaps

An angiosome is a composite block of tissue that is supplied anatomically by source (segmental or distributing) vessels that span between the skin and bone. In addition to supplying the deep tissues, the source vessels of these angiosomes supply branches to the overlying skin, which pass either between the deep tissues or through the deep tissues, usually muscle, to pierce the outer layer of the deep fascia, usually at fixed skin sites. Hence, perforator flaps, when dissected to the underlying source vessels, involve tracing vessels either between the deep tissues, whether muscle tendon or bone, or through the deep tissues, usually muscle.