Drug administration via hollow microneedles (HMN) have the advantages of painlessness, avoidance of first-pass effect, capability of sustained infusion, and no need for professional personnel operation. In addition, HMN can also be applied in the fields of body fluid extraction and biosensors, showing broad application prospects. However, traditional manufacturing technologies cannot meet the demand for low-cost mass production of HMN, limiting its widespread application. This paper reviews the main manufacturing technologies used for HMN in recent years, which include photolithography and etching, laser etching, sputtering and electroplating, micro-molding, three-dimensional (3D) printing and drawing lithography. It further analyzes the characteristics and limitations of existing manufacturing technologies and points out that the combination of various manufacturing technologies can improve production efficiency to a certain extent. In addition, this paper looks forward to the future trends of HMN manufacturing technology and proposes possible directions for its development. In conclusion, it is expected that this review can provide new ideas and references for follow-up research.
Printing, Three-Dimensional ; Needles ; Humans ; Drug Delivery Systems/methods* ; Equipment Design ; Microinjections/methods*

OBJECTIVE: To investigate the management strategies of external fixation combined with microsurgical techniques for repairing complex foot and ankle wounds in children. METHODS: The clinical data of 9 children with complex foot and ankle wounds who met the selection criteria between June 2017 and December 2021 was retrospectively analyzed. There were 6 boys and 3 girls, aged 3-13 years, with an average of 7.4 years. The causes of injury included crush injury in 5 cases and traffic accident injury in 4 cases. The wound size ranged from 6 cm×5 cm to 25 cm×18 cm. The time from injury to surgery ranged from 3 to 8 hours, with an average of 5 hours. All cases underwent staged surgical treatment. Among the 3 cases requiring deformity correction, 2 cases initially underwent free anterolateral thigh flap transplantation for wound coverage and limb salvage, followed by circular external fixation combined with osteotomy to address postoperative limb deformity, while 1 case received osteotomy for tibial fracture realignment prior to local pedicled flap reconstruction. All the 6 cases with non-deformity correction underwent initial external fixation followed by secondary flap reconstruction for wound management. The American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score was used to evaluate the foot and ankle function of children. RESULTS: All children successfully achieved limb salvage postoperatively. Among the 6 non-deformity correction cases, all flaps survived with satisfactory wound healing and no infection was observed; fractures healed within 2.5-4.5 months, after which external fixators were removed for functional rehabilitation with favorable recovery. One case treated with circular external fixation combined with osteotomy achieved bone union at 4 months postoperatively, followed by fixator removal. One case undergoing osteotomy for tibial fracture realignment showed bone healing at 2.5 months post-correction, with subsequent fixator removal. One patient receiving bone lengthening developed infection at 1 week postoperatively, which was managed with multiple debridements, ultimately achieving bone union at 16 months postoperatively and followed by fixator removal. At last follow-up, all patients demonstrated satisfactory ankle-hindfoot functional recovery, with AOFAS ankle-hindfoot scores ranging from 80 to 90 (mean, 84.2). CONCLUSION The combination of external fixation and microsurgical techniques demonstrates significant advantages in reconstructing complex foot and ankle wounds in children. The synergistic interaction provides both mechanical stability and biological repair, enabling early functional rehabilitation while reducing infection risks.
Humans ; Child ; Male ; Female ; Adolescent ; Child, Preschool ; Foot Injuries/surgery* ; Ankle Injuries/surgery* ; Retrospective Studies ; External Fixators ; Microsurgery/methods* ; Plastic Surgery Procedures/methods* ; Surgical Flaps ; Fracture Fixation/methods* ; Osteotomy/methods* ; Treatment Outcome

OBJECTIVE: To analyze the clinical efficacy and safety of microsurgery in patients with Gustilo ⅢC open fractures. METHODS: A total of 64 patients with Gustilo ⅢC open fractures who were admitted to the hospital bewteen September 2018 and March 2022 were included, and divided into the observation group and the control group, with 32 cases in each one. In the observation group, there were 24 males and 8 females, aged from 29 to 42 years with an average of (36.59±3.24) years. The tibial defect ranged from 2 to 5 cm with an average of (3.41±0.61) cm, and the soft tissue defect area ranged from 34 to 76 cm2 with an average of (58.50±9.44) cm2. This group received microsurgical treatment. In the control group, there were 25 males and 7 females, aged from 27 to 44 years with an average of (37.59±3.21) years. The tibial defect ranged from 2 to 6 cm with an average of (3.59±0.80) cm, and the soft tissue defect area ranged from 36 to 78 cm2 with an average of (59.09±9.53) cm2. This group received conventional staged surgery, with plaster or brace fixation after initial debridement and appropriate internal fixation at a later stage. The Anderson scores, motor ability Fugl-Meyer scale, perioperative indicators, rehabilitation outcomes, and complications were compared between the two groups. RESULTS: The patients were followed up for a duration from 2.5 to 5.5 months with an average of (3.15±1.11) months. In the observation group, 19 patients were rated as excellent, 12 patients as good, 1 patient as fair, and no patients as poor. In the control group, 11 patients were rated as excellent, 13 patients as good, 6 patients as fair, and 2 patients as poor. The difference in outcomes between the two groups was statistically significant (P<0.05). The operation time, the hospitalization time, and the hospitalization cost in the observation group(4.39±0.69) h, (30.22±4.58) d, and (23, 500±3, 300) yuan, respectively were significantly lower than those in the control group(5.01±0.75) h, (33.28±3.74) d, and(30, 200±5, 200) yuan, respectively (P<0.05). Revascularization time(134.25±14.76) h, wound healing time(11.34±1.56) d, and fracture healing time(3.09±0.42) months in the observation group were significantly shorter than those in the control group(P<0.05) which were (189.36±22.17) h, (13.22±2.03) d and (4.02±0.57) months respectively. The motor ability(42.91±5.51) points, sensory function(46.19±3.53) points, and total Fugl-Meyer score(89.09±6.08) in the observation group were significantly higher than those in the control group(P<0.05) which were(35.19±4.27), (34.03±3.79), (69.22±6.32) points respectivdy. In the observation group, there were 1 case of refractory wound and 3 cases of complete nerve injury, which were lower than those in the control group (8 cases and 10 cases, respectively, P<0.05). The number of complications in the observation group was lower than that in the control group (P<0.05). CONCLUSION Microsurgical technique can effectively shorten the wound and fracture healing time in patients with Gustilo Ⅲ C open fracture, improve limb movement ability, and reduce the risk of poor prognosis and complications.
Humans ; Male ; Female ; Adult ; Fractures, Open/surgery* ; Microsurgery/methods* ; Treatment Outcome

Testicular tumor is the most common solid malignancy in males under 40 years of age. This malignancy is known to have a negative impact on male fertility. Therefore, several techniques for sperm retrieval have been proposed, including microdissection testicular sperm extraction (mTESE). The objective of this study was to review the literature on the outcomes of oncological (Onco)-mTESE at the time of radical orchiectomy. We conducted a comprehensive literature search through PubMed, Scopus, and Cochrane Central Controlled Register of Trials. Only studies reporting ex vivo mTESE in patients with testicular tumor were considered. Twelve papers met the inclusion criteria and were included in this review. Tumor size was identified as the sole preoperative factor influencing spermatogenesis. The considered studies demonstrated a satisfactory success rate for Onco-mTESE, associated with a similarly valid percentage of live healthy births through assisted reproductive technology. Currently, no comparison has been made between Onco-mTESE and conventional Onco-TESE, hence further assessment is required. In cases where the tumor completely replaces the cancer-bearing testicle, a contralateral micro-TESE may be a viable alternative. However, the surgeon should evaluate associated risks and benefits preoperatively. In conclusion, Onco-mTESE at the time of radical orchiectomy appears to be a promising therapeutic option for young patients with testicular tumors. Nevertheless, additional studies are necessary to achieve a definitive conclusion.
Humans ; Male ; Azoospermia/etiology* ; Sperm Retrieval ; Orchiectomy/methods* ; Testicular Neoplasms/complications* ; Microdissection/methods* ; Testis/surgery* ; Adult

When microdissection testicular sperm extraction (micro-TESE) fails, a redo procedure may be the only option for patients who want a biological child. However, there are many gaps of knowledge surrounding the procedure, which need to be addressed to help clinicians and patients make informed decisions. This review explores redo micro-TESE in the context of nonobstructive azoospermia (NOA). Literature was searched using Google Scholar, Medline, and PubMed. Search terms were "NOA" AND "second microdissection testicular sperm extractions" AND "redo microdissection testicles sperm extraction" AND "repeat microdissection testicular sperm extractions" AND "failed microdissection testicular sperm extractions" AND "salvage microdissection testicular sperm extractions". Only original articles in English were included. A total of nine articles were included, consisting of four retrospective and five prospective studies. The time gap between the first and second micro-TESE varied from 6 months to 24 months. Most of the included studies reported successful surgical sperm retrieval (SSR) in the second micro-TESE in the range of 10%-21%, except in one study where it reached 42%. It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE. Patients with hypospermatogenesis and Klinefelter syndrome (KS) had the highest chance of success in redo surgery. In conclusion, redo micro-TESE following a negative procedure can lead to sperm recovery in 10%-21%. Patients with hypospermatogenesis and KS have a higher chance of success. There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.
Humans ; Male ; Azoospermia/surgery* ; Sperm Retrieval ; Microdissection ; Reoperation ; Treatment Failure ; Testis/surgery* ; Treatment Outcome

Nonobstructive azoospermia (NOA) is the most challenging and complex clinical scenario for infertile men. Besides circumstances such as hypogonadotropic hypogonadism, surgical sperm retrieval is typically necessary, and microdissection testicular sperm extraction (micro-TESE) is the procedure of choice for men with NOA desiring to father children with their own gametes. Micro-TESE results in the highest numbers of sperm cells retrieved for use with in vitro fertilization/intracytoplasmic sperm injection (ICSI) in comparison to all other techniques for surgical sperm retrieval in men with NOA. Several factors may affect sperm retrieval rate and ICSI outcomes, including the patient's age, testicular volume, histopathological and genetic profile, and serum hormone levels. This article aims to review the medical literature describing predictors of successful micro-TESE and the outcomes of ICSI in men with NOA.
Humans ; Azoospermia/surgery* ; Male ; Sperm Injections, Intracytoplasmic ; Sperm Retrieval ; Treatment Outcome ; Testis/pathology* ; Female ; Microdissection

Nonobstructive azoospermia (NOA) is considered the most challenging clinical scenario for infertile men and current treatments leave many men unsuccessful at being able to achieve a pregnancy with their partner using their own sperm. Microdissection testicular sperm extraction (micro-TESE) is the choice for men with NOA desiring to father children with their own gametes. Micro-TESE results in the highest numbers of sperm cells retrieved for use with in vitro fertilization/intracytoplasmic sperm injection. With suboptimal micro-TESE success rates of sperm retrieval and then pregnancy and live birth using the retrieved sperm with in vitro fertilization/intracytoplasmic sperm injection, advances to improve outcomes are necessary. This article comprehensively reviews the technologies investigated to date to improve the outcomes for men undergoing micro-TESE.
Humans ; Male ; Sperm Retrieval ; Azoospermia/surgery* ; Pregnancy ; Female ; Sperm Injections, Intracytoplasmic ; Microdissection/methods* ; Fertilization in Vitro ; Testis/surgery*

Except in cases of hypogonadotropic hypogonadism, the use of medical therapy before microsurgical testicular sperm extraction (micro-TESE) is controversial. In some studies, hormone therapy has been shown to improve the possibility of sperm retrieval during micro-TESE and even lead to the presence of sperm in the ejaculate in some cases, thereby obviating the need for micro-TESE. However, their routine use before micro-TESE in cases of nonobstructive azoospermia (NOA) being associated with hypergonadotropic hypogonadism and eugonadism (normogonadotropic condition) has not been supported with robust evidence. In this review, we discuss different types of medical therapy used before micro-TESE for NOA, their risks and benefits, and the available evidence surrounding their use in this setting.
Humans ; Male ; Azoospermia/therapy* ; Sperm Retrieval ; Hypogonadism/complications* ; Microsurgery

To investigate the impact of preoperative serum follicle-stimulating hormone (FSH) levels on the probability of testicular sperm retrieval, we conducted a study of nonobstructive azoospermic (NOA) men with different testicular volumes (TVs) who underwent microdissection testicular sperm extraction (micro-TESE). A total of 177 NOA patients undergoing micro-TESE for the first time from April 2019 to November 2022 in Shenzhen Zhongshan Obstetrics and Gynecology Hospital (formerly Shenzhen Zhongshan Urology Hospital, Shenzhen, China) were retrospectively reviewed. The subjects were divided into four groups based on average TV quartiles. Serum hormone levels in each TV group were compared between positive and negative sperm retrieval subgroups. Overall sperm retrieval rate was 57.6%. FSH levels (median [interquartile range]) were higher in the positive sperm retrieval subgroup compared with the negative outcome subgroup when average TV was <5 ml (first quartile [Q1: TV <3 ml]: 43.32 [17.92] IU l -1 vs 32.95 [18.56] IU l -1 , P = 0.048; second quartile [Q2: 3 ml ≤ TV <5 ml]: 31.31 [15.37] IU l -1 vs 25.59 [18.40] IU l -1 , P = 0.042). Elevated serum FSH levels were associated with successful micro-TESE sperm retrieval in NOA men whose average TVs were <5 ml (adjusted odds ratio [OR]: 1.06 per unit increase; 95% confidence interval [CI]: 1.01-1.11; P = 0.011). In men with TVs ≥5 ml, larger TVs were associated with lower odds of sperm retrieval (adjusted OR: 0.84 per 1 ml increase; 95% CI: 0.71-0.98; P = 0.029). In conclusion, elevated serum FSH levels were associated with positive sperm retrieval in micro-TESE in NOA men with TVs <5 ml. In men with TV ≥5 ml, increases in average TVs were associated with lower odds of sperm retrieval.
Humans ; Male ; Azoospermia/surgery* ; Sperm Retrieval/statistics & numerical data* ; Adult ; Follicle Stimulating Hormone/blood* ; Retrospective Studies ; Testis/pathology* ; Microdissection ; Organ Size

Infertility, defined as the inability to conceive after 1 year of regular unprotected intercourse, impacts 10%-20% of couples globally. Both male and female factors contribute equally to this condition. Azoospermia, particularly nonobstructive azoospermia (NOA), which affects 10%-15% of infertile men, represents a significant challenge in male infertility. The advent of assisted reproductive technology (ART), specifically microdissection testicular sperm extraction (micro-TESE) followed by intracytoplasmic sperm injection (ICSI), offers a possibility for men with NOA to father biological children. Recent studies have focused on the predictors of sperm retrieval in NOA patients, such as age, testicular volume, and follicle-stimulating hormone (FSH) level. This review aims to explore the limited data on the anatomical characteristics of NOA patients and provide surgical considerations for micro-TESE, thereby enhancing understanding and improving outcomes for this challenging condition.
Humans ; Azoospermia/surgery* ; Male ; Testis/pathology* ; Sperm Retrieval ; Scrotum/pathology* ; Sperm Injections, Intracytoplasmic ; Microdissection