荒木 淳

Reconstruction of the external auditory canal (EAC) after malignant tumor resection requires functional, aesthetic, and radiation-resistant coverage. However, flap selection criteria remain lacking. The authors retrospectively reviewed 11 patients who underwent EAC reconstruction using a temporoparietal fascia flap (TPFF), temporalis muscle flap (TMF), or a combination of both between 2004 and 2025. Clinical data, surgical techniques, and outcomes were analyzed. Reconstruction procedures involved TPFFs alone (n=6), TMFs alone (n=2), and a combination of both (n=3). TMFs were used when the superficial temporal artery was sacrificed or when a TPFF alone was insufficient in volume. Skin grafts from the groin were used in all but 1 case. Seven patients received postoperative radiotherapy, with no radiation-related complications. TPFFs and TMFs, used alone or in combination, are safe and effective for EAC reconstruction. As reflected in our proposed algorithm, flap selection should be based on defect volume and vascular availability.

BACKGROUND: Local recurrence after surgical resection is a major clinical challenge in patients with advanced head and neck cancer (HNC). We previously reported using transfer of a flap treated with dendritic cells (DCs) ("immuno-flap") as a novel cancer immunotherapy in a rat model of HNC. However, several problems, such as the improvement of DC yield and the verification of DC tracking, remained to be solved. METHODS: The initial DC production protocol was revisited, and the specific mechanism of the antitumor effect associated with functional DCs was investigated. RESULTS: The yield and the purity of potent DCs were improved, and an in vivo tracking experiment revealed that, when injected into the skin flap, the DCs migrated to local lymph nodes within 24 h. In an in vivo long-term protection model in which DCs were injected into the skin flap weekly for 4 weeks, no strong antitumor effect on HNC tumor progression was observed, but a remarkable pathological effect was verified. Moreover, an enzyme-linked immunospot assay demonstrated that more CD8+ T cells positive for PD-1, CD40LIG, and TNF-α expression and producing interferon γ specific to SCC-158 tumor cells were identified in tumors and spleens from rats treated using immuno-flaps. CONCLUSIONS: These results indicate that immuno-flap transfer to prevent local recurrence in patients with HNC has potential for clinical application given the improved yield and quality of antitumor DCs.

BACKGROUND: Options for microscopic hepatic artery (HA) reconstruction include direct anastomosis (DA), arterial transfer (AT), and graft interposition (GI). Despite the advantage of AT in requiring only one anastomosis site, its clinical applicability and outcomes in HA reconstruction after hepatobiliary tumor resection remain underexplored. This study aimed to evaluate the feasibility and safety of AT compared with DA. METHODS: A retrospective analysis of patients who underwent microscopic HA reconstruction after hepatobiliary tumor resection between 2003 and 2024 was performed. Feasibility was assessed based on the proportion of cases successfully reconstructed without GI and the distribution of cases among the DA, AT, and GI groups. Safety was evaluated by comparing the severity of overall complications, incidence of potential complications related to decreased HA flow, incidence of postoperative anastomotic thrombosis, and survival outcomes between the AT and DA groups. RESULTS: Among 130 patients, 99.2% of cases did not require GI, with the DA, AT, and GI groups accounting for 56%, 43%, and 0.8%, respectively. No significant differences between the AT and DA groups were observed in the severity of overall complications (p = 0.27), incidence of potential complications related to decreased HA flow (p = 0.50), postoperative anastomotic thrombosis (p > 0.99), or five-year overall survival rate (29.7% vs. 35.1%, p = 0.37). CONCLUSIONS: AT provides favorable outcomes comparable to DA, even in complex resections. AT is a safe and feasible option for microscopic HA reconstruction when DA is not feasible, effectively minimizing the need for GI.

BACKGROUND: The external jugular vein (EJV) is commonly used as a recipient vein in free flap head and neck reconstruction. However, the branching patterns of the EJV vary significantly, influencing its usability during surgery. In this study, we aimed to classify the confluence patterns of the EJV by using preoperative contrast-enhanced computed tomography scans to assess its suitability as a recipient vein. METHODS: A retrospective observational study was conducted using 100 side images of 50 patients who underwent contrast-enhanced computed tomography before head and neck reconstruction between April 2022 and November 2022. EJV confluence was categorized into 4 types: subclavian vein (SCV), venous angle (junction of the SCV and internal jugular vein [IJV]), IJV, and absence of the EJV (non-EJV). The frequency of each pattern was then calculated. RESULTS: The EJV drained into the SCV in 47%, the venous angle in 37%, and the IJV in 11% of cases, whereas 5% showed no EJV. In the IJV type, the proximal EJV can be ligated during neck dissection or resection of the IJV, rendering up to 16% of cases unsuitable for EJV-based microvascular anastomosis (combined IJV and non-EJV types). CONCLUSIONS: Preoperative imaging is essential to confirm the confluence pattern of the EJV, particularly in cases where resection of the IJV is planned. For patients without EJV- or IJV-type patterns, alternative recipient veins should be prepared in advance to avoid intraoperative complications. This approach underscores the importance of interdisciplinary planning in head and neck reconstruction.

BACKGROUND: The anterolateral thigh (ALT) flap is a versatile option for reconstructive surgery due to the availability of multiple tissue types and minimal donor-site morbidity. However, donor-site seroma formation remains a poorly understood complication, particularly with regard to its severity. In this study, we aimed to investigate the incidence, severity, and factors associated with seroma formation after ALT flap harvesting. METHODS: We conducted a retrospective analysis of 150 patients who underwent ALT flap harvest between November 2020 and September 2023. Donor-site seromas were graded using the Clavien-Dindo classification, and patients were divided into 2 groups based on the presence or absence of seromas. Logistic regression analysis was performed to identify independent factors associated with seroma formation. RESULTS: Seroma formation occurred in 18.0% of patients. Most cases (70.4%) were classified as Clavien-Dindo grade 1, requiring only conservative management, whereas 29.6% (5.3% of all patients) were classified as grade 3a or higher, necessitating surgical intervention. Male sex (odds ratio, 3.11; 95% confidence interval, 0.97-9.98; P = 0.039) and fascia lata harvest larger than the skin paddle area (odds ratio, 2.93; 95% confidence interval, 1.26-6.82; P = 0.017) were identified as independent factors associated with seroma formation. CONCLUSIONS: Fascia lata harvests larger than the skin paddle were associated with donor-site seroma formation with ALT flap harvests. Preoperative planning and careful fascia lata harvesting techniques are recommended to minimize complications.

BACKGROUND: This prospective observational multicenter study aimed to provide evidence-based data on the risk factors for feeding tube dependence, oral intake level, and speech function after tongue reconstruction. PATIENTS AND METHODS: This study was conducted by the Oral Pharyngeal Esophageal Operation and Reconstruction Analytical group across 21 Japanese institutions. Patients with oral tongue squamous cell carcinoma who underwent microsurgical reconstruction following subtotal/total glossectomy were included. Functional evaluations were performed 1 year postoperatively. The primary endpoint was postoperative feeding tube dependence. The other outcome variables were oral intake level and speech function at the time of evaluation. RESULTS: Overall, 189 patients were enrolled, of whom 121 (64.0%) were followed up for 1 year after surgery and were eligible for the final analysis. The overall rate of feeding tube dependence was 12.4% (n = 15) at the primary endpoint. Univariate analysis revealed that tongue defect type, laryngeal suspension, and postoperative chemotherapy were associated with feeding tube dependence. The oral intake level was affected by age at surgery, laryngeal suspension, and postoperative chemoradiation. Speech function was affected by age at surgery, American Society of Anesthesiologists physical status (class 2), medical comorbidities of hypertension and cardiac dysrhythmia, primary tumor stage (T4), neck dissection, reconstructive procedure, laryngeal suspension, and postoperative radiation. CONCLUSIONS: This study provides useful data for estimating individual risk factors associated with feeding tube dependence, oral intake level, and speech function before tongue reconstruction. These results can help surgeons and patients make informed decisions and optimize the functional outcomes of tongue reconstruction.

We report a rare anatomical variant of a septocutaneous perforator (SCP) arising from the peroneal artery (PA) and running dorsally around the flexor hallucis longus (FHL) muscle, identified during fibular osteocutaneous flap harvesting for maxillary reconstruction. Typically, SCPs from the PA run ventrally to the FHL, whereas musculocutaneous perforators (MCPs) penetrate the muscle. SCPs running dorsally around the FHL, particularly those arising from the PA, have not yet been reported. A 53-year-old male patient underwent total hard palatectomy, followed by maxillary reconstruction with a fibular osteocutaneous flap. Preoperative computed tomography angiography revealed a perforator from the PA, initially thought to be an MCP due to its mediodorsal course. Intraoperatively, the perforator was identified as the SCP running dorsally around the FHL. This perforator was accidentally ligated during flap harvesting, necessitating perforator-to-perforator anastomosis to restore blood flow. The flap was successfully transplanted into the maxilla, highlighting the importance of preoperative imaging in perforator mapping. If the course of the perforator was correctly identified preoperatively as an SCP arising from the PA and running dorsally around the FHL, the flap could have been harvested without additional microvascular anastomoses. Magnetic resonance angiography, which offers superior differentiation between SCPs and MCPs, may prevent this complication when computed tomography angiography does not provide a definitive assessment of the perforators' course.

The anterolateral thigh (ALT) flap is one of the most versatile and frequently used flaps in reconstructive surgery. Although techniques for flap harvesting are well established, donor-site morbidities remain a common concern. We report the case of an 83-year-old man who underwent oral cancer resection and reconstruction using a right ALT flap. We used a minimally invasive strategy to reduce donor-site morbidity, including microvascular re-anastomosis of the vascular pedicle. The free flap was successfully transferred, and the postoperative course was uneventful. Lower extremity function tests revealed no dysfunction after surgery. In reconstructive surgery, successful flap transfer and minimal donor-site morbidity are essential. Minimally invasive strategies should be promoted in surgical practice.

PURPOSE: This multi-institutional observational study aimed to assess the incidence, severity, and impact of radiotherapy-related late toxicities of the cervical skin and soft tissue in head and neck cancer patients. We also explored patient interest in fat grafting as a potential treatment for skin and soft tissue sequelae. METHODS: This study was conducted across 19 institutions in Japan. The study involved head and neck cancer patients who received ≥ 60 Gy of cervical radiotherapy concomitant with a history of neck dissection and were free of cancer recurrence ≥ 3 years after the final treatment. Consenting outpatients completed a self-administered questionnaire to collect data on symptom severity and the attending outpatient physicians reported data on demographics and treatments in a case report form. RESULTS: A total of 222 patients were enrolled. The incidence proportion of late cervical skin and soft tissue toxicities was 96%, with 32% of patients reporting their symptoms as severe, and 69% of patients reporting an impact on quality of life (QOL). An interest in or consideration of fat grafting was reported by 34% of patients, with a greater desire among those with severe symptoms. CONCLUSION: This study elucidated the incidence, severity, and life impact of late toxicities affecting the cervical skin and soft tissue after radiotherapy for head and neck cancer. These late toxicities were highly prevalent and significantly impacted QOL. There is a substantial demand for new treatments, such as fat grafting, to address these complications and enhance the QOL for survivors of head and neck cancer.

2010年4月から2020年3月までに鼠径皮弁または前外側大腿(ALT)皮弁を用いて舌半側切除後の再建術を受けた14名(鼠径皮弁7名、ALT皮弁7名)を対象として、日本語の発語明瞭度を比較した。術後6ヵ月以降に廣瀬の会話機能評価、タカラ法、日本語100音節語音明瞭度検査を行い、従来の解析法による結果を皮弁間で比較した。その結果、各評価法における患者ごとの点数に有意差はなかった。しかし、新しい解析法による日本語100音節語音明瞭度検査における各音節の発語明瞭度を比較した結果、発語明瞭度は鼠径皮弁のほうが有意に高かった。特に六つの歯茎音のうち、舌を使う四つの調音点全てにおいて鼠径皮弁が上回っていた。舌半側切除再建後の患者ではALT皮弁よりも鼠径皮弁の発語明瞭度が高いことが示された。

BACKGROUND: There is no consensus on the postoperative outcomes of tongue reconstruction. Therefore, the authors developed a novel risk model for predicting dysphagia after tongue reconstruction. METHODS: This retrospective study was conducted by the Oral Pharyngeal Esophageal Operation and Reconstruction Analytical, or OPERA, group across 31 cancer centers and university hospitals in Japan. A total of 532 patients [390 (73.3%) men and 142 (26.7%) women; median age at surgery, 60 years (range, 15 to 88 years)] who were diagnosed with oral tongue squamous cell carcinoma and underwent tongue reconstruction following glossectomy between 2009 and 2013 were included. Independent risk factors were identified using univariate regression analysis and converted to a binary format for multivariate analysis. An integer value was assigned to each risk factor to calculate a total score capable of quantifying the risk of feeding tube dependence. RESULTS: Overall, 54 patients (10.2%) required a feeding tube at the time of evaluation. Predictive factors for feeding tube dependence were advanced age, lower American Society of Anesthesiologists physical status, low body mass index, lower serum albumin, comorbid hypertension and diabetes, extended tongue defect, resection beyond the tongue, laryngeal suspension, postoperative radiation therapy, and no functional teeth. In multivariate logistic regression analysis, age greater than or equal to 58.5 years, postoperative radiation therapy, wider tongue defect, and body mass index less than 21.27 kg/m 2 earned 6, 4, 3, and 2 points, respectively, for a maximum total score of 15. CONCLUSION: The authors' risk model provides a mathematical tool for estimating the individual risk of postoperative feeding tube dependence before tongue reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

BACKGROUND: Pharyngocutaneous fistula formation represents a major postoperative complication following total laryngectomy. We aimed to investigate the risk factors for pharyngocutaneous fistula development after total laryngectomy and to identify factors that lead to severe cases of pharyngocutaneous fistula. METHODS: Patients who underwent total laryngectomy between January 2013 and February 2021 were included in the study and were divided into 2 groups: Those with and without pharyngocutaneous fistula. The severity of pharyngocutaneous fistula was graded using the Clavien-Dindo classification. RESULTS: Patients with pharyngocutaneous fistula experienced longer operative time, greater intraoperative blood loss, greater decrease in perioperative hemoglobin level, and longer postoperative hospitalization. Unlike in lower-severity cases, patients with grade IIIb pharyngocutaneous fistula underwent preoperative radiotherapy or chemoradiotherapy; preoperative treatment was thus a risk factor for higher severity of pharyngocutaneous fistula (odds ratio, 35; P = 0.004). CONCLUSION: Salvage laryngectomy was found to be a predictor of severe pharyngocutaneous fistula development. Prolonged operative time, increased intraoperative blood loss, and decreased postoperative hemoglobin level were found to be predictors of postlaryngectomy pharyngocutaneous fistula formation.

OBJECTIVE: The differences in speech function between groin flap reconstruction and anterolateral thigh (ALT) flap reconstruction after hemiglossectomy have not been clarified to date. This study aimed to compare Japanese speech intelligibility after hemiglossectomy reconstruction using groin and ALT flaps of similar thickness. METHODS: Data of patients who underwent hemiglossectomy reconstruction with groin or ALT flaps between April 2010 and March 2020 were collected from the medical chart database. The ALT flap was the first choice for hemiglossectomy reconstruction, and a groin flap was used when the ALT flap was >10 mm. Cases in which speech intelligibility assessments based on Hirose's 10-point scoring system, the TKR speech test, and the Japanese speech intelligibility test for 100 monosyllables were performed after 6 months postoperatively were extracted. The per-patient scores for each assessment were initially compared between the two flap groups. Then, the results of the Japanese speech intelligibility test for 100 monosyllables were reanalyzed on a syllable-by-syllable basis. RESULTS: Among the 44 hemiglossectomy patients who underwent free-flap reconstruction during the study period, 14 (seven each in the groin flap and ALT flap groups) underwent all three conventional speech intelligibility assessments after 6 months postoperatively. The two groups showed no significant difference in postoperative speech intelligibility in any of the three patient assessment methods. However, in intergroup comparisons based on per-syllable accuracy for each of the 100 monosyllables, the groin flap group showed 19 syllables with a significantly higher accuracy, whereas the ALT flap group showed one such syllable. In particular, five out of the six alveolar consonants (/t/ and /d/) were more accurately articulated in the groin flap group. Per-syllable accuracy was significantly higher in the groin flap group (74.6% vs. 66.7%; 95% confidence interval: 4.6-11.1, p < 0.001). CONCLUSION: In patients undergoing hemiglossectomy reconstruction, our new analysis method, which compared intelligibility by syllables, showed that the groin flap yielded higher speech intelligibility than the ALT flap. This difference was evident at all four articulation points involving the tongue, whereas there was no significant difference at the two articulation points without tongue involvement.

31歳女性。左乳癌に対し乳房温存治療を選択し、BD領域の乳房部分切除を行った。欠損部再建は乳房が大きく十分な量の皮弁が必要なため、胸背動脈筋間中隔穿通枝皮弁(TDAP-sc flap)12×6cmを用いた。術前に画像検査でTDAP-spの血管走行を把握し、皮弁を安全に挙上できた。術後6ヵ月時、再建乳房の整容は良好で、皮弁は全生着を得られ瘢痕拘縮などは認めない。術前の血管評価には3次元画像が非常に有用であった。

Background: Pedicled jejunal flap can be utilized with various tips for esophageal reconstruction in patients with a history of gastrectomy or those who have undergone synchronous esophagogastrectomy. However, the rate of anastomosis leakage is high; therefore, we considered the evaluation of blood flow of the remnant esophagus with indocyanine green in setting the anastomosis site. Methods: Fifty patients who underwent radical esophagectomy with pedicled jejunal flap between January 2011 and June 2020 were identified. From June 2019, blood flow in the pedicled jejunum and remnant esophagus were evaluated to set the anastomosis site of the latter. Usually, the second and third jejunal vessels are transected, and if the jejunal flap cannot reach to the anastomosis point, we actively transect the marginal vessels to stretch the jejunal flap. Microvascular anastomosis between the jejunal branches and the internal thoracic vessels is usually made, and the anastomosis site is set at the well-stained part of the esophagus. Results: Overall, 39 patients underwent the procedure before June 2019 (Group A), and 11 patients underwent the procedure since June 2019 (Group B). No significant difference was found in the patients' background, type of preoperative therapy, presence or absence of ligation of marginal vessels and two-stage operation between the groups. Group A had 16 cases of anastomosis leakage; B had only 1 case (p < 0.05). There were no cases of pedicled jejunum graft necrosis. Conclusion: Assessing remnant esophageal perfusion by indocyanine green imaging in pedicled jejunum reconstruction resulted in a lower anastomotic leak rate.

OBJECTIVE: Anorectal transplantation is a challenging procedure but a promising option for patients with weakened or completely absent anorectal function. SUMMARY BACKGROUND DATA: We constructed a canine model of anorectal transplantation, evaluated the long-term outcomes, and controlled rejection and infection in allotransplantation. METHODS: In the pudendal nerve function study, 6 dogs were randomly divided into 2 groups, transection and anastomosis, and were compared with a control using anorectal manometry, electromyography, and histological examination. In the anorectal transplantation model, 4 dogs were assigned to 4 groups: autotransplant, allotransplant with immunosuppression, allotransplant without immunosuppression, and normal control. Long-term function was evaluated by defecography, videography, and histological examination. RESULTS: In the pudendal nerve function study, anorectal manometry indicated that the anastomosis group recovered partial function 6 months postoperatively. Microscopically, the pudendal nerve and the sphincter muscle regenerated in the anastomosis group. Anorectal transplantation was technically successful with a 3-stage operation: colostomy preparation, anorectal transplantation, and stoma closure. The dog who underwent allotransplantation and immunosuppression had 2 episodes of mild rejection, which were reversed with methylprednisolone and tacrolimus. The dog who underwent allotransplantation without immunosuppression had a severe acute rejection that resulted in graft necrosis. Successful dogs had full defecation control at the end of the study. CONCLUSIONS: We describe the critical role of the pudendal nerve in anorectal function and the first long-term success with anorectal transplantation in a canine model. This report is a proof-of-concept study for anorectal transplantation as a treatment for patients with an ostomy because of anorectal dysfunction.

Cold ischemia times ranging from <6 h to as long as 24 h are generally quoted as the limits for attempting the replantation of amputated extremities. In this study, we aimed to assess the effect of hyperbaric carbon monoxide (CO) and oxygen (O2) on rat limb preservation. Donor rat limbs were preserved in a chamber filled with hyperbaric CO and O2 for 3 days (CO + O2 3 days) or 7 days (CO + O2 7 days). Positive and negative control groups were created by using non-preserved limbs (NP) and limbs wrapped in saline-moistened gauze for 3 days (SMG 3 days), respectively. The survival rate of transplanted limbs at postoperative day 90 was 88% in the NP and 86% in the CO + O2 3 days. The corresponding survival rate was 50% in the CO + O2 7 days at postoperative day 90 but was 0% in the SMG 3 days at postoperative day 3. Muscle mass decreased in the CO + O2 3 days and CO + O2 7 days compared with the NP, but sciatic-tibial nerve conduction velocities did not differ. These results indicate that amputated extremities preservation with hyperbaric CO and O2 could extend the time limits of preservation, maintaining their viability for replantation.

BACKGROUND: For managing major limb amputation, it is important to consider ischemic time and reperfusion injury by free radicals after the blood supply is reestablished. State of preservation during transplant surgery is crucial for the survival and function of the tissue, graft, or organ. In this study, we confirmed the effect of intermittent blood flow in rat ischemic hind limb and developed a new oxygenic preservation method using artificial oxygen carrying hemoglobin vesicles (HbVs). METHODS: We first compared a continuous ischemic model and an intermittent reflow model on rat hind limb. At postoperative day 7, hind limbs were evaluated. Next, we performed total amputation, normothermic preservation by perfusion with extracellular-trehalose-Kyoto (ETK) solution or HbV, and microsurgical replantation of the left hind limb. Venous efflux was analyzed, the amputated limb evaluated after 6 hr perfusion, and the replantation outcome of each model was compared. RESULTS: In our early study, 24 hr continuous ischemic model necrotized, but intermittent reflow model almost survived except for partial necrosis at postoperative day 7. Scar tissue on the right limb showed myonecrosis and infiltration of inflammatory cells. Skeletal muscle on the right limb was structurally well maintained. Hemoglobin vesicle-treated limbs appeared to have much better oxygenation than ETK-treated limbs. Aerobic respiration remained in the amputated limb, gastrocnemius muscle was well maintained, and the overall replantation was successful in the limb preserved using HbV. CONCLUSION: These studies demonstrated that oxygenic preservation is effective for rat ischemic limb, suggesting that this method may be useful for other replantation and transplantation surgeries.

This article evaluates the suitability of cadavers embalmed by the saturated salt solution (SSS) method for surgical skills training (SST). SST courses using cadavers have been performed to advance a surgeon's techniques without any risk to patients. One important factor for improving SST is the suitability of specimens, which depends on the embalming method. In addition, the infectious risk and cost involved in using cadavers are problems that need to be solved. Six cadavers were embalmed by 3 methods: formalin solution, Thiel solution (TS), and SSS methods. Bacterial and fungal culture tests and measurement of ranges of motion were conducted for each cadaver. Fourteen surgeons evaluated the 3 embalming methods and 9 SST instructors (7 trauma surgeons and 2 orthopedists) operated the cadavers by 21 procedures. In addition, ultrasonography, central venous catheterization, and incision with cauterization followed by autosuture stapling were performed in some cadavers. The SSS method had a sufficient antibiotic effect and produced cadavers with flexible joints and a high tissue quality suitable for SST. The surgeons evaluated the cadavers embalmed by the SSS method to be highly equal to those embalmed by the TS method. Ultrasound images were clear in the cadavers embalmed by both the methods. Central venous catheterization could be performed in a cadaver embalmed by the SSS method and then be affirmed by x-ray. Lungs and intestines could be incised with cauterization and autosuture stapling in the cadavers embalmed by TS and SSS methods. Cadavers embalmed by the SSS method are sufficiently useful for SST. This method is simple, carries a low infectious risk, and is relatively of low cost, enabling a wider use of cadavers for SST.

Colostomy is conventional treatment for anal dysfunction. Recently, a few trials of anorectal transplantation in animals have been published as a potential alternative to colostomies; however, further development of this technique is required. In this study, we utilized a canine model of anorectal transplantation, evaluated the patency of our microsurgical anastomoses, and assessed the perfusion of the transplanted anus. We designed a canine anorectal transplantation model, wherein anorectal autotransplantation was performed in four healthy beagle dogs by anastomoses of the lower rectum, the bilateral pudendal arteries (PAs) and veins (PVs), and pudendal nerves (PNs). Postoperative graft perfusion was measured by indocyanine green (ICG) angiography and histological examination. The length of the anorectal graft including perianal skin, anal sphincter muscle, bilateral PAs, PVs, and PNs was 4.9 ± 0.3 cm. All diameters of the PAs, PVs, and PNs were large enough to be microscopically anastomosed. Both ICG angiography and histological examination demonstrated good graft perfusion, except for one case that lead to venous congestion. These results show that anastomosis of the bilateral PAs, PVs, and PNs is required for anorectal transplantation. This is the first successful report of canine anorectal autotransplantation.

BACKGROUND: Hyperbaric oxygenation has been used for various purposes, but its clinical application is limited due to its pulmonary toxicity. We evaluated the therapeutic value of normobaric hyperoxygenation (NBO) for vascularized and nonvascularized tissue transplantation. METHODS: Tissue oxygen partial pressure (PtO2) was measured for various organs in mice under inspiratory oxygen of 20%, 60%, or 100%. A rectangular skin flap (1 × 4 cm) or a composite skin graft (2 × 2 cm) was made on the back of mice, which were housed under 20% or 60% oxygen for the first 3 days after surgery. Cell survival was also examined in organ culture skin samples. RESULTS: PtO2 varied among tissues/organs, but increased depending on inspiratory oxygen concentration in all tissues/organs. Although NBO with 100% O2 was toxic, NBO with 60% O2 was safe even when used continuously for a long period. NBO did not significantly improve survival of the rectangular skin flap. On the other hand, in the composite skin graft model, the engraftment area increased significantly (52 ± 10 at 20% vs 68 ± 5.1 at 60%) and contraction decreased significantly (42 ± 8.0 at 20% vs 27 ± 5.7 at 60%). Organ culture of a composite skin sample showed significant cell death under lower oxygen concentrations, supporting the data in vivo. CONCLUSIONS: The composite graft was maintained until revascularization by plasmatic diffusion from surrounding tissues, in which PtO2 was improved by NBO. NBO may be an effective adjunct therapy that can be performed readily after nonvascularized tissue grafting.

BACKGROUND: Anorectal transplantation is a method for patients who have lost their anorectal function or suffer from congenital anorectal dysfunction to recover this function, and this has been investigated in experimental animal models using pigs, dogs, and rats. In this study, we performed an examination of anorectal transplantation in human cadavers to investigate whether this procedure could be performed in patients. METHODS: A 77-year-old woman cadaver 1 was used as the donor and a 98-year-old woman cadaver 2 was used as the recipient. Initially, abdominoperineal excision of the anus and rectum (the Miles' operation) was performed on the recipient. Next, an anorectal graft containing the pudendal nerve (PN), pudendal artery (PA), pudendal vein (PV), inferior mesenteric artery (IMA), and inferior mesenteric vein (IMV) was harvested from the donor. The donor graft was transplanted into the recipient by intestinal anastomosis and microneurovascular anastomoses orthotopically. RESULTS: The diameters of the PN (right/left), IMA, and IMV were 2.5 mm/2.5 mm, 2.0 mm, and 1.5 mm, respectively, in cadaver 1, and 2.0 mm/2.0 mm, 2.0 mm, and 2.0 mm, respectively, in cadaver 2. The length of the PN, PA, PV, IMA, and IMV in the graft was sufficient to allow proper anastomosis. CONCLUSION: This preliminary study indicated that human anorectal transplantation was possible anatomically and technically. We anticipate our study will aid in the potential future application of this procedure to human patients.